- Jul 16, 2024
- 6
- 7
- Funster No
- 104,649
- MH
- just looking
Following recent purchase of 3yo Rollerteam 746.
Prior owner had already replaced the existing leisure battery - with dual 110ah lifepo4 batteries. “ LIFOs Go”. I have not yet had a chance to review wiring in detail. However, the original leisure battery was located under front bench of the rear facing travelling seats - next to Truma combi. As such, I assume the main + and -ve hab connections/shunt are also here. I also assume these connections have been extended - to the replacement lifepo4 batteries, which are now to the rear of the vehicle.
For reference, there are 2 PV panels on the roof and a pvlogic mppt. These are definitely providing charge to the batteries - I’m able to verify via the pvlogic and battery bms apps.
When on mains hookup, the bms shows 70w of charge (per battery) at about 6amps - from the original nordelektronica ne297 charger. Based on basic research, this charger doesn’t have a lithium profile hence I am not entirely sure whether this charger is harming the batteries. That’s the first question.
My second qn relates alternator charging. I am pretty sure there isn’t any. Like inspecting the wiring, I’ve not had a chance to look at connections. All I know is that when the engine is running, the bms reports state as discharging w/ 10-20w of draw from the battery. This is with all hab devices/control panel off. I therefore cannot explain where this draw comes from? Perhaps the new lithiums are also connected to the cab battery and the cab devices (fan, lights) etc are using power. Then again, this doesn’t make sense as surely the alternator would be supply charge to the cab battery, and in turn the lithiums - which would would surely severely drain the cab battery and/or damage the alternator given that (as I understand it) lithiums can draw (almost limitless) current vs “traditional” batteries? Obviously I plan to review/trace the wiring, however how else would you recommend I diagnose what is happening?
Once I understand what is going on, I will add a victron b2b and replace the nordeletrika mains charger with a “better” lithium-compatible victron equivalent. I will also replace the mppt - in readiness for more solar - which will follow as part of a “step 2.”
Thanks a lot!!
Prior owner had already replaced the existing leisure battery - with dual 110ah lifepo4 batteries. “ LIFOs Go”. I have not yet had a chance to review wiring in detail. However, the original leisure battery was located under front bench of the rear facing travelling seats - next to Truma combi. As such, I assume the main + and -ve hab connections/shunt are also here. I also assume these connections have been extended - to the replacement lifepo4 batteries, which are now to the rear of the vehicle.
For reference, there are 2 PV panels on the roof and a pvlogic mppt. These are definitely providing charge to the batteries - I’m able to verify via the pvlogic and battery bms apps.
When on mains hookup, the bms shows 70w of charge (per battery) at about 6amps - from the original nordelektronica ne297 charger. Based on basic research, this charger doesn’t have a lithium profile hence I am not entirely sure whether this charger is harming the batteries. That’s the first question.
My second qn relates alternator charging. I am pretty sure there isn’t any. Like inspecting the wiring, I’ve not had a chance to look at connections. All I know is that when the engine is running, the bms reports state as discharging w/ 10-20w of draw from the battery. This is with all hab devices/control panel off. I therefore cannot explain where this draw comes from? Perhaps the new lithiums are also connected to the cab battery and the cab devices (fan, lights) etc are using power. Then again, this doesn’t make sense as surely the alternator would be supply charge to the cab battery, and in turn the lithiums - which would would surely severely drain the cab battery and/or damage the alternator given that (as I understand it) lithiums can draw (almost limitless) current vs “traditional” batteries? Obviously I plan to review/trace the wiring, however how else would you recommend I diagnose what is happening?
Once I understand what is going on, I will add a victron b2b and replace the nordeletrika mains charger with a “better” lithium-compatible victron equivalent. I will also replace the mppt - in readiness for more solar - which will follow as part of a “step 2.”
Thanks a lot!!