bktrub@aol.com wrote:
> I've recently found that a 40 amp alternator is not sufficient to run a
> 13B  with electric fuel pumps and EFI. Seems the injectors take up a
> huge amount of amperage at higher rpms. I'm fine on the ground,- at
> about 13.7 volts, but when I'm running 5-6000 rpm, my voltage starts
> dropping and stabilizes at a little below 12 volts after an hour of
> flying. I have two 18 AH batteries. I"ve got a Dynon D10, terra 250
> Transponder, Xcom radio, EC2, EM2, and two fuel pumps from RWS. I only
> run one pump at a time except for takeoff and landing. Anyone know what
> the current draw for the injectors is at 6000 rpm?
>  
> Looks like I need to add another alternator.

Dang-it!!  Thank you for that report.  I've been running fine on the ground doing run-ups.  The biggest hit to the
batteries has been getting it started.  My electric load is probably higher than yours, since I'm also running an EWP.