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Darrenf

Solution required for load shedding, Gurus please help ...

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Hi all,

Total newb here ready to pull the trigger on a solution to load shedding when it starts again...

Here is my info...

I don't really know how to calculate the amount of power required but I am on prepaid and the entire household uses between 10 an 20 KWH a day.

I am not worried about cooking and keeping everything working and would just like to have the following items running during load shedding (up to 4 hours).

  • 55" OLED TV
  • Home Theater pc (Proliant microserver)
  • Be able to charge 2 laptops for work if they go flat
  • Wifi Router (Fibre)
  • A lamp
  • "optional gaming console (Ps4)

That is my essentials to keep live during load shedding and working from home. I would like something somewhat portable and have batteries etc. included like the Mecer expert and that I can keep plugged in next to the TV Unit where all of the above items are using one single plug. Excuse my ignorance but I have research and all the technical jargon just confuses me.

My budget is between 15k to 20k and I would like something reliable and that wont damage my appliances.

From digging around on this forum I have had a look at the Mecer Axpert 3000VA but really am clueless.

Please could you aid me with some advice for my requirements.

 

Thank you all in advance...

Darren

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Two questions:

1. How easy would it be to isolate those circuits you absolutely require? It sounds like they are all just plug circuits, but they might not be on the same circuit.

2. Will you be able to keep your load low on those circuits when Eskom is available? If not, you’ll need something with a high AC transfer ability.

Your backup needs don’t seem to be very high, and for the basics you have listed, you’d probably be able to get away with a relatively small battery. However, your budget is somewhat limited especially since you would need to get an electrician as well to install and CoC the whole thing. The cost of that would be case specific but a second DB would be required, for example.

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HI there,

Firstly thanks for your response!

1. yes currently all on one plug (well the TV, HT server and fiber are all on one circuit. Isolating them is easy as they all fit onto one circuit behind the TV stand.

2. very easily, we don't have to charge phones or laptops unless its an emergency as they will stay charged while there is normal power.

WIth your comment on getting an electrician to setup, are there any standalone device which could just service the stated without that as we are not owners of the property?

 

 

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1 hour ago, Darrenf said:

HI there,

Firstly thanks for your response!

1. yes currently all on one plug (well the TV, HT server and fiber are all on one circuit. Isolating them is easy as they all fit onto one circuit behind the TV stand.

2. very easily, we don't have to charge phones or laptops unless its an emergency as they will stay charged while there is normal power.

WIth your comment on getting an electrician to setup, are there any standalone device which could just service the stated without that as we are not owners of the property?

 

 

If you want something that does not need to be installed, and all your essentials are on one plug, you might want to look at one of those portable trolley inverter kits. This one from takelot is just an example, I don't have personal experience with it. It will run you under R15k for the inverter and 2 deep cycle batteries.

Screenshot_20200701-081915_Chrome.jpg

Screenshot_20200703-214051_Chrome.jpg

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Posted (edited)

This one will do all that you want and more. Just keep it plugged into the wall and your devices into the inverter and it will change over automatically.

https://www.geewiz.co.za/long-run-ups-inverter-battery/93614-1030-mecer-axpert-3000va-pure-sine-inverter-2x-100ah-battery-8-hour-battery-life-kit-3000w.html#/132-battery_type-100ah_standard_200_250_cycles

 

LoadShedding.PNG

Edited by GVC

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You just need a UPS. Those Mecer's aren't bad UPSes. Though of course I'd still love to rather sell you a small Multiplus, like the kits Sustainable have (comes with a LiFePO4 battery with significantly better cycle life).

Must say though, I love how the above ad advertises an 8-hour battery life without saying what kind of load it can do for that 8 hours. If your total load is under 300W, and you kill the batteries completely every time, then yes, you'll be able to do 8 hours. Your max continuous load will be around 500W (that would give a pretty steep C/5 discharge rate on the batteries).

500W should be sufficient for the appliances you listed though.

