Page 1 of 1

Battery voltage limit < 43.01 not allowed / bad idea?

Posted: Wed Sep 04, 2019 11:45 am
by vobele
Hi,

I have a Xiaomi M365 Pro and would like to possibly prolong its battery live (I mean the life of the battery before going dead as such, not the capacity/range per charge). Li-Ion cells can live longer if they are not 100% charged. And I won't use the battery maximum capacity anyway in my daily use.

So I thought I would lower the settings at "Battery voltage limit" a bit lower than its default value which is 43.01

But both the Pro and the none-Pro firmware toolkits won't let you pach to lower settings. Only higher settings for battery upgrates are allowed.

Is it a bad idea to lower the Battery voltage limit value for the charging process to stop at 90% capacity? Or woult this prevent the BMS for balacing out the cell voltages at the end of charging?

Thanks

Re: Battery voltage limit < 43.01 not allowed / bad idea?

Posted: Sun Sep 08, 2019 6:44 pm
by vobele
Ok, think I found this out. The "Battery voltage limit" settings probably only are affecting the warning or cut off actions of the scooter during driving when for some reason the battery voltage is getting too high (i.e. excessive KERS recuperation downhill with fully loaded battery). The charging process - and when it shall stop - may be determined by the charger only. I found a video on Youtube called "Xiaomi mijia m365 charger hack" where a guy opened the original charger and showed where the voltage potentiometer is sitting. So I opened my charger too (yes I know, I did it on my own risk and never would animate others to follow this process without knowing exactly what they are doing..) and hence turned the output voltage down to 41.1 V. (Initially it was set at 41.7 which isn't that bad for battery life and security too, I have to admit)

So with the charger set to an output of 41.1V only, the charging process now stops somewhere around 94 to 97 % according the scooters display. In terms of cell voltage displayed in the M365 tools app, I see that they are never filled above 4.05 to 4.08 V. Whis seems fairly ok for my use.

But again: the initial setup of 41.7V of the original charger was better/lower than I thought. (In fact should not push the cells to their limit anyway)

Cheers

Re: Battery voltage limit < 43.01 not allowed / bad idea?

Posted: Thu Mar 26, 2020 11:10 am
by voryzen
Hi,

Could you post a link (or PM, whatever is allowed) to that video you are talking about?

I can't find it

Re: Battery voltage limit < 43.01 not allowed / bad idea?

Posted: Sat Jun 19, 2021 6:32 am
by Nicnyfiken
Xiaomi mijia m365 charger hack
https://youtu.be/U3H-BCXpAjU