question

Sinbad avatar image

BYD SOC acting strangely

Hi all

So lately I've noticed while my batteries are recharging in the morning that SOC jumps from 82% to 99% pretty much instantly.

BYD B-Box 10.25 v4.22 firmware

SmartSolar Charger MPPT 250/60 v1.39
MultiPlus 48/5000/70-100 v433
CCGX v2.33



This has happened the last 3 days in a row...

Any ideas why this may be the case?


Thanks!


BYDcharging
1570447135067.png (18.8 KiB)
1570447258403.png (62.2 KiB)
1570449504492.png (42.8 KiB)
10 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

3 Answers
laurentiu.pitran@gmail.com avatar image

hello,


time to time i have same way of acting on battery charging - same BYD.


example.png (217.2 KiB)
3 comments Share
10 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Thanks! Do you also see a slow discharge at night while there's no load on the battery? (Looks like it from your picture)

hi,

i have usual night use from battery due the surveillance system as the heat recovery system.

you can see this in attachment, on negative part of graph ,where negative is taking power from battery.

anyway, there is big difference between energy used and reported by BMW and energy used and reported by BYD bms; more of this i have an separate hardware to measure energy amount that is used or filled into battery.

night-use.png (309.8 KiB)

to argue, i will attache more

night-2.png (254.8 KiB)
night-3.png (269.1 KiB)
wolfgang avatar image

I had the same problem. The charging power in amps from 90 to 100%. was too high. 40A is too much. I now switch on a load and reduce to max 10A then it goes on. From 95% SOC only 5A at 100% only 1A then finish switch off. I have watched my Tesla Model S loading from 90 % is slowly reduced to 1 A at 100% SOC

Share
10 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Guy Stewart (Victron Community Manager) avatar image

Once the target voltage of 56.5V is reached, the battery is considered full, and will reset the SOC.

So that part is normal and expected.

Any other changes in the system to lead to the variance in behaviour?

There have been some adjustments made in default behaviour when managed batteries (like BYD) are detected in Victron systems, though I didn’t know that this had already been rolled out in those firmware’s.

3 comments Share
10 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Thanks for the response, Guy.

No, no changes in the system (except my load has gone down, so the system is more likely to reach 100%.)

Wondering if this is also related to the slow drain I see overnight while the load is powered from grid - you can see the SOC going below the min set point in the graphs above - min SOC last night was 60%, previous night was 65%

If the load has gone down is there a chance that the SOC jump corresponds to the energy discharged slowly?

Hi

Not sure I understand your question here.


But it seems the jump in SoC corresponds roughly to the overnight discharge that I see (when there is no load on the battery at all)