Solar Install for parents please Help.

[Dejavus]

Hi All,­

 ­

I came across this forum by accident and ­it seems to be the best accident that has­ ever happened to me. The information I h­ave read on this forum in the last few da­ys has surpased everything I have read in­ the last 4 weeks!

 ­

I live in the UK but my parents’ lives in­ Nigeria and due to the erratic power sup­ply I am in the process of installing a P­V/Inverter battery to make their lives ea­sier to require as little maintainance as­ possible.

 ­

I have read so much in the last One month­ and have decided to settle down to the f­ollowing:

 ­

1 Axpert 3KVA Plus Hybrid  Inverter­

 ­

4 x US 2000 XC2 Flooded Lead-Acid 6V 240A­h or (alternative Trojan J185P-AC  12V 20­5Ah if there is any benefit in a 2 batter­y setup against the 4 battery setup)?

 ­

6 x 250Watt Mono Panels­

 ­

 ­

 ­

My questions are:­

 ­

1. I have heard that flooded battery need­s to be topped up roughly once a month an­d then equalize? would my Axpert inverter­ be able to do this equalization or do I ­need to get another device to do this.

 ­

2. The usage would mostly be for lighting­ (low energy bulbs + fan) so I intend to ­keep the DOD of the battery at a max of 5­0%, would there be a way to setup the Axp­ert inverter such that the inverter stops­ working once the battery DOD threshold h­as been exceeded?

 ­

3. From my lay man's point of view, I bel­ieve a 4 battery setup is better that a 2­ battery setup for the same 24V, please a­dvise if this is the case or not.

 ­

4. I also intend to feed the utility from­ the Power company into the inverter so t­hat the battery is harged whenever there ­is power supplied but nothing back to the­ grid, is there a setting available that ­requires very little maintainance except ­for the occassional battery top?

 ­

 ­

 ­

That would be all for now, I will post an­y further questions that come to mind, pl­ease feel free to make recommendations as­ approiprate.

 ­

Thanks in advance.­

 ­

dejavus­

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[Dejavus]

Hi. 

 

The Axpert isnot a true Hybrid. It can not puch power back to the grid. 

 

The SOC ofthe Acpert is not great. That is why I decided to write software that used the SOC of the Victron BMW to decide when to switch. 

Many thanks for your reply. I do not want to push Power back to the grid. I just want to recharge the batteries using grid as source when available.

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[Guest]

The best software is (Jdp) AICC that will do the job for you

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[Guest]

Many thanks for your reply. I do not want to push Power back to the grid. I just want to recharge the batteries using grid as source when available.

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Then the Axpert inverter is the right choice with jdp software to manage the inverter

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[Dejavus]

I ll appreciate any further advice re my questions above.

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[Guest]

With 4 batteries you need a balancer to balance the batterys

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[Guest]

The Axpert inveter will manage the 3 stage charging cycle

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[Dejavus]

2 hours ago, Manie said:

With 4 batteries you need a balancer to balance the batterys

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Would one balance be sufficient for this 6v x 4 battery setup? I can see one on ebay http://www.ebay.co.uk/itm/BALANCER-BATTERY-6V-Part-Number-CEQ6A-/390586040875?hash=item5af0be022b:g:M~8AAMXQatBScAz9 I assume I can purchase one using the connection on the right side.

[Guest]

Yes it shoul work.

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[Guest]

Dejavus, welcome.

If I was sitting in Europe, buying with Pounds a solution in Nigeria for my parents, I would not go for an Axpert. No, I would look at a 12/24v Victron Multiplus.

Reason: Victron is expensive in SA, not in Europe, and you need reliability.

Parts I would go for:
- Victron MPPT charge controller.
- 12/24v Victron Multiplus - you do not need 48v and the inverter can handle all your parents need.
- Victron BMV 702 battery monitor with temp gauge also, it gets hot there so temp info is invaluable.
- Trojan batteries with automatic water feeder. You dad just needs to keep the reservoir topped up. Rest is automated.
- Way to upload the data that you can view it, advise your parents.

Who can help?
- @plonkster can help with all that Victron can do as he is the resident expert on Victron to connect it all that it is plug and play, and on how to upload the data cost effectively.

And I will try and go for 20% DOD, instead of 50% DOD, the batts will last longer and they will have more of a safety margin in case of extended power outages, no sun.