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10 hours ago, Darrenf said:

WIth your comment on getting an electrician to setup, are there any standalone device which could just service the stated without that as we are not owners of the property?

Sorry! I completely missed the second paragraph of your original post. Yeah, one of those portable UPSes would be perfect. No need for installation! 😄

Like plonkster said, a UPS with a lithium battery will give you much better longevity. If Eskom is going to go into multiple load shedding cycles every day and you need something to last you a long time, a lithium battery option would be better. They are of course more expensive so you would need to do a bit of a cost benefit analysis.

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Posted (edited)

late to the party but brought my own drinks so will hang around in the parking lot...and in the spirit of "give a man a fish blah blah... but teach him to hot wire a car..."

EDIT: @Darrenf noticed I bombarded you previously with my rambling, you are welcome to ask for more clarification/explanation 🙂

On 2020/07/03 at 7:35 PM, Darrenf said:

Total newb here ready to pull the trigger on a solution to load shedding when it starts again...

I don't really know how to calculate the amount of power required but I am on prepaid and the entire household uses between 10 an 20 KWH a day.

Don't worry about total household consumption since you only want to power a couple of very specific things.

Ideally get some form of power meter (about R500 from what ever your flavour of online shop)... .or less ideal check each "appliance" for the label that shows you the power rating (like a 2000W kettle).... or search online for general estimates since many appliances don't actually list the power rating (my TV does not... but I checked my 47" (OLD school, not OLED) TV, AV amplifier, android TV box thingi, and B315 router all combined average about 125W).

Add all the various power requirements up and you will probably not even pass 500W (but if possible check your own numbers). So you could probably get by with a 500-800W inverter.

Now multiply the total power requirement by hours you want to power it for. 4h * 500W =2000Wh - this is technically how much energy you will need from a battery to power these things. Because energy conversion is not perfect and to allow some extra room, add an efficiency factor of 80%.... devide the 2000Wh by 0.8... 2000Wh/0.8 = 2500Wh will be a safer number to work with.

Here is where things can seem to become too technical but soldier on...., batteries will specify their voltage (12V, 24V, 48V most common) and their storage ability (in either Amp hour (Ah) or Watt hour (Wh)). Lithium batteries often specify the capacity in Wh and lead acid batteries in Ah. So how do you decide if a given battery will be "big" enough? Lithium just compare the Wh numbers. For lead acid (like the adds posted in this thread) take YOUR Wh number and devide it by the listed battery voltage. The first add has a single 12V 100Ah battery. So...2500Wh/12V = 208Ah. You will need a 208Ah 12V lead acid battery to power 500W for 4 hours - so a single battery like the one add will not be enough since it is a 100Ah battery. You can connect two 100Ah batteries in parallel then you will have a 200Ah but still 12V battery, so two of  those batteries might be needed (or maybe two 60Ah batteries?....read on first).

The second add says it comes with 2 batteries.... but if you check the specifications you will likely find that the inverter works on 24V (the two batteries are connected in series), so you have a 100Ah 24V battery (even though it is made with two 100Ah 12V batteries).... will the 2 batteries be big enough?... 2500Wh/24V = 104Ah... so this is closer.

BUT lead acid batteries do not have a very long total life before they "break" if you tend to use more than 50% of their capacity. So if looking at lead acid battery systems you will make life simpler if you take your power requirement and double it from the start. 2500Wh * 2 = 5000Wh.... 5000Wh/12V~400Ah.... or 5000Wh/24V~200Ah. So whether you go with 12V or 24V you will need at least four 100Ah batteries (or eight 50Ah batteries or two 200Ah batteries). Lithium batteries will generally let you use about 90% of their capacity but lithium is heavy on the pocket (depending how you do your sums)

I attached an excel sheet which can help you play around with some numbers. Change the battery voltage and time (in red font) as you need/want and add your appliances+watts in the yellow columns to the list. Since this is about load shedding you should also look at things lile time available to recharge the batteries (the sheet will show you how much time you need depending on the charger capacity to recharge the battery). Use at own risk (do not use it to make calculations to power grandma's iron lung)

On 2020/07/03 at 7:35 PM, Darrenf said:

That is my essentials to keep live during load shedding and working from home. I would like something somewhat portable and have batteries etc. included like the Mecer expert and that I can keep plugged in next to the TV Unit where all of the above items are using one single plug. 

