Hey,
i just built my first 18650 Pack. 7s4p.
I installed my self-soldered diybms and everythings seems to work nicely.
Then i connected one of these diy PSU Riden® dps5005 50v 5a buck adjustable dc constant voltage power supply module integrated voltmeter ammeter with color display Sale - Banggood.com
to my battery and switched it on.
on three modules the blue LED blinked and the green ones stopped to “wander” along.
I switched it off and on once more and now 1 of my diyBMS Modules doesnt measure voltage anymore and tells -40°C as temperature.
Could it be destroyed by backfeed voltage from the psu? How can i find out?
OK,
i found out what the problem is, but not how it happened:
when i looked at the faulty module configuraion i saw that values have been “erased”.
The screenshots show the faulty module 6 and the working module 5.
I was able to update the values manually and now its working again.
How did that happen?
This is what happens when i switch on the PSU thats attached to the Battery.
Sometimes, after that the WebGui tells me the connection to the modules is lost (The green lights still make the “lightshow”)
The only solution here is to deconnect them from the battery and reconnect them.
I was not able to measure any voltage peaks on connect/switch on of the PSU but maybe my multimeter is too slow?