Whats a good 48v battery charger

[severin20]

Aloha Fam,

Trying to help my friend get their battery bank charged from a basic gas generator.

It's a 48v battery bank 200ah, sealed lead acid batteries.

She does have solar but wants backup for extended cloudy days etc.

She already has a little gas generator. Dont know the specs.

To determine the charger size, do I take 120v from the generator and multiply it by the charger amps. Aka a 30 amp charger would charge 3600wh and the battery bank is 9600wh so charging would take 3 hours. Assuming the generator could handle that load?

Do my numbers make any since? And does anyone have a product recommendation for charging this battery bank off a generator. Something simple for intermittent use.

 

[Roswell Bob]

Aloha Fam,

Trying to help my friend get their battery bank charged from a basic gas generator.

It's a 48v battery bank 200ah, sealed lead acid batteries.

She does have solar but wants backup for extended cloudy days etc.

She already has a little gas generator. Dont know the specs.

To determine the charger size, do I take 120v from the generator and multiply it by the charger amps. Aka a 30 amp charger would charge 3600wh and the battery bank is 9600wh so charging would take 3 hours. Assuming the generator could handle that load?

Do my numbers make any since? And does anyone have a product recommendation for charging this battery bank off a generator. Something simple for intermittent use.

They almost make sense. A 30amp charger would be about 1500w. The product of the charger current and the pack voltage. The RMS input current of the charger should be matched to the generator. So a 30A charger would take about 200Ah/30A - about 6.66 hours to charge. Come back with generator spec/model and we can help pick out a charger.

 

[wtrey613]

Actually i have a similar question as well, i have a Honda EU2200 watt generator. its ac output is 120 Volts. 15Amps.
My battery is a 5.0Kw 48V 100AH.
So what kind of charger would i need and how long would it take to charge my battery from zero?

would this charger work as well?? 48V 35Amp charger

 

[Gone]

The one above is for lithium.

This one is popular for lead acid.

And a cheaper option (but no reviews).

 

[Roswell Bob]

I would consider a charger with PFC if running on small generator. Meanwell has some nice looking units. I cannot give recommendation, but plan on using one when my new cells arrive.

 

[severin20]

They almost make sense. A 30amp charger would be about 1500w. The product of the charger current and the pack voltage. The RMS input current of the charger should be matched to the generator. So a 30A charger would take about 200Ah/30A - about 6.66 hours to charge. Come back with generator spec/model and we can help pick out a charger.

Hi. It took me a while but finally got the generator info. It's a honda 2200. Here is the user manual. https://images.thdstatic.com/catalog/pdfImages/60/60b2d625-30a8-454e-a5d2-5465443f6906.pdf It says right in the manual that the DC out can only be used to charge 12v batteries and has no control for overcharging batteries etc. Is this enough info to determine what charger I need to get to charge batteries from the generator?

 

[Roswell Bob]

This generator is a 1.8kVA unit. A 30-35 amp charger would be about right. The charger below will do about 70% at 120vac in. They are normally run off of 240vac If you want to load generator fully then go for the 3200. What kind of loads will your friend be using? I use about 6kWh /day so this would run for about 3-4 hours on overcast day.

https://www.trcelectronics.com/ecomm/pdf/RPB1600.pdf

https://www.trcelectronics.com/ecomm/pdf/dbu3200.pdf

 

[Roswell Bob]

Actually i have a similar question as well, i have a Honda EU2200 watt generator. its ac output is 120 Volts. 15Amps.
My battery is a 5.0Kw 48V 100AH.
So what kind of charger would i need and how long would it take to charge my battery from zero?

would this charger work as well?? 48V 35Amp charger

It may work. It really depends on the design of the charger. I took quick look at link. Not much info available - no data sheet. I would tend to go for a charger that you can contol the current. If you get into a jam with the little generator then your only choice is to reduce the current. The Meanwell input current is matched to the generator as it pulls pure sinewaves and has programmable curves so that any battery chemistry can be charged.