My budget is between 15k to 20k and I would like something reliable and that wont damage my appliances.

Any of the mentioned systems should meet your inverter requirement but I suspect you will end up with a flat battery often and/or have to buy new batteries after a couple of months.

The "off-the-shelf" solutions can generally be made up cheaper by just combining everything yourself. I would personally not install the Axpert inverter laying flat though (like in the add)... pretty sure the unit thermal regulation was designed around a vertical install. If you can change a plug on a toaster you should be able to make up a system - especially for your listed needs. If not comfortable doing that - no shame in that (and stay out of the DB!).

Another option to the miriad of "ready made" UPS type systems that you can look at in your budget is something like a DIY victron multiplus 12/800 inverter charger (R8500-9500) combined with a second life Mecer 200Ah/2500Wh 12V lithium battery (R6400-R7500). Add a victron Mk3 USB cable (R1200) so you can make some changes to the inverter settings from a laptop. Get a battery place to make you up some 25mm2 cable with properly crimped lugs, add a fuse between battery and inverter, put it on trolley in a box (make sure the battery terminals are at least covered) if you want and you should have the lightest, least intrusive system that should meet your power needs in terms of inverter power, fast enough charger for most load shedding scenarios, and with a bit of careful load management your total storage capacity should be enough.

The axpert type systems definitely are lower cost and simpler (no extra cable/laptop needed for changing settings) and you have a screen to see what is happening. Especially the 3000W inverters give you more options to power something like a kettle if you really need to (not gonna do that with a 800W any inverter). The axpert type systems also generally add the option out of the box that you can add solar panels later without needing any other bits than solar panels, solar cable and solar fuse/disconnects.

If you think/gamble that load shedding will only be around now-and-again for a day or two and you want to keep this grudge purchase as cheap as possible, then also consider just battery, a separate smallish inverter and a loose battery charger. (keep charger connected to battery, when load shedding comes around, hook up the inverter... when load shedding goes away again for 3 months... put inverter in cupboard). Here you will just lose out on the automatic/"seemless" switch over when load shedding happens that you get with the axpert/multiplus type systems.

If going axpert type system - try and make sure it is an original voltronic produced inverter (quality and support on the clones seems somewhat iffy).

last thing... Just a note on having any system next to the TV... all these systems contain fans that switch on at least when charging the battery at a high rate and possibly when powering the load... you could find that it bothers you if right next to the TV.

whoop-whooop...that's the sound of the police... off I go..

LoadShed_Calc.xlsx

Edited by introverter
EDIT

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6 minutes ago, introverter said:

about R500 from what ever your flavour of online shop

Those things are quite excellent! They use some Chinese chip called the v9261f. Big Clive did a test too. And there are guys who hacked these to interface them with an ESP32 so they can talk to an mqtt server.

 

11 minutes ago, introverter said:

Any of the mentioned systems should meet your inverter requirement but I suspect you will end up with a flat battery often and/or have to buy new batteries after a couple of months.

Agreed. The loads mentioned will get you a 50% DoD (estimated, by me) on a standard 2 hour load-shedding slot, and on the double-slot (level 5 and up in Cape Town, but much earlier in Jhb) will see you run out just about every time. The standard batteries people use with those 24V Mecer trolleys won't last 3 months with that kind of abuse.

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19 minutes ago, introverter said:

late to the party but brought my own drinks so will hang around in the parking lot...and in the spirit of "give a man a fish blah blah... but teach him to hot wire a car..."

EDIT: @Darrenf noticed I bombarded you previously with my rambling, you are welcome to ask for more clarification/explanation 🙂

Don't worry about total household consumption since you only want to power a couple of very specific things.

