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Cheap 48V lipo battery charger?

justinm001

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Dec 18, 2022
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Anyone know of a cheap 120v ac to 48v dc charger with lithium profile I could wire up as a backup?

I don't think I'd ever use it but figured its good to have
 
I was hoping for something small and cheap like in case of emergency trickle charge or to help with precharging my inverters.

For my 12v system I have a little 10a one and it saved me in a pinch where my lithium batteries died and I needed to use my genny start battery for 12v loads so just plugged this in and disconnected everything else except my 12v loads. Kept me from needing to reprogram everything. Been using it for a couple weeks fine

TREE.NB 110W 54.6V 2A XLR Lithium Battery Charger for Electric Bike Mobility Scooter 48V Lithium Battery Charger XLR Connector https://www.amazon.com/dp/B08HVFVLRK?ref_=cm_sw_r_apann_dp_F0RWZ2X9YXPSHH0EGTPY
 
I was hoping for something small and cheap like in case of emergency trickle charge or to help with precharging my inverters.


TREE.NB 110W 54.6V 2A XLR Lithium Battery Charger for Electric Bike Mobility Scooter 48V Lithium Battery Charger XLR Connector https://www.amazon.com/dp/B08HVFVLRK?ref_=cm_sw_r_apann_dp_F0RWZ2X9YXPSHH0EGTPY

I use something very similar and think it’s good to have on hand for all the reasons you discussed.

An additional benefit is that if you over discharge and need to “wake up” the BMS to get a charge going these work for that purpose in my experience.

At around 3.41V per cell that is a bit low for a 16s LiFePO4 but will certainly get the job done.

I cut off the funky connector and put on anderson power poles since I have a bunch of adapters I have made with them to large alligator clips, MC4, etc.

Also note you can trim down your link to this :

 
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I was hoping for something small and cheap like in case of emergency trickle charge or to help with precharging my inverters.
I don't know your system. Just some curious of a couple of things.

-I don't see how this helps pre-charging an inverter Are you not using a resistor to pre-charge the inverter?

-Also, does a 2 amp battery charger meet you needs? It very well may, but 96 watts charging may just barely get above some parasistic loads.

IMO, even the AIMS charger pushing 17 amps into a 260 ah battery pack is not pushing a lot of power.
 
I don't know your system. Just some curious of a couple of things.

-I don't see how this helps pre-charging an inverter Are you not using a resistor to pre-charge the inverter?

-Also, does a 2 amp battery charger meet you needs? It very well may, but 96 watts charging may just barely get above some parasistic loads.

IMO, even the AIMS charger pushing 17 amps into a 260 ah battery pack is not pushing a lot of power.
No I'm not using a resister to precharge my SOK batteries have a precharge option and it works but I feel that it's much easier to precharge with solar pumping in so the charger will help. I figured if the batteries are at a charge voltage it's less amps plus the charger helps. Anything to help minimize issues precharging.

Also I think a 2amp charger would charge the inverter itself then I could just turn the battery on, right?

2 amps will keep the inverters on at least if not charge the batteries a bit. So if both my batteries are dead and my inverters lost charge having a small charger should let it turn back on and since my inverters are my ATS they're needed to get 120/240v power.
 
Your thread name lists Lipo, and they first post just states lithium. Can you be more specific on which chemistry you are using, or is it LiFePO4 that is mostly discussed on this forum?
 
If you have access to 120v, why don't you feed that to the inverter to wake it up? Chargeverter is fine for charging batteries at a fixed voltage.
 
I use a couple of 300w adjustable bench power supplies as chargers. They're about $100aud from either Amazon or ebay.

Eg. Set to 57.6v with a timer switch set to 2hrs.
 
Also I think a 2amp charger would charge the inverter itself then I could just turn the battery on, right?
I don’t know.

My massive spark came when I hooked the battery to the inverter. I made the spark go away by adding a pre charge resistor to the circuit that I switch on for a few seconds then take the resistor out of the circuit. I don’t know what happens when you hook a 2 amp inverter to an inverter.

If you try, I’d like to see a post.
 
I don’t know.

My massive spark came when I hooked the battery to the inverter.
I that is because the battery can dump 100+ amps instantly.

I made the spark go away by adding a pre charge resistor to the circuit that I switch on for a few seconds then take the resistor out of the circuit. I don’t know what happens when you hook a 2 amp inverter to an inverter.
A 2 Amp charger will only deliver 2 amps (more or less). It may spark. But nothing like a battery can spark.
 
I that is because the battery can dump 100+ amps instantly.


A 2 Amp charger will only deliver 2 amps (more or less). It may spark. But nothing like a battery can spark.
Exactly this. I also can have everything connected with power off then turn on just the charger to use 2 amps to charge the capacitors then turn on the batteries so there isn't any precharge needed.
 
Your thread name lists Lipo, and they first post just states lithium. Can you be more specific on which chemistry you are using, or is it LiFePO4 that is mostly discussed on this forum?
LiFePO4 batteries sorry for the confusion. Pair of SOK rack batteries to be precise
 
If you have access to 120v, why don't you feed that to the inverter to wake it up? Chargeverter is fine for charging batteries at a fixed voltage.
Because the inverter needs 48v to turn on so if my batteries quit working for some reason my inverter can't turn on.

Also my inverters need a minimum of 13.5A to charge the batteries which is a bit high if running off an extension cord or something if I'm at someone's house or using a 15a extension cord over long distances. I'd rather run a 2a 48v charger which will only pull 4ish amps to give it just a bit of charge and help boost the solar.

99.9% of the time the inverter is going to be charging the batteries. This is just for a backup if emergency situation or something else. Which is why I want a $50 charger and not a nice $500 one.
 
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