Larger converter

[DavidM]

This topic may not be relevant for LL owners as the existing converter is big enough for most, but I have a friend with a large Class A motorhome who wants to upgrade his 25 amp no name converter to 75 amps or greater to more quickly charge his large 450 amp hour coach battery bank.

I know the brands Progressive Dynamics, WFCO and Inteli-Power. Anyone know anything about Powermax. It is prominent on Amazon but is almost certainly Chinese. Any experience with it? Any others?

David

[Merlin]

Your friend might want to consider Iota Engineering equipment when planning to use heavy duty power supplies/battery chargers with 75+ amps capacity on huge battery banks. I use Iota equipment in renewable energy installations and can vouch for its quality and ruggedness. One like the 75A model linked below would take some extra effort for installation, but could be worth it. Folks do install them in RVs. Iota also makes a 90A model. They do a fine job charging batteries and being a power supply and you can also buy an add-on module for even better charging characteristics. I'm sure you realize equipment made for that kind of power can't be wimpy construction or improperly cooled.

https://www.solar-electric.com/iota-engineering-dls-75-x-battery-charger.html

One further thought is to check out Xantrex equipment. I use and like their Prosine line of inverters and I know they recently came out with their Freedom line of battery chargers for RVs. However, I've not used their battery chargers so I can't vouch for them.

[DavidM]

Merlin:

I was hoping to hear from you on this subject. I have read about IOTA chargers. They need the IQ4 option to make them a 3 stage charger, otherwise they are a fixed voltage power supply, right? Is the new DLS-X model a significant improvement over their former DLS model. The new X models are actually a little cheaper than the older ones.

I assume that the extra installation effort you talk about is that the 75A model requires 18 amps AC which is more than a standard 15A outlet circuit can supply. The 55A model can plug right into a 15A outlet.

It would be better to go with the 75 or even the 90 amp model because the whole point is to minimize generator running time, but that will require a dedicated 20A or 30A breaker and 12 or 10 gauge wire. Don't know if there is room on his electrical panel for another breaker. With 450 AHs of coach battery capacity he will be well under the 25% rule of thumb limit for FLA batteries with 90 amps of charger capacity.

Also another EE question for you. Chargers have horrible power factors which is why they pull so much current. Will this much power factor affect a 4 KW generator when you are pulling 22 amps out of a total genset capability of about 35 amps?

David

[Merlin]

The specs of the new X series Iota do appear to be an improvement. And, yes, they do need the X series adapter to be a multi-stage battery charger. The extra effort is in making sure they use a 20A 120V supply/outlet. either with a generator or with wiring in the camper. And a BIG wire from the charger to the battery bank!

Interesting and good question about the power factor. The short answer is I don't know! I would guess that a 4Kw genset is fine for the application, but it's a load.

[DavidM]

Thanks for the advice. On a former boat I had a 3.5 KW diesel generator and a 100 amp Xantrex/Freedom inverter/charger. The charger would pull about 17 amps when the batteries were a little low and that didn't seem to phase the generator. But it had a heavy 5 KW generator end. I suspect the RV generator isn't as robust.

So, we will give it a try with one of the IOTA DLS-X models with the IQ4 adapter.

David