Ideally get some form of power meter (about R500 from what ever your flavour of online shop)... .or less ideal check each "appliance" for the label that shows you the power rating (like a 2000W kettle).... or search online for general estimates since many appliances don't actually list the power rating (my TV does not... but I checked my 47" (OLD school, not OLED) TV, AV amplifier, android TV box thingi, and B315 router all combined average about 125W).

Add all the various power requirements up and you will probably not even pass 500W (but if possible check your own numbers). So you could probably get by with a 500-800W inverter.

Now multiply the total power requirement by hours you want to power it for. 4h * 500W =2000Wh - this is technically how much energy you will need from a battery to power these things. Because energy conversion is not perfect and to allow some extra room, add an efficiency factor of 80%.... devide the 2000Wh by 0.8... 2000Wh/0.8 = 2500Wh will be a safer number to work with.

Here is where things can seem to become too technical but soldier on...., batteries will specify their voltage (12V, 24V, 48V most common) and their storage ability (in either Amp hour (Ah) or Watt hour (Wh)). Lithium batteries often specify the capacity in Wh and lead acid batteries in Ah. So how do you decide if a given battery will be "big" enough? Lithium just compare the Wh numbers. For lead acid (like the adds posted in this thread) take YOUR Wh number and devide it by the listed battery voltage. The first add has a single 12V 100Ah battery. So...2500Wh/12V = 208Ah. You will need a 208Ah 12V lead acid battery to power 500W for 4 hours - so a single battery like the one add will not be enough since it is a 100Ah battery. You can connect two 100Ah batteries in parallel then you will have a 200Ah but still 12V battery, so two of  those batteries might be needed (or maybe two 60Ah batteries?....read on first).

The second add says it comes with 2 batteries.... but if you check the specifications you will likely find that the inverter works on 24V (the two batteries are connected in series), so you have a 100Ah 24V battery (even though it is made with two 100Ah 12V batteries).... will the 2 batteries be big enough?... 2500Wh/24V = 104Ah... so this is closer.

BUT lead acid batteries do not have a very long total life before they "break" if you tend to use more than 50% of their capacity. So if looking at lead acid battery systems you will make life simpler if you take your power requirement and double it from the start. 2500Wh * 2 = 5000Wh.... 5000Wh/12V~400Ah.... or 5000Wh/24V~200Ah. So whether you go with 12V or 24V you will need at least four 100Ah batteries (or eight 50Ah batteries or two 200Ah batteries). Lithium batteries will generally let you use about 90% of their capacity but lithium is heavy on the pocket (depending how you do your sums)

I attached an excel sheet which can help you play around with some numbers. Change the battery voltage and time (in red font) as you need/want and add your appliances+watts in the yellow columns to the list. Since this is about load shedding you should also look at things lile time available to recharge the batteries (the sheet will show you how much time you need depending on the charger capacity to recharge the battery). Use at own risk (do not use it to make calculations to power grandma's iron lung)

Any of the mentioned systems should meet your inverter requirement but I suspect you will end up with a flat battery often and/or have to buy new batteries after a couple of months.

The "off-the-shelf" solutions can generally be made up cheaper by just combining everything yourself. I would personally not install the Axpert inverter laying flat though (like in the add)... pretty sure the unit thermal regulation was designed around a vertical install. If you can change a plug on a toaster you should be able to make up a system - especially for your listed needs. If not comfortable doing that - no shame in that (and stay out of the DB!).

Another option to the miriad of "ready made" UPS type systems that you can look at in your budget is something like a DIY victron multiplus 12/800 inverter charger (R8500-9500) combined with a second life Mecer 200Ah/2500Wh 12V lithium battery (R6400-R7500). Add a victron Mk3 USB cable (R1200) so you can make some changes to the inverter settings from a laptop. Get a battery place to make you up some 25mm2 cable with properly crimped lugs, add a fuse between battery and inverter, put it on trolley in a box (make sure the battery terminals are at least covered) if you want and you should have the lightest, least intrusive system that should meet your power needs in terms of inverter power, fast enough charger for most load shedding scenarios, and with a bit of careful load management your total storage capacity should be enough.

