Bavaria 40: Replace Bavaria charger with a Victron Multiplus - future proof?

[Krumelur]

My boat is equipped with the original battery charger SBC 501FR (40A).
I want to have a 230V inverter on board and instead of buying a separate device consider switching to a Victron Multiplus.

Here's what I wonder:

* Besides cost: Any reasons to not buy the most powerful one (Multiplus 1600VA with 70A charger)?
* For now, my batteries will be replaced with 2x 115Ah AGM but in the future I want to get LiFePo4s in there. The Victron would be able to handle these, I suppose?
* Victron's website says, the Multiplus replaces the older "Compact" models. Do you know what the (major) changes were? I wonder if I can find a used "Compact"?

[Yngmar]

The new Multiplus seems to be a complete redesign, the old series is still on their website so you can compare for yourself. Looks like they addressed one of the main critique points, which is that it was an enourmous, space consuming metal box that wasn't really suited to the small yacht market at all.

For sizing, you need to make sure your batteries can absorb the charge. AGM batteries typically shouldn't be charged at more than 0.3C (30% of total capacity per hour). With your bank of 230Ah, 70A charging current is just slightly over that limit, but definitely not going to be kind on them. Check your battery data sheet for the manufacturer's recommendation. For your current bank, the existing 40A charger is better suited and it would be cheaper to just add an inverter.

The Victron data sheets will tell you exactly what kind of batteries and what kind of charging regimes their units can supply.

[tiger79]

For sizing, you need to make sure your batteries can absorb the charge. AGM batteries typically shouldn't be charged at more than 0.3C (30% of total capacity per hour). With your bank of 230Ah, 70A charging current is just slightly over that limit, but definitely not going to be kind on them.

Charging current is determined by the batteries, and their state of charge.  Just because a charger is capable of delivering 70A doesn't mean that it will. With only 230Ah of batteries, charge current is likely to be much less than 70A, but the charger won't harm them.

[semaphore]

I suspect you can turn down the max amperage to suit the manufactures recommended charging current.

While not victron, I had my charger turned down with my previous batteries, but now at max with lithium I'm well within .5c of 550ah.