 

BUT!!! Before you buy ANYTHING, what is the load they need powered, and for how long?
And what is the peak watts that needs to be catered for?

Why? Depending on the peak watts, load and run-time required, you could get down to 12v system, less panels, less batteries, making it all cheaper.

 

[___]

Official way, for now, is to buy the ccgx for monitoring. That's another 350 Euro. I tend to agree that if I was on the right side of the exchange rate, I'd go Victron, but I have to temper my fanboyness a bit.

You're right in second paragraph though. Start with needs analysis. Then decide if a smaller 24v system would do. If yes, consider the 3kva multiplus or even the 2kva compact. Look what after sales service is like in that country. I don't know Nigeria at all but I know Victron has some penetration in Africa, so just maybe that makes the difference :-

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[___]

Fwiw, my 1.6kva compact with a 200ah 24v battery and 900w solar works very well to keep the fridge and freezer powered and for general backup, and in an extreme case I would be able to survive... if there is sun. Based on that, in tropical Nigeria, it sounds like your plan will work.

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[Dejavus]

Sigh.

 

Where do I start probably first by thanking @TTT and @Plonkster for the time spent replying to my post.

I would very much love to go the Victron way however I have had to shell out on some less power  hungry electrical equipment in preparation for this project namely a new TV, previous one was 200W old sharp from 2007 to a 55W Sony, same goes for fridge freezer and fans hence my budget has depreciated to about 2K absolute maximum.

I thought of buying directly from the UK however the added cost of shipping has made it not a very good option plus warranty might be an issue if needed.

Hence my decision to go for the axpert plus my brother who is an eletcrical engineer can be summoned if required, he also currently uses a Gen/Grid battery powered solution himself. 

Aside of this project, I am also in the planning phase for a poultry farm which I intend to be completely an off grid solution.

 

 

[SilverNodashi]

On 6/18/2016 at 3:09 PM, The Terrible Triplett said:

Dejavus, welcome.

If I was sitting in Europe, buying with Pounds a solution in Nigeria for my parents, I would not go for an Axpert. No, I would look at a 12/24v Victron Multiplus.

Reason: Victron is expensive in SA, not in Europe, and you need reliability.

Parts I would go for:
- Victron MPPT charge controller.
- 12/24v Victron Multiplus - you do not need 48v and the inverter can handle all your parents need.
- Victron BMV 702 battery monitor with temp gauge also, it gets hot there so temp info is invaluable.
- Trojan batteries with automatic water feeder. You dad just needs to keep the reservoir topped up. Rest is automated.
- Way to upload the data that you can view it, advise your parents.

Who can help?
- @plonkster can help with all that Victron can do as he is the resident expert on Victron to connect it all that it is plug and play, and on how to upload the data cost effectively.

And I will try and go for 20% DOD, instead of 50% DOD, the batts will last longer and they will have more of a safety margin in case of extended power outages, no sun.

 

BUT!!! Before you buy ANYTHING, what is the load they need powered, and for how long?
And what is the peak watts that needs to be catered for?

Why? Depending on the peak watts, load and run-time required, you could get down to 12v system, less panels, less batteries, making it all cheaper.

 

Keep in mind, on a 12V system you need thicker cables to carry the same joules (i.e. Watt = Volt * Amp). To run a 1000W load, as example, off 12V you need 83A! It's only 42A over 24V. Then as your batteries are charged you need a few Ampere less, and a few more as the batteries run flat, i.e. 1000W = 90A / 11V or 45A/22V. 

Then, the more Ampere you withdraw from the battery the quicker it drains, not not linearly. Look at Pheukert's law. Simply put, the less strain you put on your batteries, the longer they will last and the longer they will run. 

On your questions: 

 

1. Flooded batteries need maintenance, yes, but if you are up to it (or, rather, if your parents are prepared to follow the maintenance procedures), they could easily outlast any battery for years to come. And you will gain back your investment after a few years. 

2. If there's no eskom backup, not really. Perpahs you could use the dry contacts to switch off a contactor in the DB board, and thus cutting the power off. 

3.It all depends on you / your budget / your backup needs. 2 x 12V/200Ah  = 24V/200Ah. 4x 12V/100Ah = 24V/200Ah. 4x 12V/200Ah = 24v/400Ah. More batteries equate using more cable, and could lead to more failure as well. If you need 4+ batteries, make sure they're from the same batch / age. Don't mix old and new batteries.

