john stones 1 - Moderator Posted November 7, 2017 Share Posted November 7, 2017 Whats it mean 4S1P and 4S2P ? Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted November 7, 2017 Share Posted November 7, 2017 4S1P means 4 cells in series, 4S2P means two sets of 4 cells (in series) in parallel. S= number of cells in series P= number of parallel trains So 4S1P is 4 cells total, 4S2P is 8 cells in total (2 x 4). Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted November 7, 2017 Share Posted November 7, 2017 4 cells in series and 2 packs of 4 cells in series paralleled together (same voltage, twice the capacity). Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted November 7, 2017 Author Share Posted November 7, 2017 Thanks fellas, not my strong suit lecktrickery, which pack would be best for a starter battery ? Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted November 7, 2017 Share Posted November 7, 2017 As they are the same capacity and C rating, I'd go for the 4S1P as there is less chance of in-life failure. I use retired LiPos that have got to the point where they don't give good flight performance - they are effectively free* - but use a 3S unless you have a 12 - 24V capable starter... *Should appeal to a Yorkshireman? Edited By Martin Harris on 07/11/2017 16:34:57 Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted November 7, 2017 Share Posted November 7, 2017 I use both a 4s LiFe (A123 cells in my case) and old 3s lipos to drive my electric starter, either would work great, might be worth asking if any of your fellow electric fliers has got any 3s lipos that they aren't using, something like a 3s 2200+ mah would be good for the job, or the 4s1p you identifed earlier would do the job, just remember to set your charger for LiFe cells when charging it. Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted November 7, 2017 Author Share Posted November 7, 2017 Starter will be o.k on 4s life rated to 15v, me being thick skinned and never having had a lipo go pear shaped on me, I'd sooner have a life fastened to starter whilst I'm using it..just in case. I've some tired 3s Lipo's if you want them though. thanks Martin. Quote Link to comment Share on other sites More sharing options...
Don Fry Posted November 7, 2017 Share Posted November 7, 2017 Being a hooligan, I habitually use a 4S lipo with a common or garden cheap starter, 12v. On a small sample, accepted, but it hasn't broken in three years of use continual use, nothing over 38cc, and I note, it uses little power, because the increased oooomph goes to low current use when the back emf kicks in? Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted November 7, 2017 Share Posted November 7, 2017 I use a 2650 mAh 6S lipo rewired to 5S (long story involving some wrong info from HK, yet another electric dead stick, some smoke and a warranty claim) to power my Just Engine geared starter, a great bit of kit which would probably start a Merlin with a bigger rubber cone...sorry, my Mum's told me a million times to stop exaggerating...but it hasn't baulked at anything I've tried it on. Although the motor is rated to 24V, my experience is that it isn't the same case for the switch, so 18.5V nominal is ideal. I probably charge it 3 times a year. Edited By Martin Harris on 07/11/2017 18:09:39 Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted November 8, 2017 Share Posted November 8, 2017 A 3S Lipo will easily power a starter John....I have a very old & tired 3S 2200mAh on my ancient Sullivan starter & this spins up to a 15cc 2 stroke with ease...certainly much, much better than the 7Ah SLA battery I used to use... Quote Link to comment Share on other sites More sharing options...
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