Hi and thanks in advance

We are running:

3 x routers

1 x laptop charger (always on)

2 x DSTV decoders

2 x TVs (1 on 1 off)

Beginning February we started with 1 battery (120aH 12V deep cycle gel) and an Andowl 1200kW UPS inverter/charger. Despite intermittently claiming to be overloaded, this ran the appliances above for 2 hours. Mid April we added a second battery and got 4 hours (charging second battery independently with a smart charger. (Inverter charged 1 battery to 14.3V, smart charger the other to 13.3V))  Batteries held less and less. Inverter stopped working. Around start June we got a 2000kW Takealot inverter. Charging both batteries with smart charger to 13.3V we are getting 1 and a half hours until batteries read 10.5 or less.

What have we done or are we doing wrong please?

 Thanks again

 

15 hours ago, ayreon said:

Hi and thanks in advance

We are running:

3 x routers

1 x laptop charger (always on)

2 x DSTV decoders

2 x TVs (1 on 1 off)

Beginning February we started with 1 battery (120aH 12V deep cycle gel) and an Andowl 1200kW UPS inverter/charger. Despite intermittently claiming to be overloaded, this ran the appliances above for 2 hours. Mid April we added a second battery and got 4 hours (charging second battery independently with a smart charger. (Inverter charged 1 battery to 14.3V, smart charger the other to 13.3V))  Batteries held less and less. Inverter stopped working. Around start June we got a 2000kW Takealot inverter. Charging both batteries with smart charger to 13.3V we are getting 1 and a half hours until batteries read 10.5 or less.

What have we done or are we doing wrong please?

 Thanks again

 

These batteries should not be discharged lower than 11.8V under load or 12V with no load. They were over cycled due to LS nearly daily. 

Not sure if the takealot unit Can run on lithium. Provide the complete name and model and if a sticker on the side place it here. 

10.5V disconnect gives good time on battery power but kills the battery in a few months as you found out. 

Further the batteries should be charged to about 14.1V. The 13.3V via clever charger was also too low and contributed to early death due to being under charged all the time. 

Check how much power the TV uses. The 3 routers and laptop charger without TV should give about 7 hrs run time. 

Edited July 11, 20233 yr by Scorp007

41 minutes ago, Scorp007 said:

These batteries should not be discharged lower than 11.8V under load or 12V with no load. They were over cycled due to LS nearly daily. 

Totally agree. Everyone wants to get the maximum runtime, totally understandable, but that's the nature of lead acid. You just can't deeply discharge them more than a dozen times; "deep cycle" really just means that these are not starter batteries. But they still should not be discharged more than 50% depth of discharge, except a few times in their life. Lead acid is a really bad fit for regular load shedding, when used with default settings that assume very infrequent deep discharge, like once a year at the very most.

Edited July 11, 20233 yr by Coulomb

You charging batterys to float charge and so they not fully charged at that volts and so it  can take hours for them to reach full charge at 13.3v float only . 

You did not say what inverter you have but sounds like it is just an bench  inverter and not an sin wave hybrid inverter as you using an smart charger .

The problem with smart charger you can not set the bulk and float charge for the specific battery used and so you mite be undercharging or over charging your battery NOT good 

The problem with these normal cheaper bench inverter is you can not set the shut down volts so you over discharging your batterys NOT good  . 

In the end such an setup is going to cost a fortune on batterys or having to  constantly babying the system to prolong battery life .

If 12 v system is all you really need for the basics and load shedding solution then you get same nice hybrid  sinwave 1.8 kw inverter for around R4500 so allowing you to setup charge volts and shutdown volts for the type battery used . 

 

Hi and thank you so much.

 Current inverter and manual below.

Full setup

So moving forward

- what is the cheapest/fastest charger for these batteries?

- should/can the batteries be replaced with lithium (or other)? Please refer.

- what is a suitable inverter/battery setup for stage 6 load shedding for our needs (perhaps more specific than gmac’s greatly appreciate advice above)?

 Thank you for patience with novice. 

Regards

1 hour ago, ayreon said:

Hi and thank you so much.

 Current inverter and manual below.

Full setup

So moving forward

- what is the cheapest/fastest charger for these batteries?

- should/can the batteries be replaced with lithium (or other)? Please refer.

- what is a suitable inverter/battery setup for stage 6 load shedding for our needs (perhaps more specific than gmac’s greatly appreciate advice above)?

 Thank you for patience with novice. 

Regards

Just a few points. 

Based on what we know the battery has taken a knock that's why you only get 1.5hrs run time. 

Further we all want the fastest charger which if over about 18A will further shorten their life due to daily LS. Try and reduce your load as you have control over what you switch on. 