The axpert type systems definitely are lower cost and simpler (no extra cable/laptop needed for changing settings) and you have a screen to see what is happening. Especially the 3000W inverters give you more options to power something like a kettle if you really need to (not gonna do that with a 800W any inverter). The axpert type systems also generally add the option out of the box that you can add solar panels later without needing any other bits than solar panels, solar cable and solar fuse/disconnects.

If you think/gamble that load shedding will only be around now-and-again for a day or two and you want to keep this grudge purchase as cheap as possible, then also consider just battery, a separate smallish inverter and a loose battery charger. (keep charger connected to battery, when load shedding comes around, hook up the inverter... when load shedding goes away again for 3 months... put inverter in cupboard). Here you will just lose out on the automatic/"seemless" switch over when load shedding happens that you get with the axpert/multiplus type systems.

If going axpert type system - try and make sure it is an original voltronic produced inverter (quality and support on the clones seems somewhat iffy).

last thing... Just a note on having any system next to the TV... all these systems contain fans that switch on at least when charging the battery at a high rate and possibly when powering the load... you could find that it bothers you if right next to the TV.

whoop-whooop...that's the sound of the police... off I go..

LoadShed_Calc.xlsx 12.73 kB · 0 downloads

 

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19 minutes ago, introverter said:

late to the party but brought my own drinks so will hang around in the parking lot...and in the spirit of "give a man a fish blah blah... but teach him to hot wire a car..."

EDIT: @Darrenf noticed I bombarded you previously with my rambling, you are welcome to ask for more clarification/explanation 🙂

Don't worry about total household consumption since you only want to power a couple of very specific things.

Ideally get some form of power meter (about R500 from what ever your flavour of online shop)... .or less ideal check each "appliance" for the label that shows you the power rating (like a 2000W kettle).... or search online for general estimates since many appliances don't actually list the power rating (my TV does not... but I checked my 47" (OLD school, not OLED) TV, AV amplifier, android TV box thingi, and B315 router all combined average about 125W).

Add all the various power requirements up and you will probably not even pass 500W (but if possible check your own numbers). So you could probably get by with a 500-800W inverter.

Now multiply the total power requirement by hours you want to power it for. 4h * 500W =2000Wh - this is technically how much energy you will need from a battery to power these things. Because energy conversion is not perfect and to allow some extra room, add an efficiency factor of 80%.... devide the 2000Wh by 0.8... 2000Wh/0.8 = 2500Wh will be a safer number to work with.

Here is where things can seem to become too technical but soldier on...., batteries will specify their voltage (12V, 24V, 48V most common) and their storage ability (in either Amp hour (Ah) or Watt hour (Wh)). Lithium batteries often specify the capacity in Wh and lead acid batteries in Ah. So how do you decide if a given battery will be "big" enough? Lithium just compare the Wh numbers. For lead acid (like the adds posted in this thread) take YOUR Wh number and devide it by the listed battery voltage. The first add has a single 12V 100Ah battery. So...2500Wh/12V = 208Ah. You will need a 208Ah 12V lead acid battery to power 500W for 4 hours - so a single battery like the one add will not be enough since it is a 100Ah battery. You can connect two 100Ah batteries in parallel then you will have a 200Ah but still 12V battery, so two of  those batteries might be needed (or maybe two 60Ah batteries?....read on first).

The second add says it comes with 2 batteries.... but if you check the specifications you will likely find that the inverter works on 24V (the two batteries are connected in series), so you have a 100Ah 24V battery (even though it is made with two 100Ah 12V batteries).... will the 2 batteries be big enough?... 2500Wh/24V = 104Ah... so this is closer.

