Help! Battery 36v lithium

[Stevo55]

Please could someone explain this to me in simple language. My new battery pack is fully charged and showing 40v ish. If I leave overnight it shows about 2v and won’t take any more charge through the charging port.
if I reverse charge through the main power feed after 10mins it’s showing full power again. I’ve done this a couple of times now obvs making sure nothing gets warm and it happens just the same way ‍
Wat could be the cause of this and what am I doing sort it out ?

 

[guerney]

Hey , ye seems to be working great. All good so far

Did you replace your BMS with an Ann Power?

 

[Nealh]

Ann power BMS I found have always been good better still if one gets one with a switch, sadly though they don't (or didn't) when I wanted one make a smaller 12s one . One reason why I tried the acronimic BeMuchSafer brand.

 

[guerney]

Ann power BMS I found have always been good better still if one gets one with a switch, sadly though they don't (or didn't) when I wanted one make a smaller 12s one . One reason why I tried the acronimic BeMuchSafer brand.

Good point about the switch - it's weird that on the ANNPower store...

https://annpower.aliexpress.com/store/623665

...there are no 36V 10S BMSs above 20A which have anything other than a temperature switch, but a switch can be fudged using the temperature switch wires, as shown by "The Battery Doctor" on the 40A. Maybe Sur-ron owners never need to switch their bikes off, because of constant need for speed or something.

20A BMS with switch:

9.26￡ 33% OFF|36v Li-ion Battery Bms, 10s 36v 20a Lithium Ion Batteries Bms, With Balanced Function And On/off Switch. - Battery Packs - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

40A BMS without switch:

14.13￡ 10% OFF|10s 36v Li-ion Battery Protection Board,for 36v 40a Lithium Ion Battery Pack With Balance Function - Battery Accessories & Charger Accessories - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

 

[saneagle]

Good point about the switch - it's weird that on the ANNPower store...

https://annpower.aliexpress.com/store/623665

...there are no 36V 10S BMSs above 20A which have anything other than a temperature switch, but a switch can be fudged using the temperature switch wires, as shown by "The Battery Doctor" on the 40A. Maybe Sur-ron owners never need to switch their bikes off or something.

20A BMS with switch:

9.26￡ 33% OFF|36v Li-ion Battery Bms, 10s 36v 20a Lithium Ion Batteries Bms, With Balanced Function And On/off Switch. - Battery Packs - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

40A BMS without switch:

14.13￡ 10% OFF|10s 36v Li-ion Battery Protection Board,for 36v 40a Lithium Ion Battery Pack With Balance Function - Battery Accessories & Charger Accessories - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

You can put your own switch on wherever you want. You can put it on any of the sense wires, which makes a good test that the BMS is actually working too.