Choosing a 100 Amp Lithium Charger for an RV

[hlrosenberger]

I'm looking for the best 100 AMP lithium battery charger. I've looked at PowerMaxx PM3-SME 100 amp charger, and the GoPower GPC-100-MAX. I know Victron is the top of the line, but so expensive. Anytime care to comment? Does anyone have either the PowerMaxx or GoPower chargers?

 

[SargeW]

Are you looking for a stand alone charger, or is it going to be built into the RV as a converter charger?

 

[hlrosenberger]

This is for an RV. What is the difference between a converter (120 Volts to 12 Volts) and a battery charger (also 120 Volts to 12 Volts)?

 

[SargeW]

A converter is generally hard wired in and will cost quite a bit more than just a stand alone. You can find many stand alone chargers on Amazon, but many are cheaply made and do not deliver the rated performance. I bought one when I was upgrading to Lithium and needed to individually charge 3 Lithium's to 100% charge before installing them in the rig for the first time. The charger failed all 3 times and would not charge to 100%.

The point is that if it's a one time use, you may get by with an inexpensive charger. If you want it for the long term, spend the money for quality.

 

[garyb1st]

My experience is similar to the Sarges. I charged mine initially with a 5 amp Battery Tender, a unit that can be programmed for lithium, lead acid or agm. It is a slow process. In my case I left the charger on overnight and assumed the batteries were fully charge the next morning. However, I really don't know for sure or how to determine that.

The only time I've ever since more than 13.3 or 13.4 volts is when I checked the voltage after installing my new converter. The converter is a WFCO-AD. A converter advertised to auto detect, (AD) the chemistry of the battery and charge accordingly. It replaced a 3 year old WFCO-AD, that as best I can determine never charged in the Lithium mode. The replacement which I installed a month ago brought the batteries to 14.5 volt when I installed it.

Before buying the new WFCO AD, I bought a $55.00 Schumacher portable battery charger. It had a lithium profile but for whatever reason, it wouldn't charge the batteries. Based on my experience, I suggest you not waste your time and buy a standard Converter Charger.

 

[Gary RV_Wizard]

This is for an RV. What is the difference between a converter (120 Volts to 12 Volts) and a battery charger (also 120 Volts to 12 Volts)?

Mostly a matter of the design for an intended usage and the type of duty cycle. First, a converter per se is not a charger - it is designed to produce voltage regulated to a narrow voltage range, typically about 13.1-13.3v, and continuously supply its rated amperage, indefinitely if needed. It's an electronic battery. Most RVs utilize a combo converter & charger, which actually produce two different outputs, i.e. the converter described above plus a higher, more variable voltage designed to efficiently charge a battery. And the charger output is managed to produce optimal charging rates that vary with the battery state of charge. Charging voltage is higher than what a battery or converter produces on its own. If you read the specs on that Powermax model you mentioned, you will see that the converter output is up to 100A continuous while the charger output is 100A short burst but either 10A or 40A in longer term charging modes.

Portable battery chargers rarely have a converter mode and are strictly chargers. They typically have a quick-charge mode to quickly bring a battery to a usable state plus a slower charge model that is more optimal in terms of battery life.

 

[Kirk]

Portable battery chargers rarely have a converter mode and are strictly chargers.

And that is the reason for the large price difference.

 

[John From Detroit]

And that is the reason for the large price difference.

I got one around here I got when my Converter died that has half a converter mode.

It will charge. then when full go to "Float" and stay there... Unless I manually reset it.

IT brough the house batteries back and worked (with the odd reset) till drove to Marshall with the towed and brought back a new, rebuilt 9180 and hooked it in.

Still got it

 

[PancakeBill]

There are wFCO converter chargers that sense the battery type and some where there is either a jumper or switch setting. Mine senses. WHen I bought it had LA batteries but knew I would switch over to lithium, so bought this one. When charging lithium it has a different profile.

So with batteries connected, when plugged into AC it will charge batteries as needed and provide filtered 12vDC to house circuits, it also passes aC thru breakers to items like fridge, mcrowave AC And water heater.

Why do you think you need a 100 amp charger?

 

[Isaac-1]

Keep in mind that a 100A converter will draw close to 1,800 watts on the AC side, which may overload a 30 amp RV hookup if you are running any other high draw load, such as an air conditioner. Note 30 amp RV outlet is only good for 3600 watts of power, 1,800 for the converter, plus another 1,500 or so for the air conditioner does not leave much for everything else.

 

[John From Detroit]

This is for an RV. What is the difference between a converter (120 Volts to 12 Volts) and a battery charger (also 120 Volts to 12 Volts)?

Technically a "Converter" Converts AC to DC, Filtered and regulated at a specific voltage (say 13.6) What is put in RVs' is a "Converter/Charger" this is (now days) a "Smart" Device that monitors system voltage and will put out a higher voltage (Say 14.6. example only) to charge and possibly to "Desulfate" or "Equlize" battery cells. Very good products. They rapidly charge, Then slow down to "Top off" and if needed go back into fast charge mode automatically.

Battery chargers come in two or three types
Fast chargers may well pop out 100 amps. but for a period of time. (Say 30 minutes)

Old fashion charge slower (say 10 or 20 amps) but know not when to stop

These also do not "Filter" so you get half wave AC not true DC. (Very nasty if you have electronics depending on clean power)

Then we have "Smart Chargers" These start fast, then slow down or stop.. But do not monitor or automatically switch back.. they may have SOME filtering but likely not on the charge lead. Though at 20 amps the batteries make real good filters (or did for me)

My question is this: DO you NEED 100 amps? or could you get by with say 60

Takes a bit longer to charge 'em up but if you never draw 100 amps. you don't need 100 amps and amp$ cost $$$$. And though I do not know enough about LiFePO4's most batteries like a slower charge.