BUT lead acid batteries do not have a very long total life before they "break" if you tend to use more than 50% of their capacity. So if looking at lead acid battery systems you will make life simpler if you take your power requirement and double it from the start. 2500Wh * 2 = 5000Wh.... 5000Wh/12V~400Ah.... or 5000Wh/24V~200Ah. So whether you go with 12V or 24V you will need at least four 100Ah batteries (or eight 50Ah batteries or two 200Ah batteries). Lithium batteries will generally let you use about 90% of their capacity but lithium is heavy on the pocket (depending how you do your sums)

I attached an excel sheet which can help you play around with some numbers. Change the battery voltage and time (in red font) as you need/want and add your appliances+watts in the yellow columns to the list. Since this is about load shedding you should also look at things lile time available to recharge the batteries (the sheet will show you how much time you need depending on the charger capacity to recharge the battery). Use at own risk (do not use it to make calculations to power grandma's iron lung)

Any of the mentioned systems should meet your inverter requirement but I suspect you will end up with a flat battery often and/or have to buy new batteries after a couple of months.

The "off-the-shelf" solutions can generally be made up cheaper by just combining everything yourself. I would personally not install the Axpert inverter laying flat though (like in the add)... pretty sure the unit thermal regulation was designed around a vertical install. If you can change a plug on a toaster you should be able to make up a system - especially for your listed needs. If not comfortable doing that - no shame in that (and stay out of the DB!).

Another option to the miriad of "ready made" UPS type systems that you can look at in your budget is something like a DIY victron multiplus 12/800 inverter charger (R8500-9500) combined with a second life Mecer 200Ah/2500Wh 12V lithium battery (R6400-R7500). Add a victron Mk3 USB cable (R1200) so you can make some changes to the inverter settings from a laptop. Get a battery place to make you up some 25mm2 cable with properly crimped lugs, add a fuse between battery and inverter, put it on trolley in a box (make sure the battery terminals are at least covered) if you want and you should have the lightest, least intrusive system that should meet your power needs in terms of inverter power, fast enough charger for most load shedding scenarios, and with a bit of careful load management your total storage capacity should be enough.

The axpert type systems definitely are lower cost and simpler (no extra cable/laptop needed for changing settings) and you have a screen to see what is happening. Especially the 3000W inverters give you more options to power something like a kettle if you really need to (not gonna do that with a 800W any inverter). The axpert type systems also generally add the option out of the box that you can add solar panels later without needing any other bits than solar panels, solar cable and solar fuse/disconnects.

If you think/gamble that load shedding will only be around now-and-again for a day or two and you want to keep this grudge purchase as cheap as possible, then also consider just battery, a separate smallish inverter and a loose battery charger. (keep charger connected to battery, when load shedding comes around, hook up the inverter... when load shedding goes away again for 3 months... put inverter in cupboard). Here you will just lose out on the automatic/"seemless" switch over when load shedding happens that you get with the axpert/multiplus type systems.

If going axpert type system - try and make sure it is an original voltronic produced inverter (quality and support on the clones seems somewhat iffy).

last thing... Just a note on having any system next to the TV... all these systems contain fans that switch on at least when charging the battery at a high rate and possibly when powering the load... you could find that it bothers you if right next to the TV.

whoop-whooop...that's the sound of the police... off I go..

LoadShed_Calc.xlsx 12.73 kB · 0 downloads

Thanks for all this info I shall definitely take the listed into consideration. Thank you so much

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Right so after rabbit holing for a week I have decided to go with one of the 2 options and be done with it lol

So if you had the choice between the 2 which one would ya order? :)

https://www.geewiz.co.za/load-shedding-solutions/111207-1048-axpert-type-pure-sine-3000va-inverter-2x-100ah-battery-8-hour-battery-life-kit-3000w-80a-solar.html#/132-battery_type-100ah_standard_200_250_cycles

https://www.geewiz.co.za/long-run-ups-inverter-battery/93614-1030-mecer-axpert-3000va-pure-sine-inverter-2x-100ah-battery-8-hour-battery-life-kit-3000w.html#/132-battery_type-100ah_standard_200_250_cycles

Price is negligible between the 2 and I will just replace batteries one day, or hopefully buy a place and get a proper built in system, for now one of these seem will serve my immediate purpose.