That 120Ah battery when new had 1440Wh of power up to totally discharged. To get a good life of over 18 months you should not use more than 720Wh before recharging. Not easy due to short periods that you can recharge before the next LS event. 

The 11.8-12V discharge level I mentioned will have to be implemented to save what you can save. 

Your current inverter should only cut out at about 10.5V being too low. 

I still rate this R100 voltmeter a good starting device to guide you when to reduce or switch off loads during LS. 

The next item will be a Victron battery protector to cut the battery off when reaching the 12V level. R900 is cheaper than replacing the battery every 6-9 months. 

May be share a close up picture of the charger you are using. 

Although the Telefunken has a 95W power supply it might draw 40-50W during operation. Thus for 4 hours it will use about 200Wh of power plus 15% due to losses from the inverter. 

 

Edited July 13, 20233 yr by Scorp007

On 2023/07/11 at 3:42 PM, Coulomb said:

You just can't deeply discharge them more than a dozen times; "deep cycle" really just means that these are not starter batteries. But they still should not be discharged more than 50% depth of discharge, except a few times in their life.

I think this is extremely important information. People generally think that "Deep Cycle" means you can do it all the time (I did in the beginning too), but it is really meant for emergency situations, like getting your boat to the harbor before dark or something like that.

Looking at your inverter  specs sheet shut down volts are battery killer volts.

On your setup,  no you can't replace your deep cycle  battery with lithium 

To go for lithium you will have to buy an charger that can charge lithium and they not cheap .

So my advices is save your self all the trouble of buying bits and pieces to make your system reliable and battery friendly and buy an hybrid inverter and if 12v setup is all you need then for around R10k you can buy an 12v hybrid inverter with 100ah lithium battery and you should be good then for years of more load shedding 

Edited July 13, 20233 yr by GMAC

On 2023/07/10 at 11:18 PM, ayreon said:

We are running:

3 x routers

1 x laptop charger (always on)

2 x DSTV decoders

2 x TVs (1 on 1 off)

This makes little sense.  Why 3x routers?  And why do you power 2x DSTV decoders if you only power one TV.  The first rule in L/S is to reduce your power consumption by as much as you can, especially if using lead-acids. 

Your Telefunken TV is an old LCD.  LCD, by definition, uses cold cathode fluorescent tube backlight technology.  New TVs use LED backlighting.  LED TVs consume approx. 50% less power.  Considering how super cheap a new TV is (in comparison to batteries) it would be a wise choice to replace your primary TV.

You have a 120Ah battery.  Even if the battery is only discharged to 50% SOC, that would mean you would need to replenish 60Ah.  That intelligent charger seems to be a PSA008 - it can charge at a maximum of 8A.  So it would take 60Ah / 8A = 7.5 hours. recharge time.  In reality it is even worse because the battery has losses (converted into heat).  You need to put more than 10Ah in if you want to draw 10Ah.
 

On 2023/07/10 at 11:18 PM, ayreon said:

What have we done or are we doing wrong please?

You weren't to know, but it's using a system based around lead-acid batteries. These don't do well in contemporary SA. I just looked at my load shedding schedule today. We had a 4.5 hour outage, with a second outage 3.5 hours later.

OK... so you batteries have got to get you through the 4.5 hours, then recharge in 3.5 hours, then start again. It's hard work. Lead acid batteries are a good option for situations in which they are maintained at full charge most of the time, and then must back up a load for occasional outages. Those are not the conditions we have in SA right now. 

Lithium batteries (especially the newest LiPO4) can be discharged more deeply, recharged more quickly, are much better suited to a situation where they are constantly being charged and discharged, and will generally last a lot longer.

Now... numbers are a big help. How much does the various items draw? Over a period of time? And peak consumption, which is usually on start up? Once we know those figures, then it's possible to size a system.

So that's the other thing you didn't do that a lot of folks don't do: homework. I only know about this stuff through the school of hard knock experience. Please don't feel bad about it.

Get those numbers, either using a device such as a kill-a-watt (theyr'e about R350), from the labelling on the appliances, or by dint of googling. 
 

@Modina's point is a good one. New appliances are very efficient, and it may help the cause to buy some new gear. This will cost you up front, but save in the long run (even when you're not shedding, they will draw less from the grid). Also read the manuals, there is probably an economy mode available to you that will reduce the device's power demand. 
 

1 hour ago, Bobster. said:

You weren't to know, but it's using a system based around lead-acid batteries. These don't do well in contemporary SA. I just looked at my load shedding schedule today. We had a 4.5 hour outage, with a second outage 3.5 hours later.