 

[Supervstech]

Many inverters have a generator input to charge the bank, check to see if your friends inverter does.

 

[wtrey613]

Many inverters have a generator input to charge the bank, check to see if your friends inverter does.

So my Growatt 5000 ES, off grid has a generator input, but apparently you can only run your AC loads off the AC input (generator). you can't charge your 48V batteries off your AC input? I called signature solar who sold me the inverter. as well.

 

[wtrey613]

It may work. It really depends on the design of the charger. I took quick look at link. Not much info available - no data sheet. I would tend to go for a charger that you can contol the current. If you get into a jam with the little generator then your only choice is to reduce the current. The Meanwell input current is matched to the generator as it pulls pure sinewaves and has programmable curves so that any battery chemistry can be charged.

Got it, i will keep looking then for a 48v charger to use. thanks! ALso i have a growatt 5000 es, and the manual has a AC input to Battery mode, but apparently i dont think it stepps up the charge from 12v to 48V.

 

[Supervstech]

So my Growatt 5000 ES, off grid has a generator input, but apparently you can only run your AC loads off the AC input (generator). you can't charge your 48V batteries off your AC input? I called signature solar who sold me the inverter. as well.

Odd... my growatt style inverter charges great... maybe there is a setting to change?

 

[mesquito_creek]

My harbor freight predator 2000 connected to a signature solar EG4 25 amp charger to my 48v LifePO4 battery bank produces ~1000 watts of charging according to my Victron Shunt.

A honda 2200 is pretty comparable and will be the limiting factor on how much and how fast you can charge... I would be careful putting a charger over 25-30 amps for fear of overloading the generator and tripping the breaker, unless your charger will limit the output. The honda generator 120 ac plug is 20 amps and the output of the generator is 1.8 kva

 

[me3]

My multiplus 5k charges my 48v pack at 1900w, though the generator runs better at 1700w.
I also have an AIMS charger. It's crap. Equal amounts of Charge / Heat / Noise.

 

[LVLAaron]

AC Converter/Battery Charger 36/48V: The Inverter Store

Offering a large charging capacity, the AIMS AC Converter/Battery Charger 36V and 48V, 25/18 amps, handles multiple battery types across a range of applications.

theinverterstore.com

These are great standalone chargers. Variable output, so if you have concerns about load on the generator you can just turn the output down a little bit.

 

[me3]

AC Converter/Battery Charger 36/48V: The Inverter Store

Offering a large charging capacity, the AIMS AC Converter/Battery Charger 36V and 48V, 25/18 amps, handles multiple battery types across a range of applications.

theinverterstore.com

These are great standalone chargers. Variable output, so if you have concerns about load on the generator you can just turn the output down a little bit.

I have one of those. It's terrible.
Noisy, slow to charge and produces as much heat as is does charge. Always heat limiting it's output, with the fan going nuts.
It's in the same room I am.
Near match for the Victron color scheme. Not much else.

 

[LVLAaron]

Do you have the 12/24 or the 36/48 version? I have the 12/24 and it runs like a champ. Yes it has a fan but it outputs 75amps all day if I need it to.

 

[me3]

36/48
48v system

 

[Stewfish]

Aloha Fam,

Trying to help my friend get their battery bank charged from a basic gas generator.

It's a 48v battery bank 200ah, sealed lead acid batteries.

She does have solar but wants backup for extended cloudy days etc.

She already has a little gas generator. Dont know the specs.

To determine the charger size, do I take 120v from the generator and multiply it by the charger amps. Aka a 30 amp charger would charge 3600wh and the battery bank is 9600wh so charging would take 3 hours. Assuming the generator could handle that load?

Do my numbers make any since? And does anyone have a product recommendation for charging this battery bank off a generator. Something simple for intermittent use.

AIMS is working good for us - for future people doing research

 

[me3]

AIMS is working good for us - for future people doing research

It your fan noisy (fast speed)? And sometimes never slow down / shut off when charge finished (stay noisy)
At the full charge rate - how much heat comes out?
Does the charge rate slow down to about 50% after 30mins due to heat?