4. Yup. It's automatic Most inverter brands have this option. IF you have this option, you don't need to worry about Point #2, unless there's frequent power failures at night and your battery bank is too small to cope with the load. 
 

 

 

[Guest]

I just want to clarify 12/24/48v logic, for what SilverNoashi says above is 100% true IF you use 1000w on a 12 battery bank for extended periods ... not feasible at all.

But that is not what I said?

On 6/18/2016 at 3:09 PM, The Terrible Triplett said:

BUT!!! Before you buy ANYTHING, what is the load they need powered, and for how long?
And what is the peak watts that needs to be catered for?

Why? Depending on the peak watts, load and run-time required, you could get down to 12v system, less panels, less batteries, making it all cheaper.

 

I worked on, as my parent live with us, that a elderly couple who have very efficient devices, will peak at well below 1000w (managed off course), with an average load of wot 30watts per hour at night, maybe 200w with lights and TV on for 2-4 hours, using the highest feasible AH batteries to ensure 20%DOD resulting in less batteries, less cable and less maintenance, the above all pure speculation obviously, but it makes a case for a 12 or 24v system being cheaper.

A 48v system has a lot of benefits, but may be an overkill here and a little fact that only really surfaces, is when that first replacement is required of a 48v battery bank. That is when you sit up very straight when spending double if you needed 24v or tripple if a 12v system could have done the exact same job, because of the load requirements.

 

What is the load they need powered, for how long and what are the peak watts that needs to be catered for? 
Until that is known, we cannot just say that 48v is the one stop solution to every single solar system, can we?

So give all the options, then get the facts in. It can make a huge difference, either way. 

Any case, use it, don't, no stress.

 

Ps. I did find this quite ... interesting. 

On 6/19/2016 at 1:25 PM, Dejavus said:

... go for the Axpert plus my brother who is an electrical engineer can be summoned if required, ...

I did consider that the blue stuff gets setup before shipping, by an expert, to become plug and play, but never did I worry about how to fix it once installed. 

[viper_za]

3 minutes ago, The Terrible Triplett said:

load of wot 30watts per hour at night, maybe 200w with lights and TV on for 2-4 hours

He said a fridge and freezer also. For this I would still say 48v as I take my bank down to 80-85% (48v 225AH bank) running basically the same equipment every night

[Dejavus]

1 hour ago, SilverNodashi said:

Keep in mind, on a 12V system you need thicker cables to carry the same joules (i.e. Watt = Volt * Amp). To run a 1000W load, as example, off 12V you need 83A! It's only 42A over 24V. Then as your batteries are charged you need a few Ampere less, and a few more as the batteries run flat, i.e. 1000W = 90A / 11V or 45A/22V. 

Then, the more Ampere you withdraw from the battery the quicker it drains, not not linearly. Look at Pheukert's law. Simply put, the less strain you put on your batteries, the longer they will last and the longer they will run. 

On your questions: 

 

1. Flooded batteries need maintenance, yes, but if you are up to it (or, rather, if your parents are prepared to follow the maintenance procedures), they could easily outlast any battery for years to come. And you will gain back your investment after a few years. 

2. If there's no eskom backup, not really. Perpahs you could use the dry contacts to switch off a contactor in the DB board, and thus cutting the power off. 

3.It all depends on you / your budget / your backup needs. 2 x 12V/200Ah  = 24V/200Ah. 4x 12V/100Ah = 24V/200Ah. 4x 12V/200Ah = 24v/400Ah. More batteries equate using more cable, and could lead to more failure as well. If you need 4+ batteries, make sure they're from the same batch / age. Don't mix old and new batteries.

4. Yup. It's automatic Most inverter brands have this option. IF you have this option, you don't need to worry about Point #2, unless there's frequent power failures at night and your battery bank is too small to cope with the load. 
 

 

 

 

Thanks once again for taking the time to reply. I believe my Dad should be able to follow the maintenance procedure, He is usually religious about this kind of things so that's good.

Eskom = (PHCN in Nigeria) is very unreliable but will be wired as backup for usage and also to charge the battery if required as well.

