Ram 1500 5700 E battery Voltage

[Brian2021Ram1500Ltd]

Just replaced 12v battery on 2021 RAM 1500 Limited 5.7 eTorque. With original battery when running voltage would be 13.7 to 14.1 v. With new battery voltage ranges from 12.6 to 13.7 with no logical explanation, high speed, low speed, at initial start, after 90 minutes at highway speed.... Examples: at highway speed voltage show 13.7 for 70 miles and then at off-ramp dropped to 12.6-12.7 and stayed at that level for last 10 miles of trip. Last evening 13.7-13.8v for 80 mile trip; shutdown for 3 hours, then upon restarting 12.7v and stayed at this level for entire 80 mile return trip at 70 mph. Does not seem normal so taking to dealer to check system.

I'm having a similar experience...2021 model with eTorque. 12v battery was completely dead one day. Boosted and system indicated many issues, which Ram dealer told me were low voltage warnings. They say they tested and all passed, but said maybe the 4 year old 12v battery was culprit. I replaced the battery and it was a little better...running voltage reads 13.8-13.9 initially (instead of 13.2-13.8 with original battery) and then drops to as low as 13.4-13.6 and pretty much stays there after driving for a while. Other interesting thing is that when stopped at a light and system stops the engine: Initially, when running voltage is 13.8-13.9, the voltage doesn't drop when engine cuts out (i.e. 48v->12v charging system is working?). When the runnning voltage is 13.4-13.6, the stopped voltage drops to 12.4-12.8 (I think this means the 48v->12v charging system has stopped working). Before all of this started, I'm almost certain the battery voltage was always 14.0-14.1v (running or stopped).

I haven't seen any solution to this issue on the forum yet. Has anybody solved it yet?

I'm beginning to suspect that the 48v battery may be the culprit if it is having trouble maintaining a charge since it feeds the 12v charger and might explain the declining voltage after running for a while. Does anybody know if there is a method for testing out the 48v battery?

 

[Jmac509]

The E Torque system runs at 13.4-13.6 on the gauge normally. Only the Non E torque trucks run 14+.

 

[Brian2021Ram1500Ltd]

The E Torque system runs at 13.4-13.6 on the gauge normally. Only the Non E torque trucks run 14+.

Just curious how you know this...I couldn't find any official documentation on what "normal" is for eTorque systems. Seemed mostly like a wide range of opinions. As I mentioned, the charging/voltage behaviour in my truck changed in the past year or so. If you're right, then perhaps one of the firmware updates in the past year has changed the charging algorithm so that it acts like a float charger when the battery is fully charged and disables charging on auto-stop on full charge.