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What controllers?
#1
So I have a simple 5kw solar array. When I got my inverter last year I specifically told the salesman I was going to add batteries later. He sold me a SunnyBoy 5.0 us. I installed the whole system myself, as you do. And after it was all in and humming along for 6 months I went through the manual looking for what module I would need to buy to add batteries. Nothing, you can't. So I call up Alt E store where I bought it and say I need battery charge controller for my system. They had several suggestions for 48v 5000w systems and then I mentioned I was building my own powerwall. The sky cracked open and cthulu belched forth fire and death. The tech almost immediately blew me off the phone. Suggested I call a controller manufacturer to plead forgiveness. When I did they threw their hands up and said it can't be done because the bms has to talk to the controller otherwise the batteries explode. My question was, how the hell do dumb lead acid batteries talk then.
Basically it's a liability thing. Now I have seen your videos for over 2 years and it's obvious yours work, and have seen like 5 systems from other tubers working as well.

Tldr: what do I need to integrate these batteries into my system so I can have it run my home at night until it gets low and have to go back on grid.
Thanks
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#2
(02-14-2019, 07:10 PM)DIYResto Wrote: So I have a simple 5kw solar array. When I got my inverter last year I specifically told the salesman I was going to add batteries later. He sold me a SunnyBoy 5.0 us. I installed the whole system myself, as you do. And after it was all in and humming along for 6 months I went through the manual looking for what module I would need to buy to add batteries. Nothing, you can't. So I call up Alt E store where I bought it and say I need battery charge controller for my system. They had several suggestions for 48v 5000w systems and then I mentioned I was building my own powerwall. The sky cracked open and cthulu belched forth fire and death. The tech almost immediately blew me off the phone. Suggested I call a controller manufacturer to plead forgiveness. When I did they threw their hands up and said it can't be done because the bms has to talk to the controller otherwise the batteries explode. My question was, how the hell do dumb lead acid batteries talk then.
Basically it's a liability thing. Now I have seen your videos for over 2 years and it's obvious yours work, and have seen like 5 systems from other tubers working as well.

Tldr: what do I need to integrate these batteries into my system so I can have it run my home at night until it gets low and have to go back on grid.
Thanks


FYI - Received a similar response when I dealt with Alte and told them I was using Chevy Volt batteries. In someways we are breaking new ground but in other ways this has been proven already - ex. GM VOLT UPS - 6 years ago  I can't speak to 18650s but I can speak for my experience with the Volt. After 8 months, bullet proof. 2 whole 2011 Gen1 car packs, 32kwh and no issues. Purchased BMS system but have been holding off for now given everything is in balance, biggest delta has been 10mv (3.76 vs. 3.77). I think the system naturally balances given low solar demands vs. the intended purpose (high drain and high charge life). 
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#3
(02-14-2019, 08:18 PM)Solardad Wrote:
(02-14-2019, 07:10 PM)DIYResto Wrote: So I have a simple 5kw solar array. When I got my inverter last year I specifically told the salesman I was going to add batteries later. He sold me a SunnyBoy 5.0 us. I installed the whole system myself, as you do. And after it was all in and humming along for 6 months I went through the manual looking for what module I would need to buy to add batteries. Nothing, you can't. So I call up Alt E store where I bought it and say I need battery charge controller for my system. They had several suggestions for 48v 5000w systems and then I mentioned I was building my own powerwall. The sky cracked open and cthulu belched forth fire and death. The tech almost immediately blew me off the phone. Suggested I call a controller manufacturer to plead forgiveness. When I did they threw their hands up and said it can't be done because the bms has to talk to the controller otherwise the batteries explode. My question was, how the hell do dumb lead acid batteries talk then.
Basically it's a liability thing. Now I have seen your videos for over 2 years and it's obvious yours work, and have seen like 5 systems from other tubers working as well.

