Best Battery for a qik 2sv9

So i am using a polulu qik 2s9v1, with 2 … rmd%3Divns ( i do realise thats a long link )

Im wondering what the optimum or close to optimum battery i can get for this setup, to produce enough speed out of the motors.



Your lack of details makes it impossible to give you any meaningful advice. For example, what does “enough speed” mean? If all you care about is providing enough current for your motors, plenty of batteries will fit the bill. Selecting the “optimum” one will depend on other constraints of your application (e.g. size, weight, capacity, cost, chemistry, etc.). What voltage do you want to run the motor at and what is the stall current at that voltage?

- Ben

Thats my problem. i need a high current rechargable battery, wth a long life. as far as the application - powering 2 of the motors above ( stall current cannot be supplied as i need the actual battery to measure that) and by speed i mean having the motors reach a decent rpm, well within their range of movement

You keep using subjective specs, like “long life”. For some people that might mean 30 minutes of constant use and for others it might mean many hours. In order to compute how long a battery will last, you need to have some sense of your average current draw. Maybe you should just purchase the highest capacity battery you can easily find? The maximum speed of your motors should vary approximately linearly with your battery voltage; if it ends up being limited by your battery’s ability to supply current, you have chosen an inappropriate power source for your robot.

It sounds like a 4-cell NiMH battery pack (4.8 V nominal voltage) could work for you. Our highest capacity pack is made of AAs and has a capacity of 2.2 Ah, which means it can deliver (approximately) 1.1 A for 2 hours, 2.2 A for 1 hour, 4.4 A for 30 minutes, etc. Your motors should also be able to tolerate 3- or 5-cell NiMH packs. You can find higher-capacity NiMH packs on common RC hobby sites (try searching for “sub-C”; sub-C packs can have capacities around 4000 - 5000 mAh).

The batteries with the highest energy density are lithium-based rechargeables, so you might also consider using a single-cell LiPo pack (3.7 V), which is at the low end of your motor’s voltage range, or a double-cell LiPo pack (7.4 V), which is above the maximum 6 V rating for your motors. They might be able to tolerate this higher voltage, but I cannot promise that, and it would still probably shorten their lifetimes.

You might find this blog post on battery capacities helpful.

By the way, depending on the stall current of your motors and the way you plan on using them, the qik 2s9v1 might not be an appropriate motor controller. It can only deliver a continuous 1 A per channel and handle current peaks of 3 A (also per channel).
- Ben