Connect RV Solar, original 12 shore power and Lithium 12 Batt.

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New member
Sep 9, 2019
I have an old 5th wheel. I want to add solar and a 12v Lithium battery. Do I need to disconnect the old 12v inverter every time I connect to shore power (30 amp) to avoid damaging the brand new lithium battery? I have all the other accessories including the mppt charge controller.


Well-known member
Nov 17, 2018
Albuquerque, NM
You're not going to run or charge from shore power at all?

If the converter you have isn't capable of charging lithiums then you'd have to isolate the battery somehow.  If you remove or disconnect it, then all 12v devices are running from battery full time.  To check all the boxes you'd install a converter that can charge lithiums.

Mark B.
Albuquerque, NM

Gary RV_Wizard

Site Team
Feb 2, 2005
West Palm Beach, FL
First, I suspect you have a converter/charger rather than an inverter. That would have been standard equipment on an older 5W, whereas an inverter is almost surely an aftermarket install.  An inverter may or may not include a 12v converter and charger as part of its function.  An inverter makes 120vac power from battery 12v; a converter/charger produces 12v power from 120vc (shore power) to charge batteries and supply 12v power needs.
If it's an old 5W, the converter/charger may be old technology too, in which case it should berepplaced even if you stay with lead-acid battery(s). You will want a quality 3-stage converter/charger such as the Progressive Dynamics 9260 or a WFCO 9855.

Some 12v lithium batteries are designed as lead-acid battery replacements and charge ok on a charger designed for lead acid batteries. Other fare better if they have a charger designed specifically for them.

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