Hi all,
What would be the recommended battery type and specs for the D845WP monster servo?
Thank you
Hey,
Well, for starters, this servo motor model is reported to be able to function with a wide range of voltage levels, from 4.8 - 8.4 V DC. If you want the best torque, we’d recommend using as high a voltage as you can.
This would be one of the following options:
]A 7 cells in series NiMH battery pack (~1.2 V DC per cell x 7 = 8.4 V DC)./:m]
]A 2 cells in series LiPo battery pack (~3.7 V DC per cell x 2 = 7.4 V DC)./:m]
]A larger amount of cells going through a step-down switching regulator to provide exactly 8.4 V DC (or lower)./:m]
That being said, the nominal voltage range seems to be 4.8-7.4 V DC, so we’d recommend sticking to that. Since LiPo battery packs tend to have higher discharge rates than equivalent charge NiMH, we’d recommend those for such a beast as this servo motor. It has a current draw of 30 mA @ idle, but around 1600 mA @ no load (powered) and about 10000 mA at stall!
Therefore, a simple battery pack like the RB-Sta-07 (LiPo, 2S/7.4 V DC, 2000 mAh, 5C) should be perfect for this use case. Since it has a capacity of 2000 mA and a discharge rate of 5C, it can output 10 A safely, which is what this motor needs in stall conditions (not a good place to be, but at least it would be very unlikely to damage the battery pack!).
Of course, if you have multiple of these motors in your setup, you may want to have more than one battery pack in parallel.
If you need a LiPo charger for 2/3 cell packs, we recommend something like the RB-Hui-06 as a simple solution. It offers 700 mA charging current, which would charge a 2000 mAh battery pack in under 3 hours.
We hope this helps.
Sincerely,