Lithium installation problems

[ABQRV]

Help! I just installed 2 Dakota 100ah lithium batteries in my Dynamax REV 24 CB replacing the lead acid. Batteries in parallel. All the existing wiring was reattached in the same orientation. Something is not working. There seems to be an overload switch that is tripping and than will reset later. For instance, cabin lights can be turned on but when heater fan is added to that, everything shuts down. Hoping this is an easy fix to isolate.

[SmackIt]

Did you try using just 1 of the Dakota batteries and then swapping?

[TitanMike]

A question that has to be asked, "Are the batteries fully charged".

If low, the internal BMS will shut the batteries off when low voltage limit is reached (a protect mode). Lights don't draw very much current but a heater/furnace can draw many times more that current. On my TT all the lights draw only a little over 1 amp. The furnace draws 3-4 times that and larger furnaces can draw even twice or more than mine.

The extra current may draw down battery voltage enough to shut it down.

Do you have a true battery monitor or just the LED push button type.

If the latter, a nearly dead LiFePo4 battery will show that it's still charged on the LED type type used as OE in most RV's.

[ABQRV]

Thanks. They sure seem to be fully charged. On the charger all night and showing full by voltage meter

[TitanMike]

If all was working fine before the change then focus on only what you changed.

Batteries

Wires connected to the batteries

And lastly any fuses/circuit breakers inline with the batteries.

[NavyLCDR]

Originally Posted by ABQRV

Thanks. They sure seem to be fully charged. On the charger all night and showing full by voltage meter

Is it a charger made specifically for lithium batteries?

[ABQRV]

Update. So the batteries seem to work great. I think the “bridge” switch and it’s related solenoid on the dash may not be working right. If I stay away from that and just use the new lithium batteries, everything is fine. The free charger I received with the batteries was a 24V not a 12V but I don’t think that had an impact on the one time I used it to charge. I’m getting Dakota to swap that out and will hardwire a 12V in for charging from shore power. It’s only 10A so would imply a 20 hour charge on my 200 Ah battery bank. May get a higher amp charger later. Also ordered a special DC-DC charger which is needed to protect the alternator when driving. It includes a Bluetooth monitoring app for optimizing the the connection between alternator and batteries. Thanks for the suggestions from the group! Happy Thanksgiving.