I believe so.
Finally found a LiFePO4 BMS with Low-temp Charging Protection
- Thread starter Will Prowse
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OverkillSolar
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this might be it- no promises: https://www.aliexpress.com/item/32974794884.html?spm=a2g0o.detail.1000023.14.5ff563deKCelO5
Sgt Raven
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I need to figure out how to save my current use data, before changing.
kitling89
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Hi, new to the forum here but have some limited experience with building batteries. I have some used 12v LiFePO4 with useless BMS that I want to upgrade.
If I got this BMS 12S can I wire the 3 packs in parallel and have it monitor all 12 cells? Or do I have to have a seperate BMS for each set of series cells.
I would like to preserve the packaging and not tear them apart a rewire them individually in parallel. Basically just wire the BMS into the end of the parallel string and each balancing lead to the individual cells.
If I got this BMS 12S can I wire the 3 packs in parallel and have it monitor all 12 cells? Or do I have to have a seperate BMS for each set of series cells.
I would like to preserve the packaging and not tear them apart a rewire them individually in parallel. Basically just wire the BMS into the end of the parallel string and each balancing lead to the individual cells.
OverkillSolar
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Can you post a picture of the cell pack that you're working with?
Great thread! I am very much interested in the 8S version.
Does anyone know which mosfet is used in the 100A 8S version? By the photos it seems to be a TO-263. It cannot be the same of the 4S version, as the (good) mosfet used is only rated to 30V Vds.
I want to antecipate how well can the 8S widthstand continuous high currents, in the order of 90~120A. Maybe adding passive cooling, but need to know the Rds of the mosfet used.
Does anyone know which mosfet is used in the 100A 8S version? By the photos it seems to be a TO-263. It cannot be the same of the 4S version, as the (good) mosfet used is only rated to 30V Vds.
I want to antecipate how well can the 8S widthstand continuous high currents, in the order of 90~120A. Maybe adding passive cooling, but need to know the Rds of the mosfet used.
OverkillSolar
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I sent the only 2 samples I had of that unit to a customer to try and it didn't go well. (the magic smoke came out)
So until we determine why or how that happened I'm not going to order any more.
Sgt Raven
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I hate when that happens. Even more when I bought something new, set it on a shelf for 2 years without testing it.
Then the Magic Smoke came out, when I did, and I was shit out of luck for getting it replaced.
@OverkillSolar : do you know at which parameters did your customer manage to disrupt the BMS?
I was looking today at affordable Mosfet alternatives to work over 30V (30V is not ok to use at 24V banks) and I couldn't find very much altenatives. IRFB7730 is one of my favourites, but Rds is still higher than HY4903.
So... I wonder which one is being used in 8S. That will gives a fairly good indication on the robustness of the 8S version.
I was looking today at affordable Mosfet alternatives to work over 30V (30V is not ok to use at 24V banks) and I couldn't find very much altenatives. IRFB7730 is one of my favourites, but Rds is still higher than HY4903.
So... I wonder which one is being used in 8S. That will gives a fairly good indication on the robustness of the 8S version.
OverkillSolar
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It was something done out of sequence during the installation. We dont know for sure yet.
Somewhere, that I cant find now, I wrote down the mosfet part numbers that you are after. IIRC they were rated 80v in the 8 cell BMS.
nvm I found it, they are TTB145N08A
TO-263 package, Drain current 145A each, Vdss 82v, Rds 4.8 milliohm
ok, so the IRFB7730 is a better alternative. I'm considering the idea of swapping the SMD mosfets to lower the dissipated power with high currents. Has anyone tried this?
BTW - does anyone know which transistor is involved in the balancing part that sometimes gets fried? Maybe a normal "547" or similar?
Lithiummen
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Is it possible to lock settings? To avoid customer messing with settings?
Sharky722
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485 is a communication standard that is used to communicate between bms and user via cable and a pc. It may let you change more parameters etc than bluetooth.
Sharky722
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I don't know sorry I'm out of my depth here lol.
I just know it a comms standard.
I’ve never seen a 484 unit personally. The one I sell has a UART port, which is compatible with the Bluetooth modules and USB modules.
The commands available would be the same as far as I know.
OverkillSolar
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Somehow I got logged into a different account lol
backforty2
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Some one pointed out to me, Winston seems to claim charging to -45C. I assume this is a miss print? http://www.evlithium.com/thunder-sky-winston-battery/lifepo4-100ah-b.htmlSpent the last few days and tonight testing BMS:
1. The "new" daly LiFePO4 BMS (that states in the data sheet that it has low temp charging protection) does not have low temp charging protection. And yes, it has a temp sensor attached. This disappointed me big time. Video to come.
2. Next, I programmed/tested this BMS for a couple of days:
View attachment 4222
And it failed. App would crash. Default low temp cut off was -5 degrees C. No manual and very difficult to work with. Had a lot of issues with it. Will cover every downside in my upcoming video. Avoid this BMS.
3. Then I tested the battery hook up 100A BMS that arrived this afternoon:
View attachment 4223
And low temp cut off was programmable and worked perfectly. Bluetooth connected perfectly as well. I was excited so I did a load test of 200Wh with 90-102A continious. Passed with flying colors, then pushed it passed its limit and it disconnected the loads. Heatsink stayed warm and did not heat up excessively.
I'll make a long video covering all these things and the testing methods, but I am going to go with this bms from now on. I am so tired of other bms failing. The battery hookup one is used on medical devices as well, which I need more information on.
The number one most important thing to know when using this bms is that you need the proper app. The app on the website is NOT what you want. You need the "enterprise" version:
Click Here for APK of enterprise BMS program app
Send it to your phone with an email (not gmail), then install in on your phone, then connect to bms.
Then go to parameter settings and change the low temp charging cut off to 2 degrees Celsius. Then the reconnect voltage to 5 degrees Celsius.
You can buy this bms by clicking here (my affiliate link) and the coupon code is "SOLAR" for 10% off. I am going to get a 8s model and build a big system with it. I like this bms a lot, so will be testing it like crazy. I also will make a DIY video on how to use it in the next couple days (possibly tomorrow if I get enough sleep tonight).
Biggest downside of this bms is 2x 10 gauge wires at P- and B-. But it has a hole and solder tabs for adding more wires.
Just wanted you guys to know about all this before you waste your money on the first 2 bms. I wasted $150 on those bms and they were a total rip off. The new bms seems to kick butt, so videos to come.
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