BMS help

[slowbutsure]

Hi, my BMS says the soc is 65% with average cell value being 3.27 (all very close). However, it’s not taking in any charge from the charge controller. The settings all seem fine so I just don’t get it. Could the BMS be faulty or am I missing something?

 

[slowbutsure]

This explains what you are seeing.
https://aklectures.com/lecture/term...orce-terminal-voltage-and-internal-resistance

Try it again and take a reading of the battery voltage under load. Once you have turned off the appliance, wait a while and watch as the voltage of the battery increases. My lithium packs do after running the aircon and with my AGM battery it will show well below 12V and then climb steadily once I have turned off the power.

Thanks.

 

[slowbutsure]

I’m still having my original BMS issue, which I’m wondering if my Daly BMS is faulty. The cell volts are at 3.34 and the bms is not allowing any more charge into the cells. I don’t get it. Absorption is set at 3.45 and float at 3.4. I’ve attached screenshots of the bms app. Can anyone see why it’s shut off charging? Thanks!

 

[Ellcon123]

Charge and discharge fets are on so I don't see the BMS stopping anything. Is there anything coming out of the charge controller?

 

[slowbutsure]

Charge and discharge fets are on so I don't see the BMS stopping anything. Is there anything coming out of the charge controller?

Yes there is current coming out of the charger and it’s in bulk mode. As you can see from the screenshot the current is zero on the bms. I really don’t get it.

 

[Ellcon123]

BMS can only control in on/off fashion. It's on so must be the charge controller. If power is coming out, where is it going? I would set all the charge controller settings to 28V and see if that starts charging.

 

[Ellcon123]

Just read your post #83 where you state power is coming out of battery but no charge in. How much solar do you have? If loads are greater than supply then the battery will draw down.

 

[slowbutsure]

Ah sorry, this is a schoolboy error. A breaker had tripped. The breaker was hidden behind the battery, I forgot it was there.

 

[Tim Tim]

Ah sorry, this is a schoolboy error. A breaker had tripped. The breaker was hidden behind the battery, I forgot it was there.

And you aren't the only one in this world that has missed such a simple thing. Welcome to the DUH! Club ?.

Ok glad you got it sorted.