TonyS Posted September 5, 2009 Share Posted September 5, 2009 I've been using Overlander Extreme 'Fullymax' constant 35C 3S LiPo's for my models as I figured when I was buying them for the EDF the motor would draw quite a chunk off the battery and the 1700 was the only one that fit into the rather tight battery bay on my F-9F. (Shame the plane didn't last long enough to test the life of the battery...) All the ones I've bought have been 1700mAh and I've been looking for something a bit bigger 'cos I just tested my Funjet with my new wattmeter (did I say I just got a new wattmeter ) and at WOT the battery will last an astounding.....4 minutes. Before I invest the equivalent of another month's mortgage payment on a new battery can anyone tell me - do I need (or is it useful) to have a battery capable of a constant 35C? I've noticed that most - Kokam, Tornado etc etc seem to settle on 20C or 25C. Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted September 5, 2009 Share Posted September 5, 2009 tonys-timbo is your man here-send out a call for him---before you spend any more dosh......... timbo's agent ken anderson......... Quote Link to comment Share on other sites More sharing options...
TonyS Posted September 5, 2009 Author Share Posted September 5, 2009 Thanks Ken, S'funny but I thought that might be the case. I just don't like to seem too demanding on Timbo who's been very helpful with my pretty constant questions. Some days I feel like a kid again....why does this do that? ......yes but why? etc etc Blinkin good forum though and getting me off to an excellent start with modelling again. Oh, and my good lady just told me I'm getting a Yak 23 EDF kit for my birthday.....I'm so excited!!!!! But look out 'cos I'm sure that this will lead to buckets more questions. Off on hols tomorrow for a couple of weeks. I'd rather stay and build models but given how good my missus is I think I should look willing..... Think I should do a build blog on the Yak...? It won't be anything like as impressive as the Wasp and others but might give a few of you a good laugh... Quote Link to comment Share on other sites More sharing options...
andy watson Posted September 5, 2009 Share Posted September 5, 2009 Build blogs are always worth doing- there will always be someone following behind that can learn from your mistakes!!! Quote Link to comment Share on other sites More sharing options...
TonyS Posted September 5, 2009 Author Share Posted September 5, 2009 LOL - sounds like you already know me!! You guys are sure going to learn a lot on that basis Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted September 5, 2009 Share Posted September 5, 2009 It depends really on what current you are likely to be drawing. For example:The rig pulls 40 A, you have a 4000m/a battery 20C rating. At 40A thats 10 X its capacity = therefore its being used at 10C....half its capability At WOT that will last 6 minutes. ( 60 / 10 = 6 ) The same exact rig ...you have a 4000/ma battery at 30C ratingAt 40A thats 10 X its capacity = therefore its being used at 10C....1/3rd its capabilityAt WOT that will still last 6 minutes. ( 60 / 10 = 6 ) Huge C rates ( some of which are untrue anyway ) are only really necessary where very high current is required, but the model / budget cannot cope with a huge capacity battery. EDF - pulls 60A - battery 3000m/a 20C ( 60 A maximum discharge )60A is 20 times its capacity, and its absolute maximum capability. It will not have a long life, and will be likely to sag under a 60A load. flight time....3 minutes Ditto, but the battery has very high C rate of 40C ( 120A maximum discharge )60A is again 20 times its capacity, but only working at half its capability.Pack will have a longer life, and maintain a good high voltage under the 60A load Flight time remains the same of course....3 minutes.Get it ? Quote Link to comment Share on other sites More sharing options...
TonyS Posted September 6, 2009 Author Share Posted September 6, 2009 Got it. I knew I'd get there in the end....with a little help of course Thanks. Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted September 6, 2009 Share Posted September 6, 2009 3 big cheers for timbo(well 2 and a half)........... ken anderson........... Quote Link to comment Share on other sites More sharing options...
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