Charging the 7.2 Volt Batteries

[MikeDubreuil]

Originally Posted by Al Skierkiewicz

3. Many of you seem to be fully on board with a 12 volt charging circuit operated from the main battery. I am not, as it adds weight to your robot and steals power from the main battery. Simple buy two backup batteries and charge one while you use the other on the robot. If you find that you require higher current (due to multiple servos in your design) Digikey or other vendors can assemble battery packs in any current or package size you might desire.

I guess I'm on board with the idea for a couple reasons.

• I think adding the charging circuit will more fit the notion that the 7.2V battery is a true backup. I think it was a great mistake for IFI to power external devices through the 7.2V battery. I do like how the backup keeps the RC alive during brownouts. By adding the power charging circuit it makes the RC more the way I wished it was.
• I think the added weight will be negligible.
• The backup battery does not have to be easily accessible with a sturdier mounting system.

Either way you look at it there are engineering trade offs. I just feel the benefits of never having to manually charge the backup are worth the added weight.