How to charge a starter battery from leisure battery?

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mathieu-dubuc asked Oct 18, '21

How to charge a starter battery from leisure battery?

Goal : I want to use my vehicle's indoor lights and ventilation during the night (3A 12V).

Setup : I currently have an independant solar and battery setup (700W solar 160AH of usable LiFePO4 battery)

Proposed solution : I think I could use an Orion-TR 12/12-9 converter taking power from my leisure battery and use the cigarette lighter circuit to charge the starter battery (15A fuse so everything seem alright). (The vehicule manufacturer said it's ok to let the car at "on" for long periods if I charge the battery.)

- Will it work?

- If I start the engine and the alternator is working at the same time as the converter, will it cause problem? (alternator and converter in parallel, seems ok from the manual from the possibility of paralleling multiple converters)

- Have I other solutions?

Regards,

battery charging Orion DC-DC Converters not smart alternator starter battery

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Answer 1 · 2021-10-21T20:03:25Z

kevgermany answered · Oct 21, 2021 at 08:03 PM

Orion will shut off when the starter battery voltage rises, so should be no issues, unless you have a smart alternator which may give much higher voltages than you expect. Best check max output from the car alternator and check it against the Orion specs.

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Answer 2 · 2021-10-21T20:23:04Z

scraggs answered · Oct 21, 2021 at 08:23 PM

Wouldn't a Cyrix work ok in this situation ?
Would want to be wired properly though.

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