Reason why I asked the question on the battery was to determine if there are any benefits to adopting either 4 or 2 setup but like you pointed out, more cables and higher potential of failure.  Overall thanks for your time.

53 minutes ago, The Terrible Triplett said:

I just want to clarify 12/24/48v logic, for what SilverNoashi says above is 100% true IF you use 1000w on a 12 battery bank for extended periods ... not feasible at all.

But that is not what I said?

 

I worked on, as my parent live with us, that a elderly couple who have very efficient devices, will peak at well below 1000w (managed off course), with an average load of wot 30watts per hour at night, maybe 200w with lights and TV on for 2-4 hours, using the highest feasible AH batteries to ensure 20%DOD resulting in less batteries, less cable and less maintenance, the above all pure speculation obviously, but it makes a case for a 12 or 24v system being cheaper.

A 48v system has a lot of benefits, but may be an overkill here and a little fact that only really surfaces, is when that first replacement is required of a 48v battery bank. That is when you sit up very straight when spending double if you needed 24v or tripple if a 12v system could have done the exact same job, because of the load requirements.

 

What is the load they need powered, for how long and what are the peak watts that needs to be catered for? 
Until that is known, we cannot just say that 48v is the one stop solution to every single solar system, can we?

So give all the options, then get the facts in. It can make a huge difference, either way. 

Any case, use it, don't, no stress.

 

Ps. I did find this quite ... interesting. 

I did consider that the blue stuff gets setup before shipping, by an expert, to become plug and play, but never did I worry about how to fix it once installed. 

 

Like I said I have spent some sizeable amount of money on new TV and Freezer purposely to take the overnight load down as much as possible. I also intend to install a timer switch for switching the freezer and fridge off in the evening when the sun is down for them to start again in the morning when the sun is out in order to reduce the overnight load to possibly lights and maybe a small fan.

 

PS: I mentioned my brother as he will sure knows better than my dad when it comes to electrical wiring and reading and understanding whatever is displayed on the control panels, he might not be able to fix it, but sure knows. :-) 

47 minutes ago, viper_za said:

He said a fridge and freezer also. For this I would still say 48v as I take my bank down to 80-85% (48v 225AH bank) running basically the same equipment every night

I intend to get a timer switch to make these work only during the day and off at night to possibly reduce the DOD drastically at night.

[SilverNodashi]

3 minutes ago, Dejavus said:

Thanks once again for taking the time to reply. I believe my Dad should be able to follow the maintenance procedure, He is usually religious about this kind of things so that's good.

Eskom = (PHCN in Nigeria) is very unreliable but will be wired as backup for usage and also to charge the battery if required as well.

Reason why I asked the question on the battery was to determine if there are any benefits to adopting either 4 or 2 setup but like you pointed out, more cables and higher potential of failure.  Overall thanks for your time.

Like I said I have spent some sizeable amount of money on new TV and Freezer purposely to take the overnight load down as much as possible. I also intend to install a timer switch for switching the freezer and fridge off in the evening when the sun is down for them to start again in the morning when the sun is out in order to reduce the overnight load to possibly lights and maybe a small fan.

 

PS: I mentioned my brother as he will sure knows better than my dad when it comes to electrical wiring and reading and understanding whatever is displayed on the control panels, he might not be able to fix it, but sure knows. :-) 

I intend to get a timer switch to make these work only during the day and off at night to possibly reduce the DOD drastically at night.

More batteries doesn't necessarily mean more problems. If you're looking at using flooded batteries, you'll either use 2V or 6V cells in any case. I have 16x 6V batteries in my bank, on 48V system

Don't put the fridge on a timer, been there, done that, lost enough food to be content with 100W/hr during the night  As long as the fridge is in a cool place so it doesn't operate too much at night. And new fridges consume a lot less power than older ones. 

[SilverNodashi]

1 hour ago, viper_za said:

He said a fridge and freezer also. For this I would still say 48v as I take my bank down to 80-85% (48v 225AH bank) running basically the same equipment every night

A 48V system would be much more efficient as a 12V or 24V, but if he only needs a couple hundred watt it should be fine?

[Guest]

1 hour ago, viper_za said:

He said a fridge and freezer also. For this I would still say 48v as I take my bank down to 80-85% (48v 225AH bank) running basically the same equipment every night

Nope, I disagree.

