BYD 24V LiFePo4 Battery Modules

[ytwytw]

I am buying three of the BYD 24V battery modules, picking them up next week from batteryhookup store.

According to the specs, it works with standard 24V systems (I have a MPP Solar 24V Hybrid Charger Inverter so sounds perfect to me)

NOMINAL VOLTAGE IS 25.6V
FULLY CHARGED IS 29.2V
FULLY DISCHARGED IS 20V
CONTINUOUS CHARGING 2500W
CONTINUOUS DISCHARGE 5000W

$450 for approximate 4-4.5kWh is a ridiculous price, the cell seems by BYD as well

Any recommendation for the 8S BMS?
I am in upper state NY and I need low-temp cut off + low voltage cut off feature for sure.
Is there anything else I need to consider to use the battery in cold region?
I am replacing those GC2 battery and they are in my shed.

 

[MV EVERLONG]

Thanks for posting this. I just ran across those myself. I was thinking of getting 8 of them and trying to figure out how to integrate them into my boat's system. No solar yet but 27kw generator running a little 12v, mostly 110v and 220v systems. I really want to use these as a house bank which I don't really have.

 

[KBWaldron]

I am buying three of the BYD 24V battery modules, picking them up next week from batteryhookup store.

According to the specs, it works with standard 24V systems (I have a MPP Solar 24V Hybrid Charger Inverter so sounds perfect to me)

NOMINAL VOLTAGE IS 25.6V
FULLY CHARGED IS 29.2V
FULLY DISCHARGED IS 20V
CONTINUOUS CHARGING 2500W
CONTINUOUS DISCHARGE 5000W

$450 for approximate 4-4.5kWh is a ridiculous price, the cell seems by BYD as well

Any recommendation for the 8S BMS?
I am in upper state NY and I need low-temp cut off + low voltage cut off feature for sure.
Is there anything else I need to consider to use the battery in cold region?
I am replacing those GC2 battery and they are in my shed.

In another thread @Will Prowse had recommended the Daly commmon port 24v, 8s, 200amp BMS, which aligns with the discharge profile above.

 

[KBWaldron]

@Will Prowse - In addition to the discussion above here's a quick question. I bought two of these BYD batteries and now am going to add the Daly BMS you recommend. Instead of buying two BMS can I instead connect each corresponding cell in parallel to between the batteries (i.e. 8 sets of cells in parallel, then connect each battery in parallel. That will keep each pair balanced and provide 24V and 400 amp capacity. Then I use one BMS to keep the 8 cell pairs balanced.
The only issue then is that I have a maximum current requirement of 400 amps, for which I can't find an equivalent BMS.
You mentioned using an external relay in such situations, but I'm unclear as to how that would work. Can you elaborate?

Oh, and by the way, do you have a Patreon account? You are saving me so much time and money I feel I need to repay you.

 

[ytwytw]

@Will Prowse - In addition to the discussion above here's a quick question. I bought two of these BYD batteries and now am going to add the Daly BMS you recommend. Instead of buying two BMS can I instead connect each corresponding cell in parallel to between the batteries (i.e. 8 sets of cells in parallel, then connect each battery in parallel. That will keep each pair balanced and provide 24V and 400 amp capacity. Then I use one BMS to keep the 8 cell pairs balanced.
The only issue then is that I have a maximum current requirement of 400 amps, for which I can't find an equivalent BMS.
You mentioned using an external relay in such situations, but I'm unclear as to how that would work. Can you elaborate?

Oh, and by the way, do you have a Patreon account? You are saving me so much time and money I feel I need to repay you.

Try this bms

9.85US $ 23% OFF|Smart 7s ~ 20s Ant Lifepo4 Li-ion Lipo Lto Battery Protection Board Bms 400a 300a 80a 500a Bluetooth App 10s 13s 14s 16s Balance - Battery Accessories & Charger Accessories - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

you need to solder your own wire on it, the wire come with it is only 10/12AWG, not gonna work for 400Amp

 

[Picasso]

The BYD's I got do not have the same BMS inside them as the one in David Poz video. It is missing the bigger board that his have. Also I found some dates. Some of the plastic has marks from 2016 and some parts also 2014. Looks like the BMS boards got changed after mfg newer date vs the other plastic molds. The bms in my unit is talking CAN/rs485 but havnt attempted to decode.\

One of the fans in the units I got had chewed up the balance wires.

 

[ytwytw]

The BYD's I got do not have the same BMS inside them as the one in David Poz video. It is missing the bigger board that his have. Also I found some dates. Some of the plastic has marks from 2016 and some parts also 2014. Looks like the BMS boards got changed after mfg newer date vs the other plastic molds. The bms in my unit is talking CAN/rs485 but havnt attempted to decode.\

One of the fans in the units I got had chewed up the balance wires.
View attachment 2561View attachment 2560

Can you help to the a pic of the full warranty sticker and the label of the battery package?
Trying to see if I can find some info or software from alibaba

 

[KBWaldron]

David Poz just posted his solution to providing terminals for these batteries.

