Hello,
I just got a 3.7v 3000mah battery with JST-ph connector for my mbot. Wondering a few things:
1/ How long I should expect it to charge through the USB
2/ Should expect less speed from the motors than when I use the 6v Battery Pack?
Thank you
Rob
Hi Rob-
Charge time, I think, is dependent on the amperage of the USB port. You can read about the basics of LiPo/LiON charging on this adafruit page. https://learn.adafruit.com/li-ion-and-lipoly-batteries/proper-charging. We use 7800mah LiON batteries with 1A ports of powered USB hubs for our fleet of mBot and mCore, and charge time is in the “few hours” range. Battery life with a single motor spinning from an uploaded Arduino program was about 2.5 days.
On the mCore, all power runs through a 5v regulator. Although there are “separate” power lines that run into the H-bridge, they’re from the same post-regulator circuit.
This blog post has a good look at the mCore schematic.
It’s possible that I’m misreading the power flow from the schematic itself! If anyone has a ton of experience in this and thinks I’m off-base, please let me know.
–andrew