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Should I get a lifepo4 battery charger?

TacoBravo

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Joined
Dec 28, 2021
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Hello,

As this being my 1st system, should I purchase a battery charger? I have 2 100ah lifepo4 chins batteries that state they are 50 percent charged when shipped. A battery charger seems like another purchase when the solar panels should charge the batteries. But it seems like something that you should probably have in case of emergency.

Also, I'm thinking i would need to purchase a dedicated lifepo4 charger to get the right voltage. can you buy other chargers to charge lifepo4 that aren't as expensive?
 
IIRC any of the smarter chargers that have settings for AGM will get you to 98% in time, but if it's an option to get a nice high amperage one that's built for it then it's always a good idea.
 
charger all AC to DC, means most time ,you have AC power, if you mostly no have AC power ,no need charger. i thinking that is why your system no together with it
 
Hello,

As this being my 1st system, should I purchase a battery charger? I have 2 100ah lifepo4 chins batteries that state they are 50 percent charged when shipped. A battery charger seems like another purchase when the solar panels should charge the batteries. But it seems like something that you should probably have in case of emergency.

Also, I'm thinking i would need to purchase a dedicated lifepo4 charger to get the right voltage. can you buy other chargers to charge lifepo4 that aren't as expensive?

Do you have a solar charge controller for between the solar panels and the battery? It isn't clear and I thought it would be good to make sure.
 
Do you have a solar charge controller for between the solar panels and the battery? It isn't clear and I thought it would be good to make sure.
The items that I have purchased so far are:

1. 4 renogy 100w 18.6v solar panels
2. 2 100ah chins lithium batteries
3. giandel 220 watt inverter
4. epever tracer 4215bn 40a 150v
5. 50amp circuit breaker
6. 200amp fuse

I haven't started to put anything together yet. I still need to purchase wires, connectors, bus bar, misc? I plan on following will's beginner 400 watt video and blueprints. But I'm welcome to any suggestions as I feel a little overwhelmed at the moment. I have no electrical experience and so some of it seems like a foreign language. right now i'm just watching electrical tutorial videos and rewatching will's video/blueprints so hopefully I don't burn anything down. I'm not in a particular hurry and just want to get it right.
 
It depends on why you have the solar power. If it's just for fun, then you don't need a charger. If it's to power essential loads, then yes, you do.

The good news is that unlike lead/acid the lithium batteries don't care if they're kept at a relatively low state of charge for extended periods. It's ok for them to be at 20 or 40 percent charge, whereas that will kill lead/acid batteries quickly. You don't have to charge them, but if you want power on a dependable basis you'll want to have some way to charge them besides solar, depending on. your loads and weather. Most larger inverters have chargers built into them for just that reason. Here in Oregon in the winter my lead/acid bank gets a boost from the inverter/charger every now and then to top it up when we don't see the sun for a week or two.
 
@TacoBravo, is this a standalone system or is it going into an RV? You probably won't make use of a charger with off-the-shelf batteries. It could be used for those batteries should something go wrong, but that's a long shot.
 
@TacoBravo, is this a standalone system or is it going into an RV? You probably won't make use of a charger with off-the-shelf batteries. It could be used for those batteries should something go wrong, but that's a long shot.
This is for my house. I will probably power my computer with it to get some use and savings out of it but it is mostly going to be for backup power or emergency use.
 
Thanks everyone

Ok, so it sounds like I shouldn't really need to have a charger. My inverter doesn't seem to have built in charger but if I do decide to get one as backup I can get a cheaper smart charger with litium option rather than a dedicated lifepo4 charger. And if the batteries are charged @ 50% upon shipping and there is and natural 5% loss every month, I should have around 6 months to finish system before I should start to need a charger.
 
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In my RV trailer my LiFePO4 batteries have been charged from shore power only a hand full of times. None of those times have been necessary. It happened only because I was connected to shore power or I fired up the onboard generator to do other things.

I do have a desktop power supply that I used to top balance my cells. But that doesn't apply to you since you have off-the-shelf batteries.
 
You can use a charger to have the battery charged up to 100% at any necessary time; specially when you want to make a test (eg. capacity test).

If you do not want to spend a lot of money on it you can buy the cheapest Lifepo4 charger on Aliexpress for about 5 euros. It has a DC connector so you may have to customize it to your battery input unless it already has DC connector input. I personally bought a DC plug for 50 cents (male + female) and used only the female to receive the input from the charger (male). My battery is 60Ah 12V and the cheapest charger is 2 Amp rated, so I need just 38 hours to charge the battery. 15 euros can get you the 5 Amp version; also interesting.
 
Thanks everyone

Ok, so it sounds like I shouldn't really need to have a charger. My inverter doesn't seem to have built in charger but if I do decide to get one as backup I can get a cheaper smart charger with litium option rather than a dedicated lifepo4 charger. And if the batteries are charged @ 50% upon shipping and there is and natural 5% loss every month, I should have around 6 months to finish system before I should start to need a charger.
Some of the smart folks suggest fully charging your batteries with LIFEPO4 specific charger before putting them into service. Sounds good to me.

I believe your 12/24 volt charge controller will allow you to charge your batteries perfectly without spending any more money as long as you have 12 or 24 volt batteries.

The way I understand the subject, all you need to do is charge them individually to full capacity prior to connecting them together.

Obviously this is not a plug & play setup. Your solar panels will be supplying the power. If you don't mind connecting and disconnecting, you can save some money and precisely control the charge while familiarizing yourself with the controller.

I think I got that correct, maybe someone will chime in and give it a Yea or Nea.
 
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