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Best 48v 16s bms and active balancer please?

That is going to be a function of the charging system programming to extend the time. Often there is a manual adjustment.
How can it extend the time of the BMS is tripping out with cell over voltage? I think reducing the charge voltage and/or current is probably what you're wanting to do?
 
How can it extend the time of the BMS is tripping out with cell over voltage? I think reducing the charge voltage and/or current is probably what you're wanting to do?
Reduce the voltage until the cells are balanced. I assume the total battery voltage is known when the cell over volt happens. Reset to 100mV lower and let it run at least a couple hours per day. Hopefully the active balancer will get things straight and the voltage can be increased each week.

I hope there is not some other issue with a cell or a connection that is throwing off the balance. This will be discovered as this unfolds.
 
Reduce the voltage until the cells are balanced. I assume the total battery voltage is known when the cell over volt happens. Reset to 100mV lower and let it run at least a couple hours per day. Hopefully the active balancer will get things straight and the voltage can be increased each week.

I hope there is not some other issue with a cell or a connection that is throwing off the balance. This will be discovered as this unfolds.
I that's what I said. You made it sound like adjusting the absorption time setting in the charger settings was going to help.
 
I have 10 batteries, 132kWh+. Off-grid. My one JK is the best BMS. During testing, 4 out of 10 can be charged over 55.5V without a cell ov and 200-300mV difference. It's no problem because my max absorption is 55V and max float is 53.7V. I adjust them depending on weather forecast.
 
I that's what I said. You made it sound like adjusting the absorption time setting in the charger settings was going to help.
Mine is set at 10 minutes and would be too short for an active balancer to work the balance at the top end. If already set at a couple hours probably fine. If the voltage cut off has to be set low like 54.4 maybe 4 to 6+ hours is better.
 
Mine is set at 10 minutes and would be too short for an active balancer to work the balance at the top end. If already set at a couple hours probably fine. If the voltage cut off has to be set low like 54.4 maybe 4 to 6+ hours is better.
A lot of controllers dint have adjustable time or tail current to end absorption. On a lithium battery adjusting the voltage will have the same effect.
 
Agree with squowse. Set your charge controller to a voltage that won't trip the BMS. This will give a chance for the balancer to do its job.
 
I don't think an active balancer will be able to help you with that extra 20A charge current. It would need to be shedding 20A average from each of the 2 cells, So 40A. And they only operate 50% of the time so 80A balancing current required. With those cells I think you will have to accept lower charge current or reduced capacity. How much is the capacity reduced by? The cells are virtually full at 3.29 resting voltage.
From what iv been instructed 3.29 is storage voltage. 3.48ish is full .
Reducing my capacity is not a option. I live off grid so my backup is critical. I run a 220vac well for water.
I can't charge past 54.2 without a cell reaching 3.65 and the others at 3.38ish. Most the capacity is 3.4 area for these sells.
An active balancer has to help a bit.
 
54.2 volts can be held all day until some balancing occurs and voltage can be increased.
 
From what iv been instructed 3.29 is storage voltage. 3.48ish is full .
Reducing my capacity is not a option. I live off grid so my backup is critical. I run a 220vac well for water.
I can't charge past 54.2 without a cell reaching 3.65 and the others at 3.38ish. Most the capacity is 3.4 area for these sells.
An active balancer has to help a bit.
I charge at 3.475 then it settles to 3.3
 
I charge at 3.475 then it settles to 3.3
What cells are you running. I'd get the same when my cells are balanced. I'd hold for 2 days no sun winter time in michigan at 53.1v.
3.29 is what I get while charging. I can tell you tomorrow what resting voltage is.
When the cells hit 3.4v it takes a while to go above it while charging.
Right now im running 2p16s 280ah so called Kenhang grade cells. But that's not what they are.
I have 16 more 271 catl cells that test at 283ah I'm considering throwing in the pack. Running 3p16s.
Do you recommend the capacitor style balancers? Iv heard the capacitors like to pop on them.
 
I charge at 3.475 then it settles to 3.3
I'm also going to try this extra bms I have. See if this one is not working right. I have it set to 560ah with my 2p16s bank. But the S.O.C. percentage never go's above 50% . So It could also be the BMS itself giving the issue if something isn't right in the software or hardware.
My growatt when charging with generator is set to 40amps. But the BMS claims to hit 70 to 80 Amp often with no solar assistance.
When I check with a meter I never see past 45amps. Kinda crazy.
 
Yes they seem fine when top balancing. But a week of usage and they start to drift. M6 studs. What torque do you recommend ?

If you have laser welded M6 studs and not drilled and tapped holes in the cells, the spec I have seen is 78 in-lbs. of torque. I torqued my cells with welded studs to 70 in-lbs. with a torque wrench with no problems.

As was stated a loose connection(s) can cause problems with cell imbalance. I clean all connections thoroughly with 99.9% isopropyl alcohol and then tighten to 70 in-lbs. on the cells.
 
Do you recommend the capacitor style balancers? Iv heard the capacitors like to pop on them.
My 4s capacitors have been fine going almost a year. Trouble with the capacitors is the current will be much smaller than rated as the cells get close in voltage. To get the 5a rating the differential needs to be close to 500mV. Closer to 1 amp at 100mV delta.

Look again at the NEEY balancer link above. I understand this one moves 4 amps continuous.
 
If you have laser welded M6 studs and not drilled and tapped holes in the cells, the spec I have seen is 78 in-lbs. of torque. I torqued my cells with welded studs to 70 in-lbs. with a torque wrench with no problems.

As was stated a loose connection(s) can cause problems with cell imbalance. I clean all connections thoroughly with 99.9% isopropyl alcohol and then tighten to 70 in-lbs. on the cells.
I believe there welded. At least that's what I was told. I'll look closer and report back.
 
My 4s capacitors have been fine going almost a year. Trouble with the capacitors is the current will be much smaller than rated as the cells get close in voltage. To get the 5a rating the differential needs to be close to 500mV. Closer to 1 amp at 100mV delta.

Look again at the NEEY balancer link above. I understand this one moves 4 amps continuous.
I'll take a look. Is that one reliable ?
 
I don't have a NEEY but I would if I was running more voltage. Put "NEEY" in the search to get some additional reading.
 
Personally, if your Daly (real or knock-off) is doing it's job as a BMS I'd be tempted to keep it and add a high-current (5A) flying capacitor balancer.

Plenty on the market from multiple Chinese sellers, seem to be much of a muchness.

Flying-capacitor balancers can transfer charge between any pair of cells (not just adjacent cells) so you don't throw away energy, just move it.

We have one of these looking after our very worn ex-golf cart cells. https://www.lazada.co.th//products/i2547693090-s9060712387.html but there are many on AliExpress and the like.

Note:- For 16S just leave the 17th wire unconnected.

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I have a lifepo4 48v ...360ah battery bank with a 2amp JK BMS, I'm thinking of installing a high-current (5A) flying capacitor balancer. I've read that it can balance them faster... could you tell me if what I want to do is right? .....Thank you
 
I have a lifepo4 48v ...360ah battery bank with a 2amp JK BMS, I'm thinking of installing a high-current (5A) flying capacitor balancer. I've read that it can balance them faster... could you tell me if what I want to do is right? .....Thank you

How out of balance do your cells get?

You would certainly get a faster balance but whether it's actually worth the expense ...

Our cells are very worn and wouldn't balance at all using the built in balance on our Seplos BMS. Enter Mr Flying Capacitor, I leave it running all the time and the cells rarely get more than 150mV adrift and if one does get a bit high the BMS throttles the charge current (via inverter coms) which gives the balancer a chance.
 
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