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5 hours ago, Darrenf said:

Price is negligible between the 2 and I will just replace batteries one day, or hopefully buy a place and get a proper built in system, for now one of these seem will serve my immediate purpose.

It's exactly the same inverter. Voltronic makes them, and other people rebadge them.

That's a budget inverter. Of course there are plenty worse inverters on the market, and this one is not a bad one for just a UPS... but you will buy something else within the net 5 years or so. That's almost a given 🙂

 

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6 hours ago, plonkster said:

but you will buy something else within the net 5 years or so. That's almost a given 🙂

And replace the batteries a few times before that 5 years are over. I have stopped supplying replacement batteries to clients with those trolleys because they think its my fault that the batteries only last a year before they need to replace them. 

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8 hours ago, plonkster said:

It's exactly the same inverter. Voltronic makes them, and other people rebadge them.

That's a budget inverter. Of course there are plenty worse inverters on the market, and this one is not a bad one for just a UPS... but you will buy something else within the net 5 years or so. That's almost a given 🙂

 

Thanks Plonkster

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2 hours ago, Jaco de Jongh said:

And replace the batteries a few times before that 5 years are over. I have stopped supplying replacement batteries to clients with those trolleys because they think its my fault that the batteries only last a year before they need to replace them. 

Thanks Jaco, any suggestions on how maintain those batteries or any other suggestions?

 

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Posted (edited)
1 hour ago, Darrenf said:

any suggestions on how maintain those batteries or any other suggestions?

My experience with this is that you have basically two groups of batteries. You can buy below 5k ZAR or above it. Now most people are going to buy the cheaper battery because they just spent 9k-10k for the inverter-trolley... so quite understandable the spectre of increasing that investment is somewhat adrenaline-inducing. But the trouble with those cheaper batteries is that they just don't hold up, regardless of how well you treat them. One year in, maybe 18 months... there you are with one bad cell neatly packaged with 5 good ones, and no option but to replace the entire bank.

Treat them badly, eg discharging them too deeply, and you're looking at not even 6 months.

If you buy a good AGM battery though, and you treat them well, you could well be okay for 3 years or more. And by good I mean something like your Victron AGM or Gel batteries.

However, what happens to most people is that once load-shedding stops, you forget to look after the batteries, until the next time load-shedding starts. In an ideal world just keeping the batteries floated should be all you need to do (it's a UPS after all, right?) but for some reason those cheaper batteries seem to develop one bad cell despite being treated well, and it goes unnoticed until the next time there is an outage.

Now again, in my experience, the 200Ah battery space tends to have better quality, it sort of rises above the cheap fray. But you cannot fit two 200hAh batteries into those trolleys, and as a result, people who buy those trolleys generally have a bad experience. Not because the trolley is bad, but just because of the neighbourhood it lives in... 🙂

 

Edited by plonkster

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16 hours ago, Darrenf said:

Right so after rabbit holing for a week I have decided to go with one of the 2 options and be done with it lol

So if you had the choice between the 2 which one would ya order? :)

As pointed out by @plonkster the are (should  be?) the same inverter to some extent (not sure if they differ in terms of MPPT rating etc. - too many variants to try and keep up with).

I would likely go with the Mecer branded just in terms of potential repair/backup (NOT from personal experience I assume mustek may have more options to repair/replace than geewiz might).

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Posted (edited)
3 hours ago, Darrenf said:

any suggestions on how maintain those batteries or any other suggestions?

 

1 hour ago, plonkster said:

My experience with this is that you have basically two groups of batteries. You can buy below 5k ZAR or above it. Now most people are going to buy the cheaper battery because they just spent 9k-10k for the inverter-trolley...

Treat them badly, eg discharging them too deeply, and you're looking at not even 6 months.

If you buy a good AGM battery though, and you treat them well, you could well be okay for 3 years or more. And by good I mean something like your Victron AGM or Gel batteries.

However, what happens to most people is that once load-shedding stops, you forget to look after the batteries, until the next time load-shedding starts. In an ideal world just keeping the batteries floated should be all you need to do (it's a UPS after all, right?)