Tldr: what do I need to integrate these batteries into my system so I can have it run my home at night until it gets low and have to go back on grid.
Thanks


FYI - Received a similar response when I dealt with Alte and told them I was using Chevy Volt batteries. In someways we are breaking new ground but in other ways this has been proven already - ex. GM VOLT UPS - 6 years ago  I can't speak to 18650s but I can speak for my experience with the Volt. After 8 months, bullet proof. 2 whole 2011 Gen1 car packs, 32kwh and no issues. Purchased BMS system but have been holding off for now given everything is in balance, biggest delta has been 10mv (3.76 vs. 3.77). I think the system naturally balances given low solar demands vs. the intended purpose (high drain and high charge life). 
My thing is as far as the charger is concerned the batteries are stupid. These powerwall batteries will have their own BMS which should balance the load. I dont think they understand that. In their minds (from my discussions with them) they expect that each cell in the battery reports back to the charge controller. That seems really strange while Lead Acid batteries couldnt be assed to do that at all. A plate could be bad in a lead acid battery as much as a cell bad in the power wall.
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#4
Just FYI the only difference why we don't have to manually balance lead acid batteries, is because they self balance by charging, because if a cell gets nearly full the resistance will drop and the other cells get more charge. But I get what you mean some people stop listening, when they think you're wrong...
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#5
(02-14-2019, 10:18 PM)LEDSchlucker Wrote: Just FYI the only difference why we don't have to manually balance lead acid batteries, is because they self balance by charging, because if a cell gets nearly full the resistance will drop and the other cells get more charge. But I get what you mean some people stop listening, when they think you're wrong...
The BMS we attach to the groups do the same thing right, that plus the fuses add a layer of protection. It should all be self balancing if I am not mistaken?
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#6
Lead acid do self balancing, Lithium cells not!
I'm not sure if you meant it that way, but for Lithium cells you have to use a BMS with balancing function or a separate balancer.
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#7
(02-15-2019, 12:12 AM)LEDSchlucker Wrote: Lead acid do self balancing, Lithium cells not!
I'm not sure if you meant it that way, but for Lithium cells you have to use a BMS with balancing function or a separate balancer.

Ya I mentioned BMS in the post above yours. 

So any charge controller would work?
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#8
So any charge controller would work?

If the battery pack is in perfect balance any charge controller will work. The controller uses overall voltage to monitor the battery and when to switch to float/stop charging. 
If the battery is out of balance, the bms will trigger the charging to stop early, and you might not get a full charge. On my battery it always  goes out of balance when charging at high amps, I use active balancers to compensate, they work for me.

The only controller I know that actually monitors balancing is the electrodacus controller, theres a thread on this site about it and the designer answers any questions you might have. The electrodacus website shows it being used on large systems, so it will probably work on your system.
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#9
(02-15-2019, 02:41 AM)jonyjoe505 Wrote: So any charge controller would work?

If the battery pack is in perfect balance any charge controller will work. The controller uses overall voltage to monitor the battery and when to switch to float/stop charging. 
If the battery is out of balance, the bms will trigger the charging to stop early, and you might not get a full charge. On my battery it always  goes out of balance when charging at high amps, I use active balancers to compensate, they work for me.

The only controller I know that actually monitors balancing is the electrodacus controller, theres a thread on this site about it and the designer answers any questions you might have. The electrodacus website shows it being used on large systems, so it will probably work on your system.

Thanks JonyJoe! That is what I was looking for something to get me pointed in the right direction. I will look for that thread later on today. Heart
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#10
The big difference between LA ability to self balance compare to a BMS on a lithium is that a LA can take a higher current without issues and they balance faster meanwhile you easily saturate the max current a BMS can take before it cant keep up with charge.

Aka a BMS can take for instance 500mA and above that the voltage will raise meanwhile a LA battery just regulates it rather fast. Thats why lithium batteries need disconnect function and preferable proper feedback to the charger to regulate it towards the end.

Unfortunately not many are aware of this and how it works.

Batrium for instance have this function built in and can manage several inverters and chargers. Victron also have support for this on some models.
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