Happy 15th Birthday to my LiFePo4 Bank

[AMCarter3]

Really nice to see you back and in good health, Rod!

[CaptainRivet]

Originally Posted by jcapo

There are two Epoch 300AH versions. My 300AH Epoch "Essentials" batteries were configured to start balancing at 13.6 with a 10mv deviation.

I changed the deviation to 5mv and then to 2mv to watch the balancer work.

better but correct would be a mixture of both, 10mV at 13,4V or 3,4V.
3,6V is by far too high and too less time for a passive balancer to sort an imbalance before it gets a problem.
Common agreed practise is 3,55V or 14,4V absorption (duration adapted to your installation) at float 13.5V to not keep it on a too high voltage.
Then reduce absorption step by step to a voltage between 14,4V and max 13,8V, depending on quality of your cells and c-rate used when th battery still stays in balance with your (passive balancer.
If your battery contains parallel cells highly recommend not to go below 3,55V in absorption because parallel cells can only even each other completely out in the knee above 3,4V. Below small differences due to flat curve and production deviation between parallel cells are kept and causing a future imbalance of the battery, only in the upper knee it’s possible they can equalize each other to > 99.5%.
So 3,6V is never reached other then when top balancing the battery.

[Maine Sail]

Originally Posted by CaptainRivet

Wow that’s bad, means >100mV deviation at 3,65V when they start balance and then a tiny passive balancer should sort that quite big imbalance. On a 300AH battery 100mV at 3,65V is about 1AH difference means it takes weeks till that’s in balance.
Heard a lot good about epoch but that’s a noGo…they should have taken Jk BMS instead jbd one…2A active balancer balanced down to 5mV deviation.

I have never seen an Epoch with a 100mV v-Diff. Epoch does not use JBD BMS’s.. While I currently use a JK if I was using this bank on a boat again I would re-install the REC.

[CaptainRivet]

Originally Posted by Maine Sail

I have never seen an Epoch with a 100mV v-Diff

Well if your starting balancing at 13.4V only at 30mV with a passive balancer then you end up at >100mV at 3.65 doesn't matter which manufacturer. Thats more then 1AH deviation/imbalance at 300AH battery.
Most likely the 30mV were false and 5 or 10mV at 13.4V was correct.

A rec will never make it into a drop in, too expensive and also complex to connect relays to battery....
Jk is the best of the mosfet BMS crowd so best to go with it for a dropin. But you see a lot off daly and jbd in drop ins
The op said he using JBD app on epoch so it must be jbd or a derivate of it maybe with epoch custom features. i told him to use the Epoch app.