I am converting a 36v drill to 18650
The problem I had was that my battery was producing around 42v and something in the connector area inside drill started smoking!
I considered a step down device from 42v to 36v but the appropriate size would not fit is the space I have available.
So I took out two cells thus giving me 4.2v x 9 = 37.8v, I tested the drill and smoke issue resolved.
However, this raises some questions...
Q1. how do I now wire my 10s BMS when I only have 9s now? Clearly it was expecting the following voltages
If I discard Wire 1 then wire 2 will not be happy with 4.2v as it was expecting 8.4.
But I can't disgard Wire 10 because it is wired internally in the BMS to the Main terminal B+
Q2. So do I just connect wire10 and wire9 to the last positive cell, that way the circuit in the BMS for wire 9 which would be expecting 33.3 to 37.8 would be happy and the circuit for wire 9 which would be expecting 37 to 42 would be happy, EXCEPT when the voltage on wire 10 falls below 37 which is only 0.8v.
Q3. Will having Wire 9 & 10 on the same contact cause any problem?
Q4. Is BMS only used in charging
Q5. Will it affect operation of the drill?
Q5. Will I still be able to use my 42v 3a charger, it does have a 36v on there but the rest is Chinese
I have uploaded image incase anyone can read Chinese!
It was ordered from ebay
https://www.ebay.co.uk/itm/383114371013
The problem I had was that my battery was producing around 42v and something in the connector area inside drill started smoking!
I considered a step down device from 42v to 36v but the appropriate size would not fit is the space I have available.
So I took out two cells thus giving me 4.2v x 9 = 37.8v, I tested the drill and smoke issue resolved.
However, this raises some questions...
Q1. how do I now wire my 10s BMS when I only have 9s now? Clearly it was expecting the following voltages
If I discard Wire 1 then wire 2 will not be happy with 4.2v as it was expecting 8.4.
But I can't disgard Wire 10 because it is wired internally in the BMS to the Main terminal B+
Q2. So do I just connect wire10 and wire9 to the last positive cell, that way the circuit in the BMS for wire 9 which would be expecting 33.3 to 37.8 would be happy and the circuit for wire 9 which would be expecting 37 to 42 would be happy, EXCEPT when the voltage on wire 10 falls below 37 which is only 0.8v.
Q3. Will having Wire 9 & 10 on the same contact cause any problem?
Q4. Is BMS only used in charging
Q5. Will it affect operation of the drill?
Q5. Will I still be able to use my 42v 3a charger, it does have a 36v on there but the rest is Chinese
I have uploaded image incase anyone can read Chinese!
It was ordered from ebay
https://www.ebay.co.uk/itm/383114371013