There is not enough information to give a great reply.
I think I could disagree with a few statements... Devil's advocate kind of thing.
It goes back to what I sad about "Higher efficiency means more battery charging with less sweat."
Most ped-gens are horrible in the efficiency department.
Thats due to horribly inefficient PMAs. Tiny (cheap) PMA motors, etc.
Some cheap tiny PMAs actually make less power at higher RPM.
"1 hp" ECM.
It will be a LOT more efficient than most typical ped-gens, but doing an output wiring reconfiguration will make it more efficient.
"I can get 140 volts"
Yes, because it makes voltage in that configuration, but less amps.
For a 12V system it is not as efficient as it should be.
"I want to charge a 12 v battery or a portable power pack with an inverter"
That means the system has a little battery, which is SLA?
Really want to try to keep an SLA at no more than 13.8V, for a short time maybe 13.9V (IMHO).
"a portable power pack with an inverter"?
Most of those have tiny batteries.
Try not to charge the battery faster than about 20% of the capacity, or the battery voltage will get crazy, and the SLA will suffer an early death.
Combined, lets say you can pedal 50W for 30 minutes. That's over 3.6A, minimum.
The last couple portable battery do-hickies I had contained a 7AH-class SLA battery. 3.6A is >C/2.
That situation would be bad for the battery.
For example, a 7AH battery being charged with a 5W nominal solar panel, will go over-voltage in a short time.
It will not be fully charged. It will only be damaging itself from excessive voltage.
The 1 hp ECM is great for a ped-gen. Ask Norm!
The proposed battery is too small.
I would recommend reworking the ECMs wiring connections to IRP, and getting a bigger battery.
Might find something interesting here, but re-working a 1 HP for a ped-gen is less complicated,
http://s701.photobucket.com/albums/ww20/ghurd1/ECM%20Conversion/G-