Dejavus, what no-one has said here, is the following:

You said the usage was, and I take if from above posts::
Usage would mostly be for lighting (low energy bulbs) - wot, 20 watts?
TV - 55W Sony
Efficient Fridge/ freezer - wot 255kWh per year?
Fans?

Assuming the load is:
Lights - total 100w on for 6 hours.
TV - 55 watt on for 6 hours
Fridge Freezer, 255kWh per year on for 24 hours.
Fan - 50w on for 24 hours

The sums for a 24v system with 2 days backup - no sun - you would need:
For 50% DOD: 450ah bank - 8 x 225ah T105RE's batteries or 4 x 370ah Trojan.
For 20% DOD: 1480ah bank - 16 x 370ah L16RE-B.

For a 48v system, 20% DOD, you also need 16 x 370ah for a 740ah bank, or 24 x 225ah batteries - not a CHANCE!!!

To charge the above, min of 4 x 200w 24v panels with average of 5.5 hours per day of good sunlight. That is just to recharge.

Ps. I did this quick ... we just need to check the maths!!!

What am I missing?

EDIT: Max inverter needed, is 218w average, so a 1300w inverter SHOULD work perfectly if the fridge/freezer starts up simultaneously, being very efficient due to low startup current.

 

 

[Guest]

Here are the calcs ... sharing is caring, as Plonkster says.

Off-Grid - Master - Solar-Panel-Design1.1.15.xlsx

EDIT: And cables, use 35mm2 or even better, 50mm2 between the batts, with fuses, then there are even less worries. 

[Louw]

TTT - My 2 cents - If you bargain for 2 days of no sunshine you actually need to plan for 2.5 days worth of battery life,

Take the weekend in CPT - No/limited sunshine on Saturday and Sunday.  So you had to run on batteries from Friday Sunset to Monday Sunrise - ie. 2.5 days! 

[Guest]

7 minutes ago, Louw said:

TTT - My 2 cents - If you bargain for 2 days of no sunshine you actually need to plan for 2.5 days worth of battery life,

Take the weekend in CPT - No/limited sunshine on Saturday and Sunday.  So you had to run on batteries from Friday Sunset to Monday Sunrise - ie. 2.5 days! 

Two good cents. You are right, but we are talking Nigeria here, and if I was totally reliant on solar, I would have started a generator by day 2, cheaper than more batteries for the few problem days in a row, than more panels and batteries. 

 

Dejavus, you where very wise, FIRST reduce, then solarize!

And with 2 older people, who tend to be more disciplined and respect more the little joys of having the convenience of power, the solution is simple.

And as I said before, if these where my parent, I would never put in an Axpert. And I will invest in a proper separate MPPT controller. 

Those are the two things that can really cause you more grief and spoil it for you, causing them some real frustrations. The MPPT controllers I am thinking of, by default, can be set to 12v/24v/48v settings, so you are not held to ransome if you need more panels later, or change the system battery volts.

And IF the 24v inverter turns out to be too light because the load increased for whatever reason, then it becomes a light / TV power source, with a separate larger pure inverter to power the then larger loads when needed.

All the above giving you more room to manuevre, on a thigh budget, yet not compromising on quality or convenience.

But, I suspect your parents will reduce even more.

And do not go for the Axpert. There have been problems surfacing on this site lately around them.

[Guest]

Another though.

If you where to buy with your pounds, by waiting for the right exchange rate, the batteries and all that in South Africa, you could score a bit more ito savings.

Even more if someone here was to sell it to you at near SA cost price. 

Then all that is left is to get it to Nigeria, from SA, as cheap and reliably as possible, with insurance to cover the risk.

Ag, what do I know. 

[SilverNodashi]

1 hour ago, Louw said:

TTT - My 2 cents - If you bargain for 2 days of no sunshine you actually need to plan for 2.5 days worth of battery life,

Take the weekend in CPT - No/limited sunshine on Saturday and Sunday.  So you had to run on batteries from Friday Sunset to Monday Sunrise - ie. 2.5 days! 

Agreed. And add what you use during the day to your PV system. We use more power during the day than at night, often 4x more. So our PV system is 2.5x what the battery bank can hold, works out fine at this stage, but we're short on energy, on cloudy days. I could add another 4 panels to compensate but don't have the roof space for it, close to the existing battery bank