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Bate Lithium potentially misleading Low Temp Cutoff

rafasfdc

New Member
Joined
Nov 13, 2022
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I just purchased 2 Bate Lithium 100Ah USB boxes. Advertised on Amazon as enabled for Low Temperature Cutoff.
Very nice packaging. They look Milspec. The metal box almost looks like an ammo box. It has 2 heavy duty handles.
Much heavier than expected. They also installed a small Supnova voltage/temperature monitor. Not great, but better than nothing!

In any case, I contacted the vendor to inquire about the BMS parameters. Though very responsive, the vendor's answer was...
underwhelming...

Question:

What are the BMS temperature range settings?
At how many degrees F will it cut off in cold and hot conditions ?
And how do you reset the BMS ?"
Vendor Reply:
"

1. The temperature range of BMS is -20~75℃, (-4F~167F)
2. less than -4F or higher 174F the BMS will cut off
3. It will be reset the BMS once it cut off autotally.
4. The working temperature range of 12V100A lifepo4 battery is -5~75℃, (23F-167F)
"

Follow Up Question:
If the lowest working temperature for your battery is -5℃, why would the bms on the 12vusb100ah be set to cut off at -20℃ ? A destroyed battery is allowed.
Vendor Reply:
"
Nor is it permissible to damage the battery.
Because battery manufacturing materials are generally divided into special materials or conventional materials. When the battery is made of special materials, the minimum working temperature can reach -20℃, which is the same as BMS.
When the battery is made of conventional materials and cannot reach BMS-20℃, the battery will be cut off when it reaches the minimum operating temperature of the battery -5℃. It will work again when the temperature returns."
"

Final Followup
Does this mean I can allow my Solar Panel controller charge the battery at any ambient temperature, even below 0 ? Will your BMS ensure the
battery will not be damaged ? Even above 20 Amps input at - 4℃ ?
Vendor Reply:

"You can let the solar panel controller charge the battery, but it is recommended to be above 5°C. Because below 0 ℃ can not be completely sure whether it can charge or discharge, even if it can charge may be a very small current, this time charged in the battery panel may not show a charge. But you can test whether the battery can be discharged when it is below 0℃, if it can be discharged, then it can be charged. Battery charging current between 2-100AH is possible. In addition, if the ambient temperature changes a lot, you can also add a heater to the battery."

Conclusion
To my understanding, this BMS is utterly useless. And its false advertising from the vendor.
Though I love the packaging, I am leaning on returning the batteries.

(see pic; left the battery outside as low as -2℃, as expected, did not cutoff )
BateL.jpg

Thoughts?
 

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Last edited:
The vendor wrote back.
"Thank you for your suggestion regarding the description of the low temperature cutoff. We will make changes to the product details on Amazon"

The BMS will only protect against battery discharge under extremely low temperature.
 
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