Valence U1-12RT Lithium Battery

Anybody have any direct experience with these?



I was recently given two Valence U-Charge U1-12RT 40AH battery modules that were salvaged out of some hospital med carts. I’m not sure how old they are because I can’t make sense of the serial number tag.

These are (were?) marketed as “drop in replacement” for lead acid batteries, and each one has its own built-in BMS, and a pair of communication cables so they can talk to each other over an RS-485 interface.

The charging specs suggest that I could use my camper battery charger or my Redarc DC-DC charger on them, as both top out at 14.6. I’m not really concerned about the float voltage because I’d probably not have them connected to a charger all the time. I’ve only had time to play with them a short while, but they charged up till my Vector charger said they were “Full”, then held 13.3 for several days.

I have them paralleled right now, and I’m running them down with a small MSW inverter and a 150 watt heater. The user guide talks more about connecting them in series than parallel, and I’m not sure the communication cables even need to be connected when they are paralleled. According to the documentation, there is a Battery Discharge Indicator (BDI) and a diagnostic kit for these batteries, but I haven’t had time to find out if they are still available. My understanding of the User Guide however is that the BDI is required for a series connection.

I’m not sure what to do with these yet, and I don’t think I’d want to replace my group 31 AGM battery in the camper with these just yet. What about connecting them as a secondary battery bank on a four position battery switch ( Batt 1/Batt 2/ 1+2 / Off ). Due to their small size, I could make a place to stash them inside the camper without too much trouble. They could possibly be a good source of overnight power (especially in the winter) that I wouldn’t have to worry about running them down below 50%.

U1-12RT Data Sheet

Valence RT User Manual


:):)