Hi, I have an el-cheapo Ryobi drill from Home Depot.
The battery pack has 4 contacts, (i.e. 4 blades), two seem to be GROUND, one measures 6 V and the other one 7.2 V. The pack itself is labeled as 7.2 V. The voltage between these two blades is 1.2V.
So it appears there is 6 batteries inside, in series, but there is one connector coming out between battery No 5 and No 6.
the charger itself has only 2 connecotrs, which couple with the GND and +7.2V on the battery. So during charging, the 6V blade is not connected.
The drill has 3 contact, one is GND, and the other two match the 6V and 7.2V on the battery. So it appears that the drill sucks power form both 6V (i.e. only from 5 NiCd cells) and also from 7.2 V (i.e. form all 6 NiCd cells).
Why is that? is that because the drill has 2 speeds? or is that because of the initial surge, it needs more current to start?
In either case, I am worried that some cells will get damaged by this uneven discharge circuit.
The battery pack has 4 contacts, (i.e. 4 blades), two seem to be GROUND, one measures 6 V and the other one 7.2 V. The pack itself is labeled as 7.2 V. The voltage between these two blades is 1.2V.
So it appears there is 6 batteries inside, in series, but there is one connector coming out between battery No 5 and No 6.
the charger itself has only 2 connecotrs, which couple with the GND and +7.2V on the battery. So during charging, the 6V blade is not connected.
The drill has 3 contact, one is GND, and the other two match the 6V and 7.2V on the battery. So it appears that the drill sucks power form both 6V (i.e. only from 5 NiCd cells) and also from 7.2 V (i.e. form all 6 NiCd cells).
Why is that? is that because the drill has 2 speeds? or is that because of the initial surge, it needs more current to start?
In either case, I am worried that some cells will get damaged by this uneven discharge circuit.
