Looking for a 2 amp charger for LUNA battery to use with solar generator

[JonPaul]

I am eager to use the excess power I produce with my solar panel to charge my Luna battery. I am using the Goal Zero Yeti 400 AGM. The inverter maxes out at 2.4 amps and everything that LUNA sells for my typical 48V battery puts out 3 amps at a minimum. So I am looking for a really SLOW charger -- 2 AMPS, so I can ride on photons! Thanks for any advice!

[JonPaul]

Luna didn't have one in stock, so taking a chance with this one from Amazon. Conservative charging at 1.5 amps.

https://www.amazon.com/gp/product/B0753C35N8/

[ykick]

I would've considered something like this: http://www.ebay.com/itm/DC-DC-600W-1...sAAOSwkr5ZkLN8

Connected directly to the 12VDC port and adjusted up to the voltage you need and Amps the Yeti can deliver. Save a couple conversion steps....

[JonPaul]

Thanks so much. The Goal Zero staff suggested the DC port as well, but I don't understand DC to DC charging. Time to study.

[ykick]

It may be tricky to adjust for this application (Volt and Watt/Amp meter required) but overall much simpler and likely fewer "losses" compared to 12VDC Yeti battery > 12VDC-to-120VAC inverter > 120VAC-to-54VDC charger > 48V battery pack. And don't forget many eBike battery chargers don't like crude DC-to-AC inverters. Dunno the Yeti personally but it's something you may run in to?

[JonPaul]

I was looking for something with an enclosure and found what's below. The Yeti can provide 12V x 10A = 120W so I wonder if I this one that converts to 48V 2A would charge 48v battery? Thanks for all your help.

https://www.amazon.com/uxcell-Conver...dp/B01MTNLW8D/

[ykick]

No, unfortunately that device has no adjustments available and if it doesn't output around 54.6VDC you'll be stuck.

[JonPaul]

And of course I will need to attend to the battery while charging as the DC to DC converters may not have the same ability to shut down when the battery is charged as AC adaptors....

[ykick]

If adjusted correctly Amps/current merely stops flowing when the battery pack reaches the "adjusted" supply output voltage. For all practical purposes OFF...

And in some cases that may actually improve BMS balancing of the battery pack compared to some AC chargers which merely shutoff and never restart bulk charging once the BMS has bled down higher voltage cell groups.

[newbie123]

Just wondering what your solution was.... i have same issue... solar system inverter won't carry the surge load of charger and I need to be able to charge from remote location using my solar, plenty of power to spare if i can figure out issues. thanks

[JonPaul]

I purchased this AC adapter that charges at 1.5 amps. https://www.amazon.com/gp/product/B0753C35N8/

I also purchased the DC to DC converter that ykcik mentioned above but I haven't tried it yet. Over the holidays I will!

[newbie123]

Did the smaller charger work with y our inverter? That is my next step in the process, though charging DC to DC has appeal, I still don't quite understand it. It would be more efficient than multiple conversions.....

[JPLabs]

I am eager to use the excess power I produce with my solar panel to charge my Luna battery. I am using the Goal Zero Yeti 400 AGM. The inverter maxes out at 2.4 amps and everything that LUNA sells for my typical 48V battery puts out 3 amps at a minimum. So I am looking for a really SLOW charger -- 2 AMPS, so I can ride on photons! Thanks for any advice!

You can't just compare amps. Voltages are different. Use power. Inverter can output 2.4A at 120V, right? That's 288W. A charger which outputs 3 amps at up to about 55 volts, only needs 165W or so. Steady state, your numbers should work.

If inverter won't run charger at all, probably due to high initial current spike.

[Joe Motocross]

I am also interested in charging from solar. I have two 6v deep cycle golf cart batteries that I charge via solar in my pickup camper. I also own a pure sine wave inverter.

What do you guys think of a set up like this?

Two 6v inline batteries (=12v)-->Aims 1500w pure sine wave inverter-->Luna Mini 52v charger-->52v 18650 ebike battery

Probably not the most efficient but seems like it would safely work until I hear of a good DC to DC charging method.

[Joe Motocross]

Sounds like I found an answer to my question in another thread: https://electricbike.com/forum/forum...fied-sine-wave

From folks experience with lower wattage modified sine wave inverters, my 1500w pure sine wave inverter should work just fine. Overkill.

[dwhitfield]

Just charge 52V ebike battery directly with 12V solar panel with something like this: https://www.youtube.com/watch?v=Yx7m5ij14M4&t=6s

[Gr8fun]

The 7210 is inefficient. With 100 watt renogy panel and a genasun boost cotroller i get 1.4 amps charge.
With 160 watt i get 2.3 amps peak. Normally 1.9.to 52volt battery.. The 160 is to large to mount on my bike.
With the 7210 a i get .1.2 amps with the 160 watt panel. Mobile power generation is difficult but it works.

[JimmyN]

Anyone know where I can buy a couple of replacement charging connectors like the ones used on the X1? I need the male end that plugs into the battery.