This should probably become a new topic in the battery section but I suspect  lead acids are just not meant for what we have in 99% (arbitrary number) of our local load shedding solutions and scenarios. I want to look into it a bit more, unless someone knows the answer ( @plonkster, @Coulomb, @Chris Hobson .. who else?). If leaving out deep discharge/abuse and crap quality I wonder if "deep cycle" (AGM etc.) batteries actually offer any advantage over less exotic (less pricey?) types for "trolley load shedding" use? 

In essence you need a battery that is a UPS battery (happy to float for long without intervention) but when a fantactic 4 days of load shedding come around once every 2 months you need a deep cycle battery that is happy to charge/dischagre more frequently and at a fairly high rate. It looks like the AGM/GEL/general "deep cycle" batteries do no better when floating in terms of service life than less "exotic" types?  .... I came across a reference  (not exactly a peer reviewed journal I know) that if lead acids are routinely discharged no deeper than 5% they develop Lead Dioxide buildup which also cuts their life short... which is why I wonder about AGM's and floating.

So simplest answer is maybe, other than the usual appropriate voltages/C-rate/DOD etc,  maybe cycle your trolley with AGM's once a week?

Edited by introverter
typo..spelling etc.

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I think the best answer is to invest in a LiFePO4 battery. Yes, prices are still around 7.5k for each stored kWh, but your peak discharge is two to five times better than lead acid and it can cycle much deeper without affecting the cycle life that badly (so you can literally size it for your average load times 4 hours). That fits the load-shedding scenario much better than lead acid.

Lead acid actually works better off-grid or where they are used daily. Then you size it for the expected cycle life, your discharge rates are 10% or 15% of the capacity at most, cycle it to no more than 50% DoD, etc etc... all things that are a lot more conducive to longer battery life.

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Just now, plonkster said:

I think the best answer is to invest in a LiFePO4 battery.

Ag no man, that is cheating like saying the best fuel economy solution to your 5L V8 is to buy a Prius...😉 (unfortunately also my conclusion for our load shedding trolley scenarios).... but the people who just can't afford to push the budget to lithium are left a bit buggered (sure the guys selling batteries don't mind...).

Example of someone who through maybe a bit of bad luck/expensive school fees managed to get only 1 year (and almost no actual use) out of a set of omnipowers. He just needs a victron temp sense then I think he has added every blue accessory available to his (green) axpert to try and get a fair service life from his batteries but doesn't look promising.

The out of pocket cost on lithium is quite high and below 48V also seem very bad value for money (other than some "second life" or build your own options). 

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2 hours ago, introverter said:

Ag no man, that is cheating like saying the best fuel economy solution to your 5L V8 is to buy a Prius...😉 (unfortunately also my conclusion for our load shedding trolley scenarios).... but the people who just can't afford to push the budget to lithium are left a bit buggered (sure the guys selling batteries don't mind...).

Hahaha yes. But you can make a compromise. If you can trim the power requirements a bit, then for the same price as that trolley you can have this. Tht That ticks almost all the boxes, except it is a tad small. You could probably fit the essentials (some lights, an internet router, a television) into that 400W easily, but it is only going to last an hour if you do that. You could probably get a really long way with just 200W (again, if we're really talking ONLY essentials), but it still doesn't quite handle a 4-hour slot.

You could also look at BlueNova's drop-in replacements and stick those in your Axpert/Mecer trolley, but then you might as well use a 24V Pylontech battery (same price)... cause now we're talking >20k on the battery alone. Once you get to this point, you should start wondering if it is a good idea to spend that much money on a 24V battery and if you shouldn't rather shoot for 48V... and once you get to this point, you are way further down the rabbit hole than you planned on being 🙂

I'd say get the 24V trolley (or make your own) and stick two 100Ah OmniSolar batteries on it. That's going to set you back around 8k for the batteries and another 8k or so for the trolley/inverter+accessories. 16k-20k. Not a cheap game this...

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