B2B Charger Sizing

[Next Stop]

One for the battery wizards...

I have a single Leoch Adventurer 130ah (116ah C20) AGM battery.
200w of solar running through a Victron 75/15 MPPT Charge Controller.
I want to install a B2B charger (A Victron one, as the rest of my gear is Victron and I trust it) as during our last trip in October the sun wasn't really charging the battery much and we had to hook up on a few occasions.

But, what size should I be looking at, the 18a or the 30a?

I've read a lot of conflicting information on the web, I thought I had made my mind up, but I spoke with a local installer yesterday and he said to go for the opposite of what I picked.

Yours,
Confused

 

[ivorantony]

With the price of lithium dropping, I would be replacing the AGM battery and fit a 50 amp battery battery charger,

 

[Guigsy]

I've got all Victron gear. I kept to a 30A B2B charger so I could keep the wiring simple. But the Victron Orion 30A gets pretty hot because it's not very efficient. And it's pretty dumb, so there's almost no benefit to it being app connected. So I got the Votronic 30A instead. It's cool, small and easy to wire in.

If you were to get a bigger battery in the future, the Victron 50A is a much better unit than its 30A sister, more efficient and smarter. But not worth it with AGM.

 

[Speve]

I will be taking out my Victron Orion B2B and replacing with the 50a victron B2B in the next week or so if you are interested PM me and we can sort something out it’s only about 12 months old only replacing as I have lithium and it’s not up to keeping it topped up quick enough.
It’s the Victron Orion-tr smart 12 12 30

 

[Lenny HB]

If you fit a Victron Orion XS it's 50 amps but programable for 1 to 50 amps. You could set it for 25 or 30 amps then if you change batteries or at a second one you have the option of changing the charge rate.

Battery spec should give the max charge rate it can accept.

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[Googlebot]

I have the 50 amp Victron, excellent bit of kit!

Wouldn’t use anything else, the lower output ones are supposed to be a bit rubbish.

 

[peterc10]

I've got all Victron gear. I kept to a 30A B2B charger so I could keep the wiring simple. But the Victron Orion 30A gets pretty hot because it's not very efficient. And it's pretty dumb, so there's almost no benefit to it being app connected. So I got the Votronic 30A instead. It's cool, small and easy to wire in.

If you were to get a bigger battery in the future, the Victron 50A is a much better unit than its 30A sister, more efficient and smarter. But not worth it with AGM.

Another vote for the Votronic 30A B2B. Had it 3 years now and it has performed as it should. I agree with others that you should go for Lithiums and bin the AGM. Again I did that 3 years ago. I had 2 x 85Ah AGMs and were replaced with 2 x 120Ah lithiums which are exactly the same size as the AGMs and provide over double usable charge. And they were 50% lighter that the AGMS, so added more payload.

 

[LostInSpace]

But, what size should I be looking at, the 18a or the 30a?

Our new Hymer came from the factory with a Schaudt 121545 set to 70 amp output. (with 80amp wiring direct battery to battery and fuses)

So as others have said, get one at least capable of 45/50 amp output. But, do check that you you have the wiring capable of supporting whatever output you choose.

But, also, remeber that you can run another one in parallel at a later date. with wiring of its own if needed.

An 18amp B2B will probably only run the fridge and put nothing worthwhile into the battery.