Orion-Tr 24/12-5 for trickle charging lead-acid starter battery?

DIY
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1

I have a system with a 12V AGM starter battery and alternator (max about 14.4V), and a 3kWh 24V house battery (LFP). I’d like to leave an Orion-Tr 24/12-5 connected at all times from the house battery to the starter to keep the starter battery from going flat. The 24/12-5 is listed as having a 12.7V output, which sounds fine.

Any issues with this? Can I leave the Orion connected to the starter system even when the alternator is running, or do I need to disconnect it? I could put a big Schottky on its output to protect it, or use the ignition to disconnect a relay.

I have a larger 24/12-70 in the system, but using that would require a current limiter.

Thanks!

2

That Orion is not designed as a charger, only the Orion TR Smart and the Orion XS are officially designed for charging.

3

Officially, yes. But lead-acid can usually take even an unregulated voltage (eg direct connection from a solar panel) as long as the current is low enough.

It’s more a question of whether or not the Orion can withstand the higher voltage from the alternator being applied, plus possible voltage spikes.