Battery for servo drive

earthwormjim · Post by **earthwormjim** » Tue Mar 29, 2011 3:53 pm

Hi,y'all.
I am building a flea,using standard servos,and a hobbyking cheap 4ch RX. No weapon. For a battery,I wanted something small and light.
I want to use either 2x 60mah 15c lipos
Or 2x 90mah 5c lipos.
I am using these servos...Turnigy S3317B Servo 19g / 2.5kg / .14sec
This is supposed to be a rammer/pusher,so power is of the essence.
My question is,will run time be affected much,and will there be any difference in power between the two options,or will that all be filtered out through the RX?????
It is running well at the mo,on 180mah 15c lipos,I dont want to make it too feeble!
(I do realise that there are probably one or two stupid questions buried in there,but was hoping that they would be masked by some waffling.

)
Many thanks,Jim.

haz · Post by **haz** » Tue Mar 29, 2011 4:00 pm

do you mean ant? two 19g servos would be hard to do a flea with

earthwormjim · Post by **earthwormjim** » Tue Mar 29, 2011 5:15 pm

That is twhy I am looking at small lipo's!!!

haz · Post by **haz** » Tue Mar 29, 2011 5:25 pm

remember that they will be bigger too

josh · Post by **josh** » Tue Mar 29, 2011 5:36 pm

http://www.hobbyking.com/hobbyking/stor ... oduct=7566

wire 4 of these together, two sets in series linked in parallel. to make a 140mah 20c 7.4v pack with 4 cells that are 18x14x6mm each or even maybe get away with just one 70mah set

peterwaller · Post by **peterwaller** » Tue Mar 29, 2011 6:15 pm

Both my fleas are running on two of these.
http://www.hobbyking.com/hobbyking/stor ... oduct=7567
7.3 gms with connector.

earthwormjim · Post by **earthwormjim** » Tue Mar 29, 2011 6:28 pm

I was going to use 2 of these...
http://www.atomicworkshop.co.uk/catalog ... cts_id=181
L=22mm W=13mm H=4.5mm, Mass 1.65g.
If 60mah is enough????

peterwaller · Post by **peterwaller** » Tue Mar 29, 2011 7:10 pm

I personally thought 100ma was likely to be too small having said that on Fleabite it is running 2 50:1 HP motors and the spinner. I did recharge after every battle. The lower the capacity and lower the C rating the more likely the internal resistance is higher so not only will they last less time the voltage out is going to drop more as you draw current so less power.

earthwormjim · Post by **earthwormjim** » Tue Mar 29, 2011 7:36 pm

Thanks Peter.
Typical.the 100mah are out of stock!

earthwormjim · Post by **earthwormjim** » Wed Mar 30, 2011 4:38 pm

ordered 2 90mah lipos.
And the modded servos have gone from 19g,to 13g each.
I am using the servos that were in "duff" at the last AWS,as I drove it in the robot roulette,and it was great fun.A bit quick,but great fun!

I have broken 1 rx,and 5(!) servo control boards today. I have ordered 2 more servos from hobbyking to pinch the boards out of!!

I did get a quick test drive and it is going to be stupidly fast! Should be fun!