Hi All,

I replaced a faulty board on Pylontech US3000c but the SOC is now incorrect causing overcharging of the battery and warning led's on bms board. I put back the old board and batteryview showed SOC = 96% but the new board shows SOC= 70%. Any ideas what the procedure is / how to reset this. The cycles has also reset to 0. Is there a way of changing this?

Any help appreciated.

Thanks

2 hours ago, GreenMonster said:

Hi All,

I replaced a faulty board on Pylontech US3000c but the SOC is now incorrect causing overcharging of the battery and warning led's on bms board. I put back the old board and batteryview showed SOC = 96% but the new board shows SOC= 70%. Any ideas what the procedure is / how to reset this. The cycles has also reset to 0. Is there a way of changing this?

Any help appreciated.

Thanks

It shouldn't cause the batterybto be overcharged as the current will tail to zero as long as the max voltage is correct.

Hi, the cell imbalance starts going crazy (Pic1) and the cell warning LED's light up (pic2).

The SOC in PIc1 shows 86% vs 100% for other batteries.

I also compared cell voltages while batteries charge and the SOC is definitely incorrect

I haven't tried to contact Pylontech directly. Are they helpful with this type of query?

14 hours ago, GreenMonster said:

Is there a way of changing this?

Can be set via CLI. It is super-complicated, great for getting extended info, but never worked for me when I tried to set the SOC. 

But the incorrect SOC is not your problem. SOC will auto-reset once all the cells ale balanced and charged to the top.

Edited January 30Jan 30 by Youda
better wording

2 hours ago, GreenMonster said:

I haven't tried to contact Pylontech directly. Are they helpful with this type of query?

They are. But there is a New Lunar Year celebration going on in the Asia right now. Nobody will work for weeks. Upon returning to the job, they will clear their mailboxes so do not expect any answer if it will not arrive on the second day.

@GreenMonster the problem is not the incorrect SOC, but the cell imbalance.

Some of the cells have more charge than the others, which causes that their voltage goes up too quickly at the end of charging process.

You need to either discharge these cells a bit, manually using an incadescent bulb for example, or wait for internal balancer to do it for you.

The green SMD LED is not a cell warning light, it's an indication that internal balancer is working on that particular cell.

Just lower the charging current to 1A (bench LAB power supply would be great for this), or even stop it completely. Then wait a couple of hours for the balancer to do it's job.

Meanwhile, check the readings and lights.

Once the imbalance is solved, continue with the slow charging.

The SOC will reset to 100% automatically, once all the cells will reach cca 3,46V.

Thanks for the feedback. Will try what you suggest.