48v Battery Charger?

[Lt.Dan]

Hey guys, I'm looking for a backup battery charger for my RV, and I've run into atleast 1 problem with every charger I find!

AIMS 48v Charger is nice, especially with variable amperage output, but it has a terrible 80% efficiency, and is only 18.75a output, for $300! I also don't know what the max charge voltage is?

Signature - EG4 48v Charger is nice too, and has a good 25a output (pretty much max for a 120v receptacle). But it charges to 58.4v, which is 3.65v per cell. No problem if you have a battery perfectly balanced to .001v and dont care about holding that voltage way too high. I even called Signature solar and they told me thats correct, and there is no changing it, and no ordering a custom charge profile.

Daygreen 48v Charger is the best in the lineup because of price ($100!!) and output. Rated at 30a and 93% efficient is nice. But I dont know the max charge voltage, and they are out of stock. I've emailed them several times, and the only response I've gotten back is "How many do you need?". After responding with, just 1, I never got a response back.

Can anyone share any other good 48v chargers? I'm specifically looking for one to get the full capability of my 1800w Ryobi Backup Generator.

 

[Samsonite801]

Well I bought the AIMS one, only using it for benchwork and testing my banks, since I don't have my real system with the MPPs live yet. I figured it would be enough power to charge by AC source if needed, I guess I'm not too worried about the 80% efficiency, since it is more of a bench device for working on a bank when I don't have inverters plugged in yet.

Because after I get the inverters all plugged in, it will charge on solar via the MPPT chargers, and they have generator inputs for AC charging, so I probably won't ever have a need to use the AIMS for anything in normal use, will be more like an alternate or emergency means of charging a 48v bank, so efficiency not being perfect doesn't really bother me too much.

https://www.aimscorp.net/documents/CON120AC3648VDC.pdf

 

[Lt.Dan]

Well I bought the AIMS one, only using it for benchwork and testing my banks, since I don't have my real system with the MPPs live yet. I figured it would be enough power to charge by AC source if needed, I guess I'm not too worried about the 80% efficiency, since it is more of a bench device for working on a bank when I don't have inverters plugged in yet.

Because after I get the inverters all plugged in, it will charge on solar via the MPPT chargers, and they have generator inputs for AC charging, so I probably won't ever have a need to use the AIMS for anything in normal use, will be more like an alternate or emergency means of charging a 48v bank, so efficiency not being perfect doesn't really bother me too much.

https://www.aimscorp.net/documents/CON120AC3648VDC.pdf

View attachment 58955

Thanks for that picture! Looks like the AGM Fast 48v setting is almost exactly what I want at 57v.

 

[Lt.Dan]

Looking at one on AliExpress right now too. 20a with a customizable output voltage, for $112. Not bad.

 

[Lt.Dan]

No other recommendations?

 

[cass3825]

Ordered this one on AliExpress, still waiting on delivery…

 

[Lt.Dan]

Debating between a Riden 6018 on Amazon for $200 right now, the Aims 18.5a charger for $275+shipping (same charging capacity as the Riden, but atleast with the Riden I can top balance more cells that I have on the way) Or the Signature solar EG4 25a charger for $259.

I keep scouring Alibaba and Aliexpress, but I keep turning away from them, I would rather buy from someone a little more trusting I guess.

 

[time2roll]

Backup? Consider a Meanwell adjustable battery charger.

 

[RCinFLA]

If you plan to run from generator you might also want to look at their power factor rating.

An inverter-charger may not be much more expensive than a charger only. You then also have an inverter backup.

 

[jwelter99]

My suggestion is not a cheap solution. Victron Skylla 48/25 or 48/50. You need 230V input for them but they are a solid product. The 25A is $600 or so.

 

[Lt.Dan]

Backup? Consider a Meanwell adjustable battery charger.

I will look into them, thank you!

If you plan to run from generator you might also want to look at their power factor rating.

An inverter-charger may not be much more expensive than a charger only. You then also have an inverter backup.

Is the power factor something that a typical battery charger states? Is nothing I've ever seen on states for one.

Not a bad idea for the inverter charger, ill look into that as well.

My suggestion is not a cheap solution. Victron Skylla 48/25 or 48/50. You need 230V input for them but they are a solid product. The 25A is $600 or so.

A charger with 230v input is not of any use for me. The only time I'll need this charger is when 220-240v is not available, and I will need my small generator (110v).

