SmartLithium Balancing issue

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jasontav asked Jul 3, '21

SmartLithium Balancing issue

Hi,

I have a pair of SmartLithium 12V/150Ah in series for a 24V battery. Both on v1.24 firmware.

One of the seems to be having a problem balancing. The other one is fine.

This is from the end of a 2hr absorption phase - you can see cell 3 is really lagging behind:

any ideas?

Lithium Battery BMS

redbattery.png (86.6 KiB)

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Answer 1 · 2021-07-03T10:51:49Z

Paul B answered · Jul 03, 2021 at 10:51 AM

Its not far out 0.04 volts is a small diferance and not enough to really worry about the bms will correct it over the next few weeks

or just keep it charging at 28.0 volts untill that cell comes up.

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Answer 2 · 2021-07-03T11:25:52Z

jasontav answered · Jul 03, 2021 at 11:25 AM

perhaps I should have mentioned, normally the batteries balance in about 30 minutes, so this is unusual/changed behaviour.

Also, that cell have been stuck at 3.48V/3.49V for about an 1.5hrs now. Normally I see voltage changes between cells fairly quickly,

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Answer 3 · 2021-07-03T12:34:53Z

Matthias Lange - DE answered · Jul 03, 2021 at 12:34 PM

The very first charging can take a few hours.

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jasontav commented · Jul 03, 2021 at 02:57 PM

this isn't a first charge - I've had the batteries approx 2 years

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Answer 4 · 2021-07-03T14:05:53Z

klim8skeptic answered · Jul 03, 2021 at 02:05 PM

Are you still balancing your batteries for 4-8 hours of absorption each month?

Battery Balancing..

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jasontav commented · Jul 03, 2021 at 02:59 PM

recently i have been doing 30 minutes a week and both batteries have balanced in that time.

because they hadn't this week I initiated a manual equalisation from the controllers (NOTE: I have equalisation set up for my weekly full charges/balances) and then saw the behaviour from the screenshot

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