Is shore power bad for lithium batteries?

[NorAZogorbust]

Hello all, I am swapping out my two 6V lead acid batteries in my 5th wheel for a 300Ah lithium. My system is 12V with 400W solar and 100/30 MPPT charger. I will be connected to shore power for two months before I make the move to off grid and was wanting to find out if being on shore power that long will damage the new battery (I have been on shore power for over a month with my current 6V batteries). If so, what steps should I take to avoid damage? Thanks for any help!

 

[Ampster]

Lithium does not like or need to be kept at high voltage for a long time. There is no need to keep the Lithium batteries on the charger because they do not lose their charge as quickly as Lead acid batteries If you have other loads you want to run, just let shore power provide that power and disconnect the Lithium batteries.

 

[hwy17]

It would be best if you can disconnect the batteries entirely and let them rest while on shore power for long periods. Otherwise, just make sure the float voltage is acceptable for long term holding, 3.375/cell or less.

 

[NorAZogorbust]

Lithium does not like or need to be kept at high voltage for a long time. There is no need to keep the Lithium batteries on the charger because they do not lose their charge as quickly as Lead acid batteries If you have other loads you want to run, just let shore power provide that power and disconnect the Lithium batteries.

Thanks for the reply! I am told by RV experts that I need to have batteries hooked up for some RV electrical systems to operate properly. I am rethinking that maybe I should leave my current LA batteries installed and save my new Epoch lithium for my off grid journey which begins in two months. I have to stay on shore power in the meantime as I am in the Phoenix area and will need the A/C.

 

[NorAZogorbust]

It would be best if you can disconnect the batteries entirely and let them rest while on shore power for long periods. Otherwise, just make sure the float voltage is acceptable for long term holding, 3.375/cell or less.

Thanks Hwy17. It’s sounding like it may be best overall to delay the swap for a couple of months.

 

[Ampster]

I am told by RV experts that I need to have batteries hooked up for some RV electrical systems to operate properly.

That may be a generic answer that covers the reason that LA batteries need to be on Float. If you do not understand the specific RV electrical systems which need to be operated off shore power, what are you going to do when in the wild without shore power?

 

[NorAZogorbust]

That may be a generic answer that covers the reason that LA batteries need to be on Float. If you do not understand the specific RV electrical systems which need to be operated off shore power, what are you going to do when in the wild without shore power?

That may be a generic answer that covers the reason that LA batteries need to be on Float. If you do not understand the specific RV electrical systems which need to be operated off shore power, what are you going to do when in the wild without shore power?

You obviously misunderstood my follow up (guess I could have worded it better) but thanks for the kindness. I’ll seek help elsewhere.

 

[Rocketman]

When connected for long times…

I often turn the Multiplus inverter/charger to “inverter only” when solar is good and not needing air conditioning.

But on float it is set for 13.5v (3.375v/cell)

 

[NorAZogorbust]

Thanks much for that helpful information.

 

[Mark-]

Hello,

I traveled and lived in a diesel pusher for six years and some of the systems, like overhead lighting, were 12 VDC and connected batteries were required. The inverter/battery charger (Xantrex 3KW PSW) keep the batteries charged while on shore power. Other items like exhaust fans, smoke detectors, etc were also 12 VDC.

 

[Ampster]

Hello,

I traveled and lived in a diesel pusher for six years and some of the systems, like overhead lighting, were 12 VDC and connected batteries were required.............. Other items like exhaust fans, smoke detectors, etc were also 12 VDC.

Those are not systems that need to run when the RV is being stored and if that is the case @NorAZogorbust should be able to disconnect new Lithium batteries when the RV is being stored.

 

[Mark-]

Those are not systems that need to run when the RV is being stored and if that is the case @NorAZogorbust should be able to disconnect new Lithium batteries when the RV is being stored.

OP said nothing about storage.

 

[Ampster]

OP said nothing about storage.

I have obviously misinterpreted several things the OP said. I made an assumption that he had previously plugged his RV into shore power when he was not using it to keep the Lead Acid batteries charged. If his use case is different than I had assumed, and he has enough flexibility in his charging settings he could use a Float voltage the same or slightly above resting voltage for Lithium batteries and therefor could leave his RV plugged into shore power.. That setting would insure he would not damage the Lithium batteries by maintaining them at high voltage which a Lead Acid charging setting could do.

 

[Boomerweps]

When winterizing my RV trailer, I used my battery disconnect. That disconnected all but the SCC and I disconnected the panels from that. I do keep it plugged into shore power and the converter 12VDC operates everything but the emergency brakes and my inverter

 

[time2roll]

Thanks for the reply! I am told by RV experts that I need to have batteries hooked up for some RV electrical systems to operate properly. I am rethinking that maybe I should leave my current LA batteries installed and save my new Epoch lithium for my off grid journey which begins in two months. I have to stay on shore power in the meantime as I am in the Phoenix area and will need the A/C.

Yes some have components tied direct to the battery such as an electric jack on the front of a trailer or the emergency breakaway braking system. Generally if the battery is disconnected these wires are left dangling. Know what you have.

Also some have hydraulic slides and/or leveling that can pull 60/80 amps and relies significantly on the battery for this high load for a couple minutes.

Most RVs do not need a battery connected while parked.