Any one maintaining a 48v LiFePO4 battery system made from four 12v 200A wired in series?

[portsample]

I am hearing the siren's call of cheap 12v 200A battery packs that can be had during Black Friday sales. I am interested in using four of these wired in series to create a 48v battery string. Once the packs have all been balanced by bringing to a similar charge state, how often does this typically need to be redone? Are there other potential hazards? Some manufacturers, (https://dakotalithium.com/product/dakota-lithium-48v-100ah-lifepo4-deep-cycle-battery-set/) sell packs of four 12v batteries with the stated intention that they will be wired in series to create a 48v source. Please advise. TIA

 

[sunshine_eggo]

The battery specifications must indicate that they can be wired 4 in series. Some can't.

Individually charge each 12V battery to 14.4V.
Wire all four batteries in parallel and charge to 14.4V, hold there for two hours.
Disconnect and wire in series.

Monitor batteries at peak voltage and confirm that all four 12V are nearly identical in voltage.

Consider something like this:

https://www.amazon.com/MAZAVA-Equalizer-Regulator-Batteries-Connected/dp/B09GLS1DVR

This will help keep the individual 12V at the same voltage.

 

[Crowz]

I am hearing the siren's call of cheap 12v 200A battery packs that can be had during Black Friday sales. I am interested in using four of these wired in series to create a 48v battery string. Once the packs have all been balanced by bringing to a similar charge state, how often does this typically need to be redone? Are there other potential hazards? Some manufacturers (https://dakotalithium.com/product/dakota-lithium-48v-100ah-lifepo4-deep-cycle-battery-set/), sell packs of four 12v batteries with the stated intention that they will be wired in series to create a 48v source. Please advise. TIA

I don't understand why you would want that. The one you linked is over $3000 for 100ah. The chins 48v 100ah with bluetooth I bought is less that $1300.

 

[portsample]

I don't understand why you would want that. The one you linked is over $3000 for 100ah. The chins 48v 100ah with bluetooth I bought is less that $1300.

That's not the one. That is just an example of a mfg selling 4 batteries for series wiring.

 

[Crowz]

I had looked into what your thinking of doing and one thing that made me not want to go that route was the bms.

The bms used in most of the batteries will and others have torn down goes down in amperage and quality with each tier you drop in price from what Ive seen.

So if you get down low enough in price the bms's can't handle any real life loads from what I could tell. To get a nice enough single 12v that looked like it could handle the load your back up to the same price as a 48v like I went with or even a server rack battery.

To me if you don't want to go the premade 48v battery route I'd do a diy multi cell build which is going to be cheaper than even the cheapest 12v battery.

Not knocking the cheap 12v's themself which I have several in parallel for my 12v stuff but for the 48v stuff it just didn't add up cost wise for me.

Good luck with it though.

 

[portsample]

... as a 48v like I went with....

What brand did you go with?

 

[Crowz]

https://www.amazon.com/gp/product/B0B96ZDVW8/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

Showing $1279 right now. I got it for less by getting in on a lightning deal amazon has from time to time.

 

[50ShadesOfDirt]

I'm at 24v ... I have AmpereTime (now LiTime) 12v batteries in series for my simple battery-bank needs.

IIRC, they have both large AH batteries, and large BMS in/out amp boards (200amp or more), depending on the models you look at. Once you get above the 100ah models, the bms's are more powerful. More importantly, they'll tell you how many you can safely strap together to get to either 24v or 48v configurations.

Or, you can strap together their 24v models, which are in (slightly larger) standard 12v-like battery shells.

I currently have 4 x 12v300ah batteries, in 2s2p with busbars, for the battery bank.

I cannot recall where SOK is on this ... what models of 12v or 24v batteries they carry. Ask the folks at CurrentConnected. The only reason to prefer SOK over LiTime is SOK's wonderful repairability aspect. The LiTime's are sealed ABS shells, whereas the SOK's are typically metal, and nearly everything is field-replaceable.

Hope this helps ...

 

[portsample]

I'm at 24v ... I have AmpereTime (now LiTime) 12v batteries in series for my simple battery-bank needs.

IIRC, they have both large AH batteries, and large BMS in/out amp boards (200amp or more), depending on the models you look at. Once you get above the 100ah models, the bms's are more powerful. More importantly, they'll tell you how many you can safely strap together to get to either 24v or 48v configurations.

Or, you can strap together their 24v models, which are in (slightly larger) standard 12v-like battery shells.

I currently have 4 x 12v300ah batteries, in 2s2p with busbars, for the battery bank.

I cannot recall where SOK is on this ... what models of 12v or 24v batteries they carry. Ask the folks at CurrentConnected. The only reason to prefer SOK over LiTime is SOK's wonderful repairability aspect. The LiTime's are sealed ABS shells, whereas the SOK's are typically metal, and nearly everything is field-replaceable.

Hope this helps ...

Appreciate your detailed response. I pulled the trigger last night after Crowz post and picked up a 48v (51.2v?) 100A Chin battery on Amazon. According to Will Prowse, Chin batteries may be manufactured by AmpereTime as well, and appear to have at least good build quality. Best regards.

 

[Crowz]

You should be happy with that battery. I run my entire house on just one of those right now for backup in case of power failure. It last anywhere from 4 to 6 hours depending on what is running in my house at the time. Good battery.

I will be buying more of them.

 

[Vigo]

Im running 4x 12v 280ah in series with an 'equalizer' like Sunshine linked to. I haven't had any issues with the setup yet. In my case i chose that route because it worked out to ~14kwh for $2400 whereas in a server rack format i would get at most 10kwh for the same money. Plus if i decided it was unworkable they could be transitioned into 12v systems in my vehicles. That was my personal reasoning.

 

[portsample]

Im running 4x 12v 280ah in series with an 'equalizer' like Sunshine linked to. I haven't had any issues with the setup yet. In my case i chose that route because it worked out to ~14kwh for $2400 whereas in a server rack format i would get at most 10kwh for the same money. Plus if i decided it was unworkable they could be transitioned into 12v systems in my vehicles. That was my personal reasoning.

Appreciate your sharing your logic w/us. While I was attracted to the additional amperage provided by (4) 12v 200A in series, the simplicity of not having to deal with a controller (one more box) won out.

 

[sunshine_eggo]

Appreciate your sharing your logic w/us. While I was attracted to the additional amperage provided by (4) 12v 200A in series, the simplicity of not having to deal with a controller (one more box) won out.

Just to clarify, you don't get more current in series. If you have 4X 12V 200Ah batteries in series for 48V, and the batteries are rated at 200A discharge, you only get 200A discharge.

In parallel, amperage adds.

 

[portsample]

Just to clarify, you don't get more current in series. If you have 4X 12V 200Ah batteries in series for 48V, and the batteries are rated at 200A discharge, you only get 200A discharge.

In parallel, amperage adds.

Roger that. W/my new Chin I'll be at 51.2v 100A versus a series wired bank of (4) 12v 200A which would've put me at 48v 200A.