AC Battery Chargers

[GoingMobile]

I want to add an inverter to my electrical system. I have looked at stand alone inverters and also ones that are inverter charger combined units. I do want to have a way of charging off of AC when available. If I were to go with a stand alone inverter, What functional considerations should I be aware of and any recommended brands or models of stand alone AC chargers?

 

[AmargosaWayne]

Your battery bank is which chemistry?

I have lead acid batteries.
Things may have changed since 2015, when I purchased the two chargers that I own, a Progressive Dynamics 45A and a Boondocker Powermax 100A. I have not had any issues with either charger.

 

[GoingMobile]

Your battery bank is which chemistry?

I have lead acid batteries.
Things may have changed since 2015, when I purchased the two chargers that I own, a Progressive Dynamics 45A and a Boondocker Powermax 100A. I have not had any issues with either charger.

LiFeP04 Lithium batteries.

 

[bluegoatwoods]

I am no expert. Full disclosure.

But....that said.....I tend to dislike appliances which combine more than one task into one piece. One reason being that....in your case........if your inverter gives up the ghost, then you must replace both your inverter and your charger. So I would recommend a stand alone charger and a stand alone inverter. I might recommend more than one inverter.....in descending sizes........if your rig will be using large electrical loads. Microwave? (Pure sine wave inverter, then) Coffee maker? If you'll run stuff like that then you might want a large inverter plus a small inverter to run just a few lights. Or other small load items.

For Life PO4 batteries I've heard that the optimum charge rate is about 30-40%.....in Amps......of the total Amp/hr of the battery. So one would want a 30 Amp charger for a 100 A/H battery. Once again, I don't know this for any sort of hard and fast fact. This is what I've heard and it sounds credible.

 

[frater secessus]

I tend to dislike appliances which combine more than one task into one piece.

Preach, brother!

For Life PO4 batteries I've heard that the optimum charge rate is about 30-40%.....in Amps......of the total Amp/hr of the battery. So one would want a 30 Amp charger for a 100 A/H battery.

If we are connected to shore power we can assume being in place for at least a few hours If so, even lower charging rates are possible and likely helpful. More thoughts on this below.

If I were to go with a stand alone inverter, What functional considerations should I be aware of and any recommended brands

Unless you are running purely resistive loads (hot plates, whatever) I'd look for:

• continuous draw wattage about 2x your biggest load{s}
• pure sine wave instead of MSW
• user-serviceable fuses

If the inverter is to be left on 24/7 then low parasitic draw and/or the presence of an energy-saving mode are more important. If turned off when not in use then no biggie.

or models of stand alone AC chargers?

For shore power charging LFP (maintaining, really) I'd pick out a dumb converter (or 12v power supply) that puts out ~13.2v (13.0-13.4v) For weeks/months on end I'd lean toward the lower end. IMO C/5 current (20Ah for 100Ah of LFP) would be optimal assuming it can keep up with loads.

These voltages may seem low* but the bank does not need to be (and does not like to be) fully charged while on shore power. Normal forms of charging (solar, DC-DC, whatever) can fully charge when that's needed.

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* because the standard charging recommended charging voltages are, IMO, counterproductively high.