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I guess you can put a relais/switch in for each cell in a series but then you need to account for voltage differences when taking them out. Either by over provisioning within the series and rotating in different cells. Or by have other strings take up the slack.

Either way you need some form of overbooking / compensating capacity.



A relay would allow you to switch it out and then back in again. Which you don't need. Just a fusible link that can be blown to permanently disconnect the battery from the string might be simpler and more ideal for the application.


Nearly all EV's today would run just fine on 3.7 volts fewer.

My car's high voltage circuitry seems to work down to about half of the nominal voltage.


Is the failure mode of whatever chemistry is in an EV that they just conduct electricity? Li-Po usually fail in more spectacular ways than so.


There's NCA (drones), NMC (laptops, phones, many electric cars), LFP (stationary/grid), and LFMP (many new electric cars; slightly more expensive but higher current variant of LFP).


Yes, this happens sometimes.

Search this page for "PTC": https://www.electricbike.com/inside-18650-cell/

The PTC protects the rest of the battery if a single cell internally fails short.




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