OK... so you batteries have got to get you through the 4.5 hours, then recharge in 3.5 hours, then start again. It's hard work. Lead acid batteries are a good option for situations in which they are maintained at full charge most of the time, and then must back up a load for occasional outages. Those are not the conditions we have in SA right now. 

Lithium batteries (especially the newest LiPO4) can be discharged more deeply, recharged more quickly, are much better suited to a situation where they are constantly being charged and discharged, and will generally last a lot longer.

Now... numbers are a big help. How much does the various items draw? Over a period of time? And peak consumption, which is usually on start up? Once we know those figures, then it's possible to size a system.

So that's the other thing you didn't do that a lot of folks don't do: homework. I only know about this stuff through the school of hard knock experience. Please don't feel bad about it.

Get those numbers, either using a device such as a kill-a-watt (theyr'e about R350), from the labelling on the appliances, or by dint of googling. 
 

@Modina's point is a good one. New appliances are very efficient, and it may help the cause to buy some new gear. This will cost you up front, but save in the long run (even when you're not shedding, they will draw less from the grid). Also read the manuals, there is probably an economy mode available to you that will reduce the device's power demand. 
 

As much as I agree on new equipment I can say I am cycling lead acids during the night for outside lights with a charger about the same size as the load. These batteries are over 2 years old and still getting a full charge during day time. These LA are used ex my Axpert prior to buying lithium. No problem with 4hrs LS during the night. 

I still belief the reason is because I cut my inverter from batteries at 12V with a Victron battery protector. 

Thus if my capacity of the LA drop they will just cut the load after less time but not damage them.

Not much one can do if the batteries have already being killed over a few months. As has been motioned even deep cycle LA don't like to be cycled to empty more than 12-20 times in their life time. 

@Scorp007  Yes, agreed.  But you get much cheaper battery under-voltage cut-out modules than the Victron.  The following two are under R200 and don't need a multimeter to adjust, as they contain their own volt meter.

https://www.robotics.org.za/XH-M609?search=battery protect
https://www.robotics.org.za/YX-X0001-1

The real problem is that with todays L/S, people unknowingly discharge at X-Ah and then want to use a X/2.... X/10 Ah charger and then wonder why the battery can't cope.  There is absolutely nothing wrong with using lead-acids if you have small loads such as a few LED lamps.  But if you want to run a 80W TV plus auxiliaries for 2 to 4 hours, that's when things start getting problematic.

As I have mentioned here in the past, I have a 24" HD-Ready LED Sinotec TV that can run straight from 12VDC and draws aprox 1A.  Firstly one can save on the inverter cost, one doesn't sit with the inverter losses and at a power rating of less than 15W that TV will run for many hours from a 100Ah LA battery and still remain within the 50% SOC.  Set-top boxes can normally also be run straight from a 12V battery or, to be on the safe side, connect a cheap buck/boost regulator.  The only down side is that it requires some very basic DIY capability, to make cables and own a multimeter, so as to be able to adjust the output voltage of the regulator.

Edited July 15, 20232 yr by Modina

1 hour ago, Modina said:

@Scorp007  Yes, agreed.  But you get much cheaper battery under-voltage cut-out modules than the Victron.  The following two are under R200 and don't need a multimeter to adjust, as they contain their own volt meter.

https://www.robotics.org.za/XH-M609?search=battery protect
https://www.robotics.org.za/YX-X0001-1

The real problem is that with todays L/S, people unknowingly discharge at X-Ah and then want to use a X/2.... X/10 Ah charger and then wonder why the battery can't cope.  There is absolutely nothing wrong with using lead-acids if you have small loads such as a few LED lamps.  But if you want to run a 80W TV plus auxiliaries for 2 to 4 hours, that's when things start getting problematic.

As I have mentioned here in the past, I have a 24" HD-Ready LED Sinotec TV that can run straight from 12VDC and draws aprox 1A.  Firstly one can save on the inverter cost, one doesn't sit with the inverter losses and at a power rating of less than 15W that TV will run for many hours from a 100Ah LA battery and still remain within the 50% SOC.  Set-top boxes can normally also be run straight from a 12V battery or, to be on the safe side, connect a cheap buck/boost regulator.  The only down side is that it requires some very basic DIY capability, to make cables and own a multimeter, so as to be able to adjust the output voltage of the regulator.

I accept there are other products as well but the Victron with models for 65A, 100A and 220A makes for a easy application on inverters. 

I have 2 of the type you mention and yes nothing wrong with it for low power apication or their battery charge control. 

I also like the Victron with cabled remote on/off switch as well as warning before the cut out. 

On these units you don't even need a multimeter as it has a single digit display to guide on the voltage used for cutout. 

Edited July 15, 20232 yr by Scorp007