Will Optimate Smart Battery Charger Also Prevent Backfeeding to Tow Vehicle Battery
Updated 01/08/2026 | Published 01/07/2026
Question:
I am installing a lithium iron battery on my travel trailer. My Toyota 4runner has line power to the 7 wire pin. Do I need to install a dc2dc charger with the addition of the lithium battery to the travel trailer. My goal at this time is not to charge the trailer battery with the car but charge it with a generator or shore power. I had heard inch you-tubeinch that without the dc2dc charger and charging lithium iron battery via your 7 wire connection can damage your tow vehicle alternator. My primary concern is to prevent damage to the Toyota 4runners alternator system. Can the MA99JR provide both alternator protection plus supplimental charging to the travel trailer lithium iron battery at the higher voltage 14,6 VDCrequiremens of the lithium battery. Please advise.
asked by: Tom M
Expert Reply:
Hey Tom, yes the Optimate Smart Battery Charger part # MA99JR will do both things you've mentioned. It will put a maintenance charge on your trailer battery and will also protect your tow vehicle's charging system as well as it won't let the trailer battery backfeed onto it. What made you decide to switch to lithium.
Product Page this Question was Asked From
OptiMate Smart Battery Charger - DC to DC - 12V - 2 Amp
- Battery Charger
- Battery Charger
- Car/Truck/SUV
- 12V
- Charges and Maintains
- AGM
- Gel
- Lead Acid
- Lithium
- Vehicle Battery to Auxiliary Battery
- Smart Charge
- Trickle Charge
- OptiMate
more information >
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Tom M.
1/8/2026
I went to Lithium to provide adequate powered to run a couple of cpap machines and provide power while boondocks for a few days while travelling.