If I have 220v-240v available, then my inverters act just like I'm at home.

 

[RCinFLA]

If charger has power factor correction they usually state power factor. If not, they don't specify anything.

If just rectifier-filter capacitor for AC-DC conversion the power factor will likely be in 0.6-0.65 range. V*A load on generator will be 160% of actual wattage.

Generators, transformers, and inverters are rated for VA, not watts, because that is what their internal losses are determined by. The worse the PF, the higher the peak load current for given amount of true wattage load.

When PF = 1, VA and watts are equal so there is usually a little astersis somewhere in specs when they claim xx wattage rating indicating wattage rating is based on PF of 1 for max wattage load claim.

Most newer computer power supplies have power factor correction circuits included. It is a boost DC-DC converter circuit between rectifier and high voltage DC filter capacitor to make the charge current to filter cap follow a sinewave shape. It would be same for a PF corrected charger.

A hybrid inverter-charger that sync's inverter to incoming AC has a good power factor for charging.

 

[Lt.Dan]

I guess that would make sense with my last experience with my generator, which has lead to me trying to find a standalone charger.

When I set my LV6548s to charge at 20a (10 amps each, 1024 watts total), my generator would overload (even though it was rated for 1800watts continuous). Maybe the LV6548s have a poor power factor?

 

[time2roll]

1800 watts rated may only put 20 amps into a 48v battery. At least I understand 1800 will put max about 80 amps into a 12v battery and yes that is with no PF correction. You might get 25 with PF correction. Meanwell is PF corrected afaik.

 

[Lt.Dan]

After looking into the mean wells and getting lost on how many they offer, I can't figure them out.

I think I'm going to get the EG4 charger and just hope it doesn't overload my generator and doesn't try and over charge the battery. Signature assures me they have never had it overcharge a battery somehow? Wills last video he said he's got the exact same one and he loves it.

 

[chrisski]

I am getting the 24 volt AIMS model for my 24 volt build. I have the same concerns I think you do, will it overload my generator or overcharge my battery?

For the overcharging the battery, the only time I will ever use it is bad weather days when I need to recharge the batteries when solar won’t cut it. I’m just going to shut it off before its a problem and switch back to the inverter. I’ll be checking the shunt for SOC until its above 90%, then the generator will go off.

When I’m in the campground with shore power, I don’t turn the converter on. The measly amount of DC I use is easily replaced from solar. It’s just not being comfortable with the float or charge voltages.

If you use this in float mode, I’d like to hear how it works for you.

 

[time2roll]

After looking into the mean wells and getting lost on how many they offer, I can't figure them out.

Yes after closer look there is not as much in your range with 48 volts.
Maybe the RSP 1500 but does not seem like plug and play. Although it should run on 1800 watts and give 32 amps if you get it dialed in.

https://www.meanwellusa.com/webapp/product/search.aspx?prod=RSP-1500

And it is pushing $300 at the level you want. https://powersupplymall.com/collect...p-1500-48-power-supply-1500w-48v-32a-parallel

Some lower cost but are going to be slow at 200 - 600 watts. https://powersupplymall.com/products/meanwell-se-200-48-power-supply-200w-48v-4-4a

Mostly I have seen these used for 12 volts.

 

[Lt.Dan]

Well I took the chance and made my first purchase on Alibaba.

This product is no longer available.

This product is no longer available.

www.alibaba.com

Wish me luck. I should receive around end of this month, I paid for faster shipping.

 

[eabyrd]

You can look into a V5 AutoGen 48v DC Generator which can charge any 48v battery bank chemistry upto 70amps max.
Gasoline or LPG with a very small form factor and weight. Autostart and stop, wifi connectivity and able to control/monitor via mobile phone app.
Here is a link for your reference

V5 AutoGen 48v DC Generator | Smartest 48v DC Generator

V5 AutoGen Automatic Start 48v DC Generator. Designed to automatically startup and charge low battery banks. Accessible over wifi through our ...

dcautogen.com

Short video here

Wow, they’re proud of em

 

[Lt.Dan]

Well I took the chance and made my first purchase on Alibaba.

This product is no longer available.

This product is no longer available.

www.alibaba.com

Wish me luck. I should receive around end of this month, I paid for faster shipping.

Just got notification that it shipped out today from Shenzhen. Very delayed compared to the 5 days the listing said it would take. We'll see how long it takes to get here to California now.