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tonyjobson avatar image
tonyjobson asked

Smart Battery un-balancing zero load

Hi Everyone,


I recently got a 100Ah smart battery. On initial receiving the battery before i took it out of the box cell #2 and #3 were 0.3 Volt lower than the Cells #1 and #4.

This was a bigger difference than i expected on a brand new premium battery but I figured it was within tolerance.

I've ran the battery on a very slow charge and got all cells balanced to within 0.01 V.

I've used the battery a for one small discharge test of maybe 15 or 20% taken out of the batteries.

let the charger recharge back up to 100% and it was balanced within 0.1V across all cells after the charger went into float.


I've now left the battery and charger in float for 2 days and I'm back to a cell voltage difference of 0.05 V in just 2 days with no load on the battery at all.


0.05 V in-balance in 2 days with no load looks very poor.

This worries me. it looks like i might have a couple of bad cells.

Any thoughts?



Lithium Battery
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3 Answers
mvader (Victron Energy) avatar image
mvader (Victron Energy) answered ·

Hi @TonyJobson, I am quite assured that there are no bad cells. We've very recently found a firmware issue causing cell 2 & 3 to be discharged faster then cell 1 & 4 - in standby. Not causing any harm to the cells or their life time perse, but causing an imbalance which reduces usable state of charge.

Currently, we are still in the middle of releasing the improvement.

To solve it now: download the new firmware (v1.19) from https://professsional.victronenergy.com, -> firmware section. And install it using the method explained in the change log you'll find there.

Or, wait until next week - then we'll release a new VictronConnect version that will automatically update the firmware for you once you connect: no need to download or select anything yourself.

Once installed and balanced (which is done by fully charging them); all will be OK I'm sure.

My apologies for this issue!


ps - could you post the serial number here? (HQxxyy.... ) ? thank you.

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tonyjobson answered ·

Hi Mvader,

It is hugely reassuring to know that this problem is undersold and a fix in coming.

I'm in no major rush, just knowing that this is not bad cells and that the fix is on the way is great.


Thank you for your fast response.


My serial number is hq2009cpvlv

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tonyjobson answered ·

Got the update on Monday night from play on Android and applied the firmware upgrade.

very smooth process took less than 2 minutes for the battery. on reconnecting to the battery i could see each balance circuit also got a firmware upgrade - another 4 x 20 seconds IIRC.

turned my multiplus off and on to initiate a bulk & absorption and float cycle and left it.


checked this morning and all cells locked at the same voltage of 3.37


looks like this worked perfect. thanks!

T.

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