Use of LiFePO4 cells?

[yubyub]

I am replacing a prior motor controller with a new Roboclaw.

Right now, the batteries are a set of 2 series cells of LiFePO4, which give a nominal 6.4VDC output. I see that the Roboclaw suggests 6VDC as a minimum input - and I am worried about having enough overhead in the current batteries to successfully drive the Roboclaw (i.e. transient dips in the voltage, etc).

Does anyone have experience with this? Will 6.4VDC work, or would it be wiser to change the cells to a different chemistry and go for 7+VDC? The motors I am controlling won't mind the extra bit o' voltage, but I do try to keep the batteries safe (for both the user and the environment), and was hoping to stay on LiFePO4s if possible.

Thanks,

[Basicmicro Support]

If 6.4v will be a problem depends on the load and how much voltage drop you will end up getting when driving the load. In general the LifePO4 cells will be around 3.2v during 90%+ of their discharge cycle. Make sure the current rating of the batteries is enough for your application and the voltage drop under load shouldnt be a problem.

Note that as long as the logic voltage doesnt drop lower than 5.5v the controller will not error. It will instead freewheel the motors when the main battery voltage drops below 6v and drive the motors again once it has come back up(eg under a particullary heavy load you may see this happening).

[yubyub]

Very cool, sounds like it's worth a try. I'll try to post back with any issues (or success).

Thanks!

[Basicmicro Support]

Yes, please let us know the results. Thanks.