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Top balancing problems?

Lucky360

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Nov 11, 2020
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Hello, I am top balancing my lishen 272 cells that I received. I set my power supply to 3.65 volts and 10 amps. Right now my power supply is in constant voltage mode at 3.65 volts and 9.25 current and current is slowly dropping. I thought it would turn to constant current mode quickly. Is something wrong or will it turn to constant current later? Thanks
 
It sounds like your power supply is doing what you want it to do.
The cells are absorbing the charge.
When the current get close to zero you should shut off the power supply.
The power supply might shut itself off when current gets to zero. But if it doesn't you need to turn it off.
 
Thanks for the reply, I noticed that if I touched the banana plugs going to the power supply the current dropped one full amp. I cut off the banana plugs and put leads on the ends I am now at a full 10 amps and the power supply went in constant current mode so ya that’s great. So right now the voltage is 3.53 and the current is 10.00 amps. Crazy how much resistance banana plugs had. Never worked with a power supply before so not sure why a bad connection would not let the power supply go into constant current mode. I guess it’s working correctly.
 
Thanks for the reply, I noticed that if I touched the banana plugs going to the power supply the current dropped one full amp. I cut off the banana plugs and put leads on the ends I am now at a full 10 amps and the power supply went in constant current mode so ya that’s great. So right now the voltage is 3.53 and the current is 10.00 amps. Crazy how much resistance banana plugs had. Never worked with a power supply before so not sure why a bad connection would not let the power supply go into constant current mode. I guess it’s working correctly.
Good move switching to better connectors.
I bet it will taper the amps again very soon.

What power supply are you using?
 
Iam using a tacklife 10amp, it had good reviews on Amazon. Never using a power supply is a little daunting don’t want to mess anything up lol.
 
Iam using a tacklife 10amp, it had good reviews on Amazon. Never using a power supply is a little daunting don’t want to mess anything up lol.
What size battery?
It takes a long time to taper all the way to zero.
It is probably best to check it at least every couple hours and turn it off when you sleep.
Some power supplies do strange things when they finish tapering the current.
 
They are lishen 272, right now batteries are at 3.304 volts started at 3.257 volts. Power supply is still at 3.53 volts and 10 amps. That is a good idea of turning it off when asleep.
 
Im doing the same but i have the voltage set to 3.65 Been connected for 28 hours but current not dropping should i see a drop in that time? My wife said it actually went up was at 3.9 now its at 4.1 does this sound like theres an issue or is this normal?
 
Im doing the same but i have the voltage set to 3.65 Been connected for 28 hours but current not dropping should i see a drop in that time? My wife said it actually went up was at 3.9 now its at 4.1 does this sound like theres an issue or is this normal?
No that sounds like disaster for lifepo4 cells.
If these are lifepo4 cells stop charging immediately and discharge those cells to <3.4 volts.
3.65 volts is the maximum voltage for lifepo4.
 
Sorry i need to clarify, the amps is what im referring to not changing or possible going up. If i understand this right when i set the charger to 3.65 Im waiting for the amps to drop to know it is complete - correct?
 
Sorry i need to clarify, the amps is what im referring to not changing or possible going up. If i understand this right when i set the charger to 3.65 Im waiting for the amps to drop to know it is complete - correct?
Ok lets do the math.
Lets say you have 16 280ah cells in parralel.
Most cells come ~50% charged so.

16 cells * 280 amp hours * .5 state of charge / 4 amps = 560 hours.
You can adjust the math if your cells are not 280 amp hours.
 
Im doing the same but i have the voltage set to 3.65 Been connected for 28 hours but current not dropping should i see a drop in that time? My wife said it actually went up was at 3.9 now its at 4.1 does this sound like theres an issue or is this normal?
Sounds like you adjusted the voltage with the leads connected to the battery .... never do that or you will risk ruining your cells.
Always ...... adjust the voltage then connect the leads.
 
Is there any way to top balance using solar panels and the solar charger with a sbms ? My 5 amp dc power supply will take months to top balance at the present rate.
 
Is there any way to top balance using solar panels and the solar charger with a sbms ? My 5 amp dc power supply will take months to top balance at the present rate.
Read this and use your solar charge controller for the serial part of the process.


Since the sun is less determinant you will have to be more vigilant.
 
Hi
I have a question 12 volt 4s 100 AMP top balancing
Are my cells balanced ? , even though my meter reads 0.010 days
As you can tell ,,, newbie
Thanks
 

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Hi
I have a question 12 volt 4s 100 AMP top balancing
Are my cells balanced ? , even though my meter reads 0.010 days
As you can tell ,,, newbie
Thanks
measure the voltage of the individual cells at the cell terminals.
You want to see them all within millivolts of 3.65 volts.
If yes then terminate the charge as you cells are top balanced and full.
They will settle as low as ~3.45 volts over the next 24 hours.
That is expected.
 
Last edited:
Thank you very much
The "within" factor is what I thought but I wanted to make sure
My cells are at 3.64
 
Thank you very much
The "within" factor is what I thought but I wanted to make sure
My cells are at 3.64
2 significant digits is 10 millivolts precision.
I guessing that is the max precision of your meter.
I would call them balanced and terminate the charge.
Its extra wear and tear to keep the cells exposed to charge voltage after they stop accepting current.
 
Thanks
I was wondering about that.
Leaving them on a charger too long even when I have the charge set to 3.65
 
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