needed juice for my 645MG servos on a sparrowhwak

[gazzazh]

HI All, 

 

I am currently buying the stuff needed to start my build.. below are the specs:

1- seagull sparrow hawk 1.8

 

gear :

Dle 30cc

HD645MG 6 servos

2000mah for engine egnition

Ar7000 Receiver

 

 

what is the needed Nimh battery capacity for this setup to play it safe? 

[gazzazh]

would this do, or is it too much

[Frank Skilbeck]

Capacity is not the main consideration, you need to make sure you can delivery the amps, so I'd avoid high capacity AA packs which while fine at low amps can have a high internal resistance which means the volts drop off if you push them, I'd go for a 5 cell sub C pack or even a 2s LiFe pack if you have a suitable charger.

 

Edit - what you've shown above or something like this from a UK supplier

Edited By Frank Skilbeck on 30/11/2010 07:48:08

[gazzazh]

what about the link i made, its a a 5 cell sub c.. can you check please.. 

 

Thanks

 

With a lip i will need a regulator .. which i am not very keen on buying 

[Frank Skilbeck]

Yes see my edit, note with a LiFe cell you don't need a regulator as they are lower voltage than a Lipo, but you do need a compatible charger,

 

http://www.electricwingman.com/product.aspx?product=984

[Ultymate]

gazzah that battery you linked to would be fine sub C cells and plenty of capacity if not too much. There's no weight specified it will be quite heavy but provided your model can handle the weight it should be ok and save you buying either a regulator or charger You could go to 3000 mah and save a little weight but I'd stick with sub C's.

[Ultymate]

Have a look HERE there's a fair selection and they quote weights also

[gazzazh]

Thanks for all the info.. 

 

I think i will stick with the sub C.. i do have a charger, but from what i can tell the life Battery is rated at 6.6V... servos work at 6.0V.. which mean i will need a regulator.. which i don't want.

 

 

[Lee Smalley]

vapatex do sub c 3200 packs that are a tad lighter and will be more capacity than you will ever need for constant flying over an entire weekend i have not come across the packs you linked to i can only comment on the makes i use and eneloop and vapatex have been great 

 

on a note please modern AA cells are more than able to deliver the current we require for our servos please can we stop permeating the myth