sparkysx 125 Posted January 23, 2017 Does anyone know if I can link these two lipos together to make a 3s? thanks Share this post Link to post Share on other sites
sparkysx 125 Posted January 23, 2017 Oh and where would I attach the blue wire from the balance plug? thanks Share this post Link to post Share on other sites
BigAl69002 7 Posted January 23, 2017 No you can't link to form a 3s. Both the batteries you have are 2s, and linked together would make a 4s if series connected and 2s if parrallel conected. Share this post Link to post Share on other sites
sparkysx 125 Posted January 23, 2017 They aren't both 2s, as one of them is half of a saddle pack, it would only be a 2s with the other saddle pack attached. The 2s is 5000/60-120 and the saddle pack half is 5000/30-60 Share this post Link to post Share on other sites
Wooders28 4703 Posted January 23, 2017 I've a similar quandary, but mine are the same C rating, but different Mah (2s is 4300 and the half saddle is 5300). I'm presuming if you don't demand any more amps than the lowest C rating, then it shouldn't matter? Maybe raise the lipo cut off voltage in the esc to try and compensate for any difference between the cells? I wouldn't charge them together as a 3s though, that would be asking for trouble. 1 Share this post Link to post Share on other sites
sparkysx 125 Posted January 23, 2017 well the discharge is exactly half of the 2s battery, so when the saddle packs are together the ratings of both batteries are exactly the same. Share this post Link to post Share on other sites
Wooders28 4703 Posted January 23, 2017 Wouldn't that only be,if the saddle was linked in parallel, not serise? How I understood, 2S ("2"cells in "S"erise). The saddle is 3.7v, 5000mah and 30-60C discharge rate each. 2 saddle in Serise (normal way) = 7.4V , 5000mah 30-60C 2 in Parallel = 3.7v, 10000mah 60-120C 1 Share this post Link to post Share on other sites
sparkysx 125 Posted January 23, 2017 well I would wire it in series, so that should equal 11.1v. I already tried it (briefly) and the wheels were spinning a lot faster. Share this post Link to post Share on other sites
LongRat 616 Posted January 23, 2017 It would work in theory but I wouldn't trust the capacities to be matched (even though they have the same theoretical rating). There's the problem, because if one cell goes under min voltage but the other 2 are still over, you wouldn't get a cut-off but the low cell would be dead. Also, to be pedantic (but it is important) the one half saddle you have is actually a 3 cell pack (3P). So you have even more chance of balance issues and you couldn't detect it or do anything about it if it happened. 2 Share this post Link to post Share on other sites
sparkysx 125 Posted January 24, 2017 what about 3 matching saddle batteries? Share this post Link to post Share on other sites
Butler 338 Posted January 24, 2017 You need to be able to charge them as 1 battery to get them to balance properly, then you should be able to run them. If the capacities are the same or very close, then you need to wire them to together so you can balance them as 3s. Assuming 1/2 a saddle is 1s, and not 2s, but half the capacity. 1 Share this post Link to post Share on other sites
sparkysx 125 Posted January 24, 2017 either that or a saddle pack sized 3s, if such a thing exists? Share this post Link to post Share on other sites
LongRat 616 Posted January 24, 2017 I don't think anyone makes a 3S saddle battery. If you had three identical "1S" saddle units you could use them in the 3S config. In this case, if you want to be safe, I would probably charge each one separately as a 1S. You could also install a separate low voltage alarm on each saddle unit in the car if you want to avoid messing with making up the 3S balance wiring. 1 Share this post Link to post Share on other sites
MadInventor 3884 Posted January 25, 2017 For the cost of a factory made 3 cell LiPo I wouldn't muck about with it. You'll save maybe £25 over buying a new 3S harcase lipo from HobbyKing, but that'll be cancelled out if the home made battery goes poof when you're using it or charging and there's a fire in your model / garage............. 1 Share this post Link to post Share on other sites
sparkysx 125 Posted January 25, 2017 well only the wiring would be homemade, but I'm pretty good at that part tbh. I keep the lipos in an ammo box, but what could cause them to blow anyway? cheers! Share this post Link to post Share on other sites
sparkysx 125 Posted January 25, 2017 p.s, I don't need to save the £25, it's not about the money. 1 Share this post Link to post Share on other sites
MadInventor 3884 Posted January 25, 2017 9 hours ago, sparkysx said: well only the wiring would be homemade, but I'm pretty good at that part tbh. I keep the lipos in an ammo box, but what could cause them to blow anyway? cheers! I was thinking about using cells with mis-matched C ratings, maybe trying to charge it all as one lump. LiPo have been known to go bang / swell just under normal use. The other thing to consider is the chance of damaging the cells in an accident / roll over when using the model. I don't know what you're putting them in, but I've scraped up battery packs when trying to custom fit (bodge) batteries into cars they're not designed for or part built cars. If money is not a problem then I would get a 3S Zippy LiPo hardcase pack from HobbyKing. I just think it's job done in a neat package, and erring on the side of safety. Share this post Link to post Share on other sites
sparkysx 125 Posted January 25, 2017 they would be going in an Ansmann X2C pro, and all three batteries would be exactly the same ie: 3 of the smaller batteries in the picture above. Share this post Link to post Share on other sites
sparkysx 125 Posted January 25, 2017 this one? https://hobbyking.com/en_us/zippy-5000mah-3s1p-30c-hardcase-pack.html Share this post Link to post Share on other sites