New Member w/questions

[Pmd]

I’m a new member with a 2021 Roadtrek Chase purchased March 2022. I’ve had continual problems with my electrical system. The dealer has had the van more than I have. Are others having serious problems with their lithium batteries?

 

[Kevin D Pem]

What problems are you having?

 

[Pmd]

The batteries don’t seem to hold a charge for very long and often don’t charge completely when driving. The dealer had it for a month this fall, testing, communicating with KS2 & Roadtrek. It’s now in winter storage. I drove it once this winter and the batteries didn’t warm up to work. I’m thinking I should request replacement of the batteries.

 

[Kevin D Pem]

I would start with a battery monitor. The monitor will need a fully charged battery to begin with. You will need to enter battery size (amp hour). Without the monitor you will only be guessing about the battery condition.
Most of what you hear about lithium is bull, (it is not great). This is what you need to know! A lithium battery below freezing!: sometimes the battery will be destroyed in one charge, you can discharge, but not charge. the BMS Is designed to avoid this but!!!
A constant current power supply is needed to charge, the BMS regulates the battery charge. An Under voltage power supply means low charge state. As noted above, the BMS will disconnect below freezing if a charge current is applied, had you drawn current from the battery before starting the vehicle, the temperature of the battery would have been warm enough to have accepted a charge and not shut down. When warm enough it will reconnect.

To avoid thermal run away when the low voltage is reached, the BMS will disconnect as well. This feature will fool some charge controllers into shutting down. I have installed what I call a jump start switch to get things working again for a few of my friends. And this was needed with a controller designed for lithium.

The answer is enough amp hours to avoid this problem.

Ultimately you need to manage your power needs according to the system you have, this can be done with a battery monitor.

 

[Pmd]

Thanks for your detailed reply. I had hoped for an easy to use van with this Roadtrek I previously owned a Winnebago with lithium batteries and had no problem.

 

[Kayaktrek]

Thanks for your detailed reply. I had hoped for an easy to use van with this Roadtrek I previously owned a Winnebago with lithium batteries and had no problem.

We also have a 2021 Chase. Our battery issues began August 2022. There was a heavy rain and water was leaking into the coach. Also, even after charging the batteries with the UHG during the six hour drive, the low voltage alarm would go off after only 4 hours. The only appliance we were using was the refrigerator. Earlier that year we had been using the refrigerator for 24-48 hours on battery power with no issues. We took the van to a dealer who replaced the seal around the roof vent and did a battery reset, and updated the Firefly so we could do a battery reset if needed. We did not get the van back until late September. This seemed to resolve the issue although by that time we were at the end of the season (we live in New Hampshire) and could not fully test it.

In May 2023 we took the van for our first extended trip. The only appliance we were using was the refrigerator and even after extended drives with the lithium batteries engaged and charging with the UHG, once on site the batteries only show 13.1 or 13.0 volts after the UHG is disengaged and only go 8 or 9 hours before the low voltage alarm went off. The inverter is off so that’s not the issue. I tried a battery reset and that did not help.

The AGM house battery does not seem to hold a charge at all unless there is an external power source or the lithium batteries are engaged. On the Firefly, once external power is disconnected you can literally watch the house battery voltage drop and keep dropping until the lithiums are engaged. Yet, the dealer tested the AGM house battery and said it was fine.

When there is an external power source (shore power, solar or UHG) the batteries will show 13.7 volts but once the external source is gone, or the sun is down, even with a Firefly reboot the batteries drop to 13.0 and in 8 hours are down to 12.7 volts with only the refrigerator operating.

The solar controller display shows the batteries at 100% when there is solar or UHG power but quickly drops to 66% when only the lithium’s are engaged.

We reached out to Sean at Roadtrek who suggested a the load test of the AGM house battery. As mentioned above, this was done and was found to be normal. Sean has had little else to suggest except to take it to a dealer for testing and hopefully a diagnosis. Appreciate any insight anyone can offer as currently we only use the refrigerator and even that seems to draw down the battery system to a low voltage state in 6 to 8 hours unless there is an external power source in addition to the lithium batteries. Thanks.