I had to laugh as I had the same approach in mind last night and was checking out pipe dimensions to pick a starting point. I have a mini-lathe, and so I may increase the internal diameter a couple thousands. As it is right now the pipe internal diameter he used is 6/1000" smaller than the existing terminal. I'd like to drop that to 2/1000", but we'll see whether I bother to take the time to set up the lathe.
Copper is pretty ductile so driving the pipe on likely will just stretch the pipe.

 

[JRP3]

Anyone find a connector that matches the 32 pin 2mm pitch plug which goes into the BMS board? I'd like to make a plug which uses the existing wires and connector but haven't found an exact match, it doesn't seem to be a Molex part. This looks to have the right pin count and spacing but I'd probably have to cut some of the plastic off the housing to mate with the plug on the pack
https://www.digikey.com/product-detail/en/molex/0559173210/WM12280-ND/3263376

 

[JRP3]

Forgot to include a pic of the plug on the pack

 

[batteryclearinghouse]

Please be careful about trying to use the built in wires for anything other than monitoring. There is section that's thin traces on a green board. I am not 100% convinced they will handle the amps being pushed out by the various BMS units during balancing when your cycling them.

Keep in mind that these units where part of large battery banks. The design might have only required a trickle of power for balancing based on that unique type of usage pattern.

Just a random thought to consider...

 

[maxx123]

Please be careful about trying to use the built-in wires for anything other than monitoring. There is a section that's thin traces on a green board. I am not 100% convinced they will handle the amps being pushed out by the various BMS units during balancing when your cycling them.

Keep in mind that these units were part of large battery banks. The design might have only required a trickle of power for balancing based on that unique type of usage pattern.

Just a random thought to consider...

I agree, I pulled the monitoring boards out, drilled out the rivets, re riveted in a proper bms lines all the same length, mounting the bms where byd board was, near the fan to keep cool.
Also got rid of the two front posts

 

[maxx123]

Please be careful about trying to use the built in wires for anything other than monitoring. There is section that's thin traces on a green board. I am not 100% convinced they will handle the amps being pushed out by the various BMS units during balancing when your cycling them.

Keep in mind that these units where part of large battery banks. The design might have only required a trickle of power for balancing based on that unique type of usage pattern.

Just a random thought to consider...

I found burnt traces on my board

 

[JRP3]

For now I just wanted to use it for monitoring without running new wires. For attaching new wires I found that the existing holes in the cell buss bars will take a #8 - 32 self tapping screw. Does anyone know why the black wires running to the existing BMS plug don't seem to connect to negative? I only get cell voltages from the plug if I use the main negative terminal.

 

[maxx123]

heat sensor

 

[ytwytw]

I think those are temperature sensor, but without enough info, I guess we could not utilize it for anything

 

[Picasso]

The build differs sightly vs what I got from https://www.techdirectclub.com/ vs https://batteryhookup.com/

Heatsinks not black, clear covers on lugs, stickers removed, random writing. inspecting more and will capacity check vs my other 4.

 

[jasonhc73]

The BMS balances at 1/5 of an amp, or 200 MA.

24AWG wire is capable of 3.5 amps just fine.

BYD BMS

A no cut, no splice, plug-n-play. It has a screen, Bluetooth, and more settings in the app than we know what to do with. Will already reviewed this BMS. The Inside wires: The Outside Wires: Conclusion: Molex Micro-Fit 3.0 430251000 10POS 3mm Molex Micro-Fit 3.0 or 1729521001...

diysolarforum.com

 

[Picasso]

Some of the BYD packs have different cell manufacturing types. left cells from 2014-early15 right 2016 cell and data stamps on plastics. Also note PCB sensor board change. This pack came with a pure passiv bms on it. just reading data.]]


Edit: this newer pack the voltage temp/senor differs vs the others. I get a few mv lower when reading from the + side of these via the PCB. PLEASE tell people to wire direct to the cells, I dont get this sensor thing at all if it needs to be back powered, it has + and - being sent via that master control chip on the default BYD BMS sorry I just fear it cause Ive never seen this type of voltage / temp senor. I'd like to learn more about it and the chip in the byd bms talking to them and reporting back out CAN.

 

[Darkstar]

Some of the BYD packs have different cell manufacturing types. left cells from 2014-early15 right 2016 cell and data stamps on plastics. Also note PCB sensor board change. This pack came with a pure passiv bms on it. just reading data.]]


Edit: this newer pack the voltage temp/senor differs vs the others. I get a few mv lower when reading from the + side of these via the PCB. PLEASE tell people to wire direct to the cells, I dont get this sensor thing at all if it needs to be back powered, it has + and - being sent via that master control chip on the default BYD BMS sorry I just fear it cause Ive never seen this type of voltage / temp senor. I'd like to learn more about it and the chip in the byd bms talking to them and reporting back out CAN.

Did both of those packs come from the same company on the same order?