2X3S = 6S? Lipo question

[machasm]

Hi All,
I am currently looking at getting a hold of a TREX 500.
I already have a couple of 450s and as such have around 7 or 8 3S LIPO batteries.
Now the 500 uses 22.2V which equates to a 6S battery.
My question is is it possible to use 2 11.1V lipos in series?
Just seems that if I have these cells then why not use them.
Wether I can get them to fit into the 500 is another issue though.
Thanks.
Adrian.

[Boggy]

i think the answer is yes mate thats what the 500 was originally designed to use!!

[raptorheli2]

yes you can use them assuming they are not some weird size pack. you don't say what the packs are but anything that fits the 450 will work ok doubled up in the 500. the mimimal you want imo is 2100's for 6s. you will get a short flight time with these however. 4-4.30 mins.

cheers

[machasm]

Thanks for that guys.
I have a couple of EVO LITEs 2500 20C.
Do you think they will do?
I am assuming that I need to buy/make a connector to join them together.
Adrian.

[machasm]

Also what happens if you marry different packs together.
Say a 2100 with a 2200 or 2500 pack?
Adrian.

[Ian]

Hello Everyone,

marrying up 2 3 cell packs is perfectly fine IF you follow some simple guidelines. first off, if you have one old pack from your 450 and you go buy a new pack with the sole intention to put them together, to save money, you would be wrong, very wrong. you will kill both packs no questions.

if you want to put 2 3s packs together, here are some simple guidelines to follow:

Use only the same brand and same capacity and same "C" rated cells.
Use packs of simular age. i dont mean to the very last mAh, but i mean if one has 10 cycles, one has 50, then thats not good, if one has 10, the other has 15 MAX! then its OK. try keep them as same as possible.
When using them as 450 packs, then putting them together as a 500 pack, balance charge them individually to full, and then fly as a pair, the next charge, charge as a PAIR while balancing as 6 cells, then use as a pair. this is vital.

its just common sense really, but it is very easy to kill both packs with a simple mistake. 6s packs are really the way to go, but of course, if you have 2 simular age 3 cells, why not make use of them?


Ian
Electric nut and FP tech support bloke

[Ian]

Also what happens if you marry different packs together.
Say a 2100 with a 2200 or 2500 pack?
Adrian.

dead packs, see above

[Leebert]

Just to add, I was using 2100 18C 3s packs on my 500 and they weren't really up to it IMHO. I'm a sport flyer running a 13th pinion.

I think a 2500 20c pack would be a good minimum with 25c prefered. That does require the batteries 'C' rating to be genuine and not just a marketing ploy of course