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Hi there,
I was wondering if anyone has experienced or can explain why when I connect two 100 amp LifeP04 batteries in parallel and start charging them with the 24v smart charger is always in bulk charging mode even if the battery lcd shows they have been recharged.
The other aspect I'm unsure about is it normal that the app shows the voltage being around 28 plus but 0 under the voice of CURRENT.
Any help would be appreciated.
Cheers
Assuming these are 24V batteries.
Sounds as if the internal BMS in each battery has cut the charge due to being full or over voltage before the charger recognises it.
In fact, the batteries do appear to be discharging differently.
Also, the faster-discharging battery is getting up to a 15.2 V which it shouldn't and probably that's another sign of faulty BMS I think...
Looks like it from your comment, but the question said parallel.
If they're 12V batteries, charge both separately to the same voltage, but preferably full. Once one decides it's fully charged, it cuts the charge to both.
Probably a good idea to look at installing a battery balancer.
I have two 12 V in series to get 24V for a trolling motor.
From new they appeared to be discharging at a different rate with only one discharging the other not according to the battery LCD.
Also, they get to different voltages when fully charged one at 13.3V and the other at 14.4V
I'm in the process of testing it individually to see if I have to return it under warranty.
Would it be ok t have a battery balancer battery on series?
If it is any suggestion?
Thanks heaps for your answers
Battery balancers are for keeping series batteries balanced.
From your description the batteries are badly out of balance and have been from new. If you can get a low power 12V charger on the low battery and leave it until the voltage comes up to 14.2V you may be ok. Will take a while.
Take a look at fitting a balancer. Once the voltage across the batteries reaches about 27V, it applies a small load to the higher battery until the voltages equalise. You can download the manual and datasheet for more information.
https://www.victronenergy.com/batteries/battery-balancer
