Renogy DCC30S - what mains battery charger?

[meza]

Hi all, I've taken the plunge with lithium leisure battery and and Renogy DC-DC charger. (On a T5.1 so regular alternator)

I don't have a mains battery charger on board. I'd like to have something so when I'm on ehu both batteries will be charged.

I do have a spare very old 8amp car battery charger. Is there any way I can use this?

It charges around 12.5v.
Can I connect it to the alternator input of the renogy, will it do anything?

Alternatively I can get one of these 20amp Tracer lifepo4 chargers second hand. I guess connect that directly to the leisure battery, then when the leisure battery is full the renogy will divert current to the starter battery? Or will a lifepo4 charger shut off once the lithium battery is full?

I'm not on ehu often so don't want to spend a lot of money on a charger.

Thanks for your advice.

 

[TallPaul_S]

What do you have in your setup currently for EHU? What consumer unit? Any 240v sockets?

The normal set up to charge leisure battery on hookup would be a 240v charger wired into the consumer unit, fed from hookup. Then connected to the LB with appropriate fuses.

The DC-DC would be connected also to the LB but separately. There's zero issues having multiple chargers connected to a single battery.

With you're driving, the DC-DC would charge the LB, when not driving and on hookup, the other 250v charger would charge the LB.

If you also wanted to top up the SB when on hookup, the simplest way is with a 5a 240v charger plugged into one of your 240v sockets in the van, then plugged into a permanently live 12v cigarette lighter socket. Max 5 amps.

 

[Dellmassive]

Those old chargers are not suitable for charging lithium.

But you could as you say connect to the starter battery (alt input on the Renogy) and let it charge the starter.

At some point the Renogy will kick in and start charging the LB.

The Renogy will cycle on,/off as the starter battery rises and falls, but that's expected.

If it was me, I would just get a new smart charger.

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Apart from that, some people fit two chargers, one to each battery.

Or, some fit a smart charger on the LB, then a small b2b trickle to the starter. ( What I do)


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