ok so this is just the general overview and my numbers are off so you will need to check your manuals for the batteries and your setup. The way the charges detect how full the batteries are is by checking the voltage on the line, since they are parallel one battery will put out 14v so the charger sees it at 14v so it then stops charging and goes into maintenance, the charger doesn't detect each battery separately. I think you need to charge the batteries separately until they are the same voltage (tolerance is 0.02v I think, check the manual for your batteries). then add them back in as normal. The concern I have here is why is one so used when the other one isn't, dropped cell? Disconnect the batteries and test the voltage on each battery and see what the voltage is. also check if the manual for the battery has a recommendation on how to prepare them to go into parallel, ie charging state etc. for the battery that's low, if its charged separately does it reach 100%, and what is the voltage at on both batteries after a rest. Note: I'm no expert, I'm far from an expert so hopefully someone who has more knowledge then me can chip in.
Just subscibed. We are in the same yard doing up our catamaran. We are in the same spot that you were prior to your launch. Enjoying your videos. I think the problem you are having is that although the batteries are tedhnically in parallel they are not in a balanced configuration . Will pop round and see you tomorrow if you are around. Best regards john and dawn
If the batteries were connected in parallel then the terminal voltage of both would be the same. SO somewhere your batteries are not wired as you think. Which at 12v can just be a dirty connection. Disconnect the high battery and see what the system does to the low battery for a first guess. Very carefully check that all links are what you think you have designed. vert carefully check that all the cable connections are clean and tight. Do your batteries have an individual charge controller? Does it offer a smartphone app???? If so install it and see what both battery's BMS is saying, the BMS could give you all the answers.
ok so this is just the general overview and my numbers are off so you will need to check your manuals for the batteries and your setup.
The way the charges detect how full the batteries are is by checking the voltage on the line, since they are parallel one battery will put out 14v so the charger sees it at 14v so it then stops charging and goes into maintenance, the charger doesn't detect each battery separately.
I think you need to charge the batteries separately until they are the same voltage (tolerance is 0.02v I think, check the manual for your batteries). then add them back in as normal.
The concern I have here is why is one so used when the other one isn't, dropped cell?
Disconnect the batteries and test the voltage on each battery and see what the voltage is.
also check if the manual for the battery has a recommendation on how to prepare them to go into parallel, ie charging state etc.
for the battery that's low, if its charged separately does it reach 100%, and what is the voltage at on both batteries after a rest.
Note: I'm no expert, I'm far from an expert so hopefully someone who has more knowledge then me can chip in.
Just subscibed. We are in the same yard doing up our catamaran. We are in the same spot that you were prior to your launch. Enjoying your videos. I think the problem you are having is that although the batteries are tedhnically in parallel they are not in a balanced configuration . Will pop round and see you tomorrow if you are around. Best regards john and dawn
If the batteries were connected in parallel then the terminal voltage of both would be the same. SO somewhere your batteries are not wired as you think. Which at 12v can just be a dirty connection. Disconnect the high battery and see what the system does to the low battery for a first guess. Very carefully check that all links are what you think you have designed. vert carefully check that all the cable connections are clean and tight. Do your batteries have an individual charge controller? Does it offer a smartphone app???? If so install it and see what both battery's BMS is saying, the BMS could give you all the answers.