using a battery powered motor to charge a battery

Yes it is possible to do this, but it would take more energy from the first (discharging) battery than you would add to the second (charging) battery. There are losses in the wires, in the motor and in the batteries than make the process less than 100% efficient. It might be more efficient to directly charge the second battery from the first, but there would still be losses that make it less than 100% efficient.

what if i use gears to make the secondary motor spin faster than the primary (discharging) motor?

i know there would still be a loss in energy via heat and friction but would that make the the transfer of power more efficient or at least compensate for the difference in energy?

what if i use gears to make the secondary motor spin faster than the primary (discharging) motor?

i know there would still be a loss in energy via heat and friction but would that make the the transfer of power more efficient or at least compensate for the difference in energy?

Good thought but unfortunately it doesn't improve efficiency. A gearbox can increase the output speed, but it correspondingly reduces the amount of torque so you can't get more total power out. And as you point out there are also more losses in the gearbox.

so what would the amount of energy loss be from my original idea?

would it be a 20% loss from heat and friction?

for car batteries roughly... you lose:

• 10% of discharging battery energy as heat
• less than 1% heating wires
• about 5% in the motor from friction and IR losses
• about 4% from friction in gears if you have some
• about 10% in the generator from friction and IR losses
• about 10% in charging the second battery as heat

nowhere do you gain energy in this system - the second battery stores some fraction of the energy (roughly 60%) supplied by the first battery

so for a 33v/51ahr lithium ion battery being charged id only be getting 19.8v?

The battery would likely charge very close to 33V, but the total charge might be closer to ~30ahr.  The voltage relationship to charge is not linear.  The battery rapidly rises to near it's terminal voltage, but charge (Ahr) is much more linear.