Dyson V7 not working. Is it motor or battery?

[hw_user]

My Dyson V7 stopped working. I want to know if it is my battery or the motor is bad.  I did two tests
1. I pulled out the battery. I can see the trigger button and the + and - slots where the two tongues from the motor side inserted into. I inserted a piece of wire into each slot and meter the voltage. There is no output with or without the button pushed. The vacuum is plugged in all the time. I think the battery is at least somewhat charged. I should see some voltage. Do I have to insert a piece of metal similar to the tongue to see the output?
2. I use a DC power supply to provide 21 volt (I think the battery is 21.6V) directly to the two tongues. But the motor is not turning. I think the trigger is on the battery side. Unless there is any hidden switch, the motor should turn.
Can anyone help?

[darkspr1te]

this link might help, they talk about magnets in the body and battery to detect each other.

https://www.eevblog.com/forum/reviews/dyson-v7-trigger-cordless-vacuum-teardown-of-battery-pack/

darkspr1te

[macboy]

I powered a V6 directly, but you need a very high current supply to do this. The motor can pull tens of amps when starting.

So you get any blinking if the LED on the battery? Different number of flashes indicate different errors. A common issue with these batteries is the cells become unbalanced over time since the BMS does no balancing. When it gets bad enough, the battery terminates itself and will never work again. The only fix is to install a third party firmware in the battery to unlock it. You also need to balance the cells of course. The are threads in this forum about these batteries and the replacement firmware.