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A high amp power supply for lifepo cells

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SherylinRM
(@sherylinrm)
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I have bought a LOT of power supplies and they all break after 3 or 4 months. I am sick of it.

I have some 24 volt, 280 Ah 8 cells of lifepo batteries. I would like to charge them up to the 29.2 or any variable of that, with at least 30 amps. But more up to 1,000 watts which is the limit of my wall outlet.

So anyone up for the challenge?

Quality high grade components only of course. I want this thing to last for years if possible. πŸ™‚

Thanks guys. πŸ™‚


   
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Ron
 Ron
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What is the configuration of the cells, ie how many in series and how many in parallel and what is the voltage and AH of a single cell. Also are the LiPO or some other chemistry?

Β 

"Don't tell people how to do things. Tell them what to do and let them surprise you with their results.” - G.S. Patton, Gen. USA
"Never wrestle with a pig....the pig loves it and you end up covered in mud..." anon


   
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SherylinRM
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I said 8 cells.

I said 280 Ah.

I said 29.2 volts [so obviously all 8 in series].

I also said lifepo.

The only thing I didn't say was 29.2 divided by 8 equals 3.65 volts.

Maybe actually read what is said would help?

I don't know, just an idea.


   
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Ron
 Ron
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@sherylinrm Since I don't know of a 3.65V Lifepo battery I was confused. So if 8 in series then each cell is 280AH and some voltage is 3.65. If you meant LiFePO4 then you should have said as much.Β 

Now maybe we can start over.

You have 8 batteries in series. Chemistry LiFePO4, Absorb voltage unknown my LiFePO4 fully charged is 14.2 with absorb set at 14.4, AH are 280 so each battery weighs about 84 lbs since my 100AH batteries weigh 32 lbs each.

I did read, I am according to some on this forum the resident battery expert. If you want help, it works better if you respond to the questions in a civil manner.

Are these the new Battleborn big batteries, 280AH?

"Don't tell people how to do things. Tell them what to do and let them surprise you with their results.” - G.S. Patton, Gen. USA
"Never wrestle with a pig....the pig loves it and you end up covered in mud..." anon


   
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Will
 Will
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@sherylinrm

Sounds like you need to buy better quality chargers.

Experience is what you get when you don't get what you want.


   
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Ron
 Ron
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@sherylinrm What exactly do you mean by break, I never heard of a charger breaking, burning out maybe. Just make sure anyone who tries to design a charger for you understands it's LiFePO4, it's a '24V' battery, the absorb should be 28.4 to 29.2 with 28.8 being the safe mid point. If you buy one a Victron is the gold standard, mine is 120A. Do you have a shunt and BMV already? That is what will control the charger. I am attaching a screenshot of my battery management controller for a 600AH 12V Battleborn system. Just double the voltage numbers for 24V. If you want to build your own, you will need to figure out how to compute Peukert, tail current, efficiency etc. I suspect there will be a free library somewhere. I do know that Victron's 'brains' software which does everything is *nix based so open source.

IMG 7046

Β 

"Don't tell people how to do things. Tell them what to do and let them surprise you with their results.” - G.S. Patton, Gen. USA
"Never wrestle with a pig....the pig loves it and you end up covered in mud..." anon


   
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SherylinRM
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@will Gee you think? If you know of any, rather than not being helpful. Maybe gives links to good ones?


   
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SherylinRM
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@zander Burning out is broken. Or at least it means that to me.

Also the voltages would go up and down AS it is charging. Something that is very dangerous.

I have a 300 amp shunt. Overkill I know. Not sure what a BMV is though.

As for Victron. I don't like that they monitor and track you etc via the phone app which uses data and I have no data on my phone. So it won't use my phone.

Peukert is for lead acid not lifepo cells.

I think I figured it out. BMV Means BMS, correct? Typo I suspect.

And the BMS does not control the charger. At least no charger I have ever heard of or seen in the last 40 years. It does monitor batteries [hence the name BATTERY management system]. But not the chargers. It can stop the flow of electricity from a charger. But that is not controlling a charger though.

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As for figuring it all out to build my own. If I could do that I would not be here asking for a circuit to build.

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Um thanks for your "help?

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Will
 Will
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Posted by: @sherylinrm

@will Gee you think? If you know of any, rather than not being helpful. Maybe gives links to good ones?

Well, since you haven't told us what makes, models and manufacturers have failed you, it's a little hard to make a useful suggestion for fear of just repeating one of your previous errors.

However, I can see that this will be a fruitless discussion, so ... hope you find something suitable.

Experience is what you get when you don't get what you want.


   
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SherylinRM
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@will Well why would you mention ones that don't work then? If you actually knew of any that were exceptional you would mention them.

But you need an out so you dump on me instead.

Thanks for the heads up into yourself though. Much appreciated. 😀Β 


   
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SherylinRM
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@zander I did respond in a civil manner to EXACTLY what you asked.

If I need to crawl and snivel though I refuse. Have a nice day though. You can ignore me. I replied to you according to the fact you ignored what I wrote is all.

If that offends you then PLEASE ignore me as I refuse to grovel because you are an "expert" in batteries but who can't even read a simple sentence.

Β 

Have a nice day now. 😀Β 


   
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SherylinRM
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Well this is not going well at all. Either the experts can't read. Or the lame blame others for their shortfalls.

I hope I can delete this.


   
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SherylinRM
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I can't find a delete button.

So everyone just ignore this post please and thank you. 😀Β 


   
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Ron
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@sherylinrm The BMV is what I showed you earlier, it's the Battery Monitor. NOT BMS. I bought my first BMV and shunt before I bought my first Trojans. if you are going to live your life based on who and what is tracking you then you are in for a lot of frustration. As a retired computer security guy, you don't know the half of it. Unless you have something to hide, just get on with your life, it's much ado about nothing. The bad guys want you to be stressed, think about it. NOPE, Peukert applies to ALL batteries although much less so to LI.

I doubt you will ever get any help given your attitude. Will is one of the most helpful guys on here and one of the friendliest. I on the other hand can be snarky.

People who come here with a solution in hand and then ask for help are bound to have some friction. If you know what you want (better quality charger) just go buy one and YES I recommend Victron.

If there was an unsubscribe option I would be using it.

Good luck.

"Don't tell people how to do things. Tell them what to do and let them surprise you with their results.” - G.S. Patton, Gen. USA
"Never wrestle with a pig....the pig loves it and you end up covered in mud..." anon


   
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Ron
 Ron
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@sherylinrm VICTRON

"Don't tell people how to do things. Tell them what to do and let them surprise you with their results.” - G.S. Patton, Gen. USA
"Never wrestle with a pig....the pig loves it and you end up covered in mud..." anon


   
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