2018 RT UHG will not charge Ecotrek lithium

[andyjaneen]

I have a (new to me) 2018 RoadTrek CS Adventurous with 2x KS2 Ecotrek RevH, 200Ah lithium batteries. I am not able charge the house batteries from UHG (or sometimes called GU) or driving.

Shore power works great and will fully charge up to 13.8-13.9v. Solar seems to at least maintain, but UHG does not charge batteries. Funny thing is, if I manually hold the momentary Reset button down for each battery bank they charge very quickly via UHG.

My guess is BMS is somehow shutting it down. Any ideas how I can troubleshoot?

[Ken Allan]

If you haven't already tried this... You might be better asking this question on the Roadtrek facebook group.
https://www.facebook.com/groups/1676694222568818

These ecotrek systems are difficult to diagnos because you can't isolate components. Holding down the reset (I think) will close the contacts on the internal charge relay. Why the batteries will charge from the other sources but not the UHG sounds like an unusual problem. To my knowledge the BMS does not know or care where the charge current comes from. Maybe the UHG is putting out too high of a voltage ?? The Balmar regulator settings might need to be checked.

[mumkin]

Or even better the groups specifically for your model. the Zion/Simplicity Group.

https://www.facebook.com/groups/1735416186750462

[PattiT]

2018 Roadtrek Ecotrek ss agile how do you turn off the alarm on the lithium battery or reset the lithium batteries

[mumkin]

Originally Posted by PattiT

2018 Roadtrek Ecotrek ss agile how do you turn off the alarm on the lithium battery or reset the lithium batteries

I suggest that you join the Facebook group mentioned by Ken above.

[renegade]

About 2022 Thanksgiving on our last return trip of the season, we experienced the same battery charging scenario (suddenly no UHG charging, but shore power and possibly some solar OK). Dealership diagnosed as "burnt up" UHG and ordered a replacement from Nations. Fast forward to this Memorial Day 2023 weekend, we made a side-trip visit to Nations Starter/Alternator to drop off original UHG for refurbishment. They had it refurbished that same day and we could take it with us! Lesson learned --- Because we had the whole winter to get get it done, we should have had the original UHG sent in for inspection/refurbishment, sparing us the cost of an additional UHG purchased through the dealership (x2 Nations advertised price). Also, Nations replaced our shredded UHG belt and worn-out tensioner (original - @40K OD) which failed enroute. 2018 Roadtrek CSxl - one owner.

[Alan19067]

I have been through many electrical (and other) issues with my 2016 CS Adventurous Ecotrek. If you can find a good shop that is my recommendation. Even RT dealers I have worked with are reluctant to look at electrical issues. Beyond checking the wiring from the UHG and fuse for obvious issues take a look at the Balmar as someone else suggested. The Balmar (box on the firewall left side) has a display and that may help someone diagnose the problem. The Balmar can be reprogrammed if it is OK. If it is a power module (lithium battery) you are probably out of luck. The folks at K2S are very helpful, but unless someone is willing to open up the module there is not much you can do but get a replacement. We have a great shop in PA, a long way from you though.