Batteries — TonyBot Service

Each bar is one cell, filled to how much charge it holds. Cells sit in a chain, so a pack is only as good as its weakest one. Full is 12.6 V across the three. Click a robot to see its full reading.

Reference

What each robot runs on

Robot	Pack	Full	Charge it at	Charger
#1, #3, #4TonyBot	3S lithium, 11.1 V nominal 2000 mAh, 10C	12.6 V	Under 11 V	12.6 V 2 A
#2SpiderPi	3S lithium-ion, 11.1 V nominal 2500 mAh, about 40 min	12.6 V	Under 10 V	12.6 V 2 A DC 5.5 × 2.5 barrel
#6PuppyPi	2S, 7.4 V nominal, cylindrical cells 2200 mAh, labelled Li-polymer	8.4 V	Under 6.8 V	8.4 V round socket on the Pi board
#5AiHand	No battery mains only	7.4 V	Not applicable	7.4 V 3 A adapter

Never swap these two chargers

The 12.6 V charger and the 8.4 V charger both end in a barrel plug and both fit. Putting the 12.6 V charger on Robot #6 pushes two cells to 6.3 V each, well past the 4.2 V a lithium cell takes. That is a fire, not an empty battery. Robot #6 is the only 2 cell pack in the batch, so it is the one to keep apart from the rest.

Robot #2 and Robot #6 have not been opened yet, so those two rows are the published figures rather than anything measured here. Robot #6's pack has since been opened and its row is what was found here, not what was published. Robot #2 is the Advanced Kit, so the 2500 mAh figure applies. The Pro carries a larger 3500 mAh pack.

What this means

In short

Two batteries have failed and need rebuilding, on Robot #1 and Robot #4. A battery is a wear part.
The faults you reported were power. Robot #4 lost power mid-step and fell over. Robot #1 stopped during a push-up. Both test sound on a good battery.
Robot #3's battery still works. One of its three cells is weaker than the other two.
The charger is fine. It does not need replacing.
Three batteries are still to open and measure. Every pack gets checked cell by cell, so you get one exact count of what to replace.

Batteries age whether you use them or not. A set bought at the same time tends to fail at the same time.