I have a pair of 775 12V dc motors. I want to use them with a pair of BTS7960 motor drivers with Arduino. According to the datasheet, the stall current is 20 Amps for 1 motor. If I have a 12V 50Ah battery, theoretically it can provide enough Amps for 1 hour even on stall current, right?
I want to drive the same shaft with the 2 motors if it matters.
Question 2:
Is the current draw dividing between the 2 motors under the same load?
(An example for better understanding: If 1 motor would draw 10 Amps, then under the same load, the 2 motors would draw 5-5 Amps? Or 10-10?)
Is the battery a LiPo? If so what is the C rating of the battery?
The C rating is the cells maximum safe discharge rate of LiPo's. Take the C rating and multiply by the Amp rating.
For example, using a 5000mAh 20C 7.4V (2S) LiPo. Convert the mAh to amps. There are 1000mAh in 1amp so, in this case, the 5000mAh pack is equal to 5amps. Now, simply multiply the capacity in amp hours by the packs C rating (in this case, 20C).
5000mAh = 5amps
5amps x 20(C) = 100amps continuous discharge
Using the maths, one may see that 100 amps can be continuously and safely pulled from the 5000mAh 20C LiPo.
If you want to just test using LiPo's to see what they will draw with an unknown C rating then get one of those LiPo fireproof bags to put your batteries in as you experiment. Exceeding the C rating may lead to fire.
2 motors never have exactly the same performance data so, no. You can't be sure they will share a load equaly.
Stall current flow for some little time at start. If a motor is blocked from running it will draw stall current while not spinning and quickly be overheated and destroyd.