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Finally found a LiFePO4 BMS with Low-temp Charging Protection

Rare earth yttrium battery...

Huh?
Winston aka Thundersky adds yrrtrium to their LiFePO4 batteries. Technically theylre LiFeYPO4 batteries. Studies have found it improves performance in all sorts of ways.

I'm not sure anyone besides Winston does this. It might be part of the reason Winston batteries are so expensive and so popular. Originally I was going to use them, but the size & weight compromise vs. "blue aluminum" cells was just too much for my portable application.
 
So that is not some misprint on the temps, they really can charge down to that low of temp? If that's the case, I am REALLY happy both of my DIY packs are using these. I guess I can set a lower charge temp value in the BMS.
 
So that is not some misprint on the temps, they really can charge down to that low of temp?
I'm not saying that. :p I don't know.

What I found:
"the small amount of Y3+ ion-doped can keep the microstructure of LiFePO4, modify the particle morphology, decrease charge transfer resistance, and enhance exchange current density, thus enhance the electrochemical performance of the LiFePO4/C."

It seems to be related to the performance/longevity of the cathodes. Someone else somewhere also mentioned temperature.

If you're really interested:

 
Spent 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. :)
It is very frustrating to see a recommendation to a product that is not available.
 
It is very frustrating to see a recommendation to a product that is not available.

Is this the link you are referring to:
The product you are referencing?

If so, I'm pretty certain the same model is available from other sellers (Overkill Solar who is a forum member here sells it, as do various other sellers on Aliexpress and elsewhere)
 
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GOOD NEWS: Overkillsolar.com has it in stock :cool:

Overkill, do you carry -or- do you plan to carry -or- could you please carry...this version: https://fr.aliexpress.com/item/4000776885236.html


Pics and quote from another thread:

The BMS is compact and feels very robust, encased in metal all the way. Proper copper leads, two external temperature sensors. It supports low and high temp cut-off. Of course, 'manual' is lacking, so just for reference: it won't turn on until you put a charger on it (voltage applied needs to be higher than the battery voltage), the Bluetooth pairing code is '1234' and the pin code to make changes to the BMS values is '123456'.
DSC_1348-preview3.jpg



Screenshot of the app. I just put a quick 16 cell pack together, so ignore things like wire resistances and remaining capacity etc. The voltages are looking good, and the integrated balancing seems to work very well. This is the 100A discharge current with 0.6A balancing current version I got to test and play with. If this thing works properly, I'll get the one with 300A discharge current with 2A balancing current version.
Screenshot_2020-06-10-14-48-36.png
 
Overkill, do you carry -or- do you plan to carry -or- could you please carry...this version: https://fr.aliexpress.com/item/4000776885236.html


Pics and quote from another thread:

The BMS is compact and feels very robust, encased in metal all the way. Proper copper leads, two external temperature sensors. It supports low and high temp cut-off. Of course, 'manual' is lacking, so just for reference: it won't turn on until you put a charger on it (voltage applied needs to be higher than the battery voltage), the Bluetooth pairing code is '1234' and the pin code to make changes to the BMS values is '123456'.
DSC_1348-preview3.jpg



Screenshot of the app. I just put a quick 16 cell pack together, so ignore things like wire resistances and remaining capacity etc. The voltages are looking good, and the integrated balancing seems to work very well. This is the 100A discharge current with 0.6A balancing current version I got to test and play with. If this thing works properly, I'll get the one with 300A discharge current with 2A balancing current version.
Screenshot_2020-06-10-14-48-36.png
I sent out a request for wholesale pricing. Do you know if it has low temp cutoff?
 
I sent out a request for wholesale pricing. Do you know if it has low temp cutoff?

Apparently, yes it does...

"Proper copper leads, two external temperature sensors. It supports low and high temp cut-off."
Quote is from user: upnorthandpersonal who is currently using this BMS
 
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Apparently, yes it does...

"Proper copper leads, two external temperature sensors. It supports low and high temp cut-off."
Quote is from user: upnorthandpersonal who is currently using this BMS
I'm going to look into it. Their janky website doesn't have the 16s model but it does have a pretty cheap 4s 300a unit that looks really interesting.
 
I'm going to look into it. Their janky website doesn't have the 16s model but it does have a pretty cheap 4s 300a unit that looks really interesting.
janky website for sure...but I believe I'm seeing units ranging from 14s to 24s, no? The one upnorthandpersonal (pictured in post #969 above) is currently using is 16s and he says it came from that site.
 
Any news on a 8s version? :unsure:
In fact there is news. I got 30 of them in and tested one while making a video assembly guide. It works fine, just like the 4s unit.

I will put them up for sale soon. Trying to edit the assembly vid to make me look less of a goober.
 
In fact there is news. I got 30 of them in and tested one while making a video assembly guide. It works fine, just like the 4s unit.

I will put them up for sale soon. Trying to edit the assembly vid to make me look less of a goober.

? That is news! How many amps are they rated at?
 
janky website for sure...but I believe I'm seeing units ranging from 14s to 24s, no? The one upnorthandpersonal (pictured in post #969 above) is currently using is 16s and he says it came from that site.

Who manufactures this BMS? Could you post a link to the website you are referring to, all I see is the aliexpress link above.
 
Who manufactures this BMS? Could you post a link to the website you are referring to, all I see is the aliexpress link above.
The forum user who has this BMS (upnorthandpersonal) only provided that aliexpress link. Not sure who manufactures it...possibly:
Heltec.JPG

BTW, he did confirm the low temp cutoff works as advertised.
 
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