Ecotrek discharge relay failure?

[Ken Allan]

Looking for help. KS2 Ecotrek battery in 2018 Hymer Sunlight2. Two rev "H" batteries. Rear one works properly. Front battery is full charge but by itself will not stay online when reset button is pressed. If reset button is held down, power engages but let go and power shuts off. It appears that the discharge relay inside battery has failed. Occasionally, the reset will hold on for a minute but then disconnects. If relay was external I could test it.

There were some extensive posts on Ecotreks but I haven't seen anything on this particular problem.

Can relays be repaired? This is a new problem for me so I'm just starting to explore. I will try to contact KS2 but expect they will tell me to buy a new battery $$$. Suggestions? Thanks.

[JohnP]

I've seen this issue come up on the Hymer Aktiv Facebook group. If you don't get any help here you may want to join that group and post your question there.

[Cof3933]

I had the same problem, but I don’t have a fix for you. KS2 said I would have to buy a new one and it would be $3500. I was not willing to buy a replacement for that price from the people who built it and it only lasted 1.5 year. I replaced the Ecotreks, inverter/charger, solar controller, the AGM battery, rewired 75% of the electrical, and corrected the wiring.

[Ken Allan]

I had several conversations with KS2. As is common with these Hymer MoHo's it was wired with charging being done on the dis-charge side of the batteries. I corrected the wiring per KS2 schematic. This did not have any effect on the Front battery dis-charge relay kicking out. I did a series of tests that still lead me to believe that the front battery cells are OK but either the dis-charge relay (or BMS) is at fault. With the battery ON it will charge normally and charge will turn off. And also if I depleted the voltage to 12,6 volts battery will go offline. You may grit your teeth but I found no problems after locking down the reset button for several days.

I did join, search and ask the facebook groups. I found no real answers. Most responses had a version of... cells are unbalanced (with no explanation of how to correct) or go buy new batteries. Not very helpful.

KS2 offers no repair service, just new battery... Per KS2 11/2/21: The cost of replacing the battery to our latest revision the L3 is the following: LFP L3 2400 12V Battery__KS-2400-12V-L3__$2,799 each__+ shipping(150-300). To accommodate customers affected by the situation with Hymer, for a limited time we offer an L3R(refurbished) for $1,805.00. It's practically a brand new battery with brand new cells and it comes with a 2 year warranty. $ Canadian

----In conclusion... I am planning to just make a latch to hold down the reset switch so I can utilize this FRONT battery if needed. I'll use these "H" batteries until they wear out or fail... and convert to another brand!