I'm attempting to use a BPL3650 36v Ryobi battery as the power source for replica electric willy's jeeps I've constructed for my kids.
- The batteries charge fine in the standard chargers available off the shelf
- The batteries work fine in the standard Ryobi 36v tools and respond as normal to the pressing of the battery stength indicator
However, when I go to use them in a circuit not in a Ryobi tool, they only appear to show 18.6v across the positive and negative terminals. I can exclude them from the circuit and just test the batteries with my multimeter and get 18.6v. Bizarrely, the actual behaviour the batteries exhibit is to start off at around 39v and over a period of about 10 seconds, drop to 18.6v (or approximately half voltage) as indicated by the multimeter. However, the batteries are actually fully charged.
There are 4 terminals on the battery, the middle 2 appear to be thermistors (designated T1 and T2)and when I opened the charger to have a look, only one of them was connected to the charging circuit board.
I'm 'assuming' that the battery must be getting some form of voltage across the second thermistor when in the actual hand tools that disables the battery protection circuits. Apart from dismantling a Ryobi 36v tool to see what might be triggering the circuit protection in the battery, I thought I'd post here to see if anyone has any thoughts or had already achieved this process themselves.
In short, does anyone know how to get the full 36v+ from a Ryobi battery outside a Ryobi powertool?
Update: Ended up dismantling a 36V strimmer to see what was going on. In the first picture below you've see the trigger switch (Jaiben DBW-2036E). The multimeter before the switch exhibits the same behaviour as before but after the swtich, a steady 41v. Would someone be able to tell me what the electrical component is that's connecting the two poles after the switch? All I can read on it is 10A so assuming amps of some form.