BMS battery voltage not equaling cells

GEM Forum
1

Got another fun one here:
So I have one of the cheap Chinese BMS systems in my car with a Bolt 24 cell battery.
Per the attached pick, you can see the BMS thinks the charge is 98.8v, but if you look at the cells they average 4.074 or a total of 97.7?
24x4.1 = 98.4 so the cells seem to be closer to what I would expect but I don’t know where the 98.8 is coming from? There must be a calibration that I am missing.

PS - When I pulled the plug on the charger at 99v it was still only one light off full current so the charger appears to think the 97.7 is correct as well at it had bearly started to ramp down the charge to 98.5 (#177)

@Inwo

Image
Image.jpeg3024×4032 1.95 MB

2

Picture doesn’t show what app you are using. I think you need one that matches the hw better.

3

I am using HYR BMS and VBMS - both show the same exact info.

4

I use hyr here.
I think “bms” is another.
When working correctly the voltage numbers make more sense.

It was “vbms” I was thinking of. I have the original Chinese app, but that one reads goofy like yours. Let me see if I can find it.

5

“HYR BMS” is the name of the whole app, so I have that one and VBMS

6

I sent you what I think is the original 3.2apk

7

How did you send it to me? I can’t find it in my email or in a PM on the forum?

Thanks
Mike

8

image

9

I have the HYR BMS app with the cheap Chinese bms and it shows about 1 volt higher than the actual voltage. Doesn’t bother me as I know it’s off so I just adjust for it. I don’t think the AH reading is accurate either on mine.

10

Hello,
does anyone have a newer HYR BMS than 1.0.0?
Please send me the apk.
Thanks, Harry

11

Have this.

image
image366×516 34.2 KB

12

Pls can you send me the apk-file?

13

https://1drv.ms/u/s!AnakAGFbkD4yiTtd4a5NoEzOtL8M

14

Thank you very much, I’ll install it for my Fiat Panda right away :slight_smile: