90 mm 8s

[jetlag]

Need help with 90mm 8s set up in F15c, seems there is a few. Use 2 - 4S/5000 or 2 2S/5000 & 2 6S/5000. Wont the 6S try to charge the 2S ? And will I need to carve foam, couldnt find a post for this so any help is great

[F106DeltaDart]

Need help with 90mm 8s set up in F15c, seems there is a few. Use 2 - 4S/5000 or 2 2S/5000 & 2 6S/5000. Wont the 6S try to charge the 2S ? And will I need to carve foam, couldnt find a post for this so any help is great

That would be true if you set the batteries up in parallel. To get 8S, need to connect them in series. This is essentially the same way that the cells are hooked together in a typical pack, combining them to get a higher voltage rather than higher capacity. If they were done in parallel, you would need to use packs of the same voltage, but you would get more capacity, and therefore flight time. Let me know if this makes sense, and I'll do my best to help you out! Can't answer on the foam carving though since I don't have an F-15.

[jetlag]

No i understand, I read your post and put 2 lipos next to another and it hit me like a brick. Thank you, now for 8s answers hopefully

[rcftrguy]

Hello Jetlag,using two 4 cell batteries in series for 8s is what I use consistently, but my advise would be to ensure that they are close to 50c batteries as this will allow for 250 amp max draw. (50cX5000mah =250000mah or 250 amps) ideally if you can oversize your ESC and Batteries by 20% of the estimated load, you'll have less issues...
I would also ensure a 1/4" space from battery to foam side for air circulation. I use a rounded grinder bit in my dremel tool to carve foam, it works great. If you need to carve more than is structurally allowed, reinforce with epoxy and fibre strips. Best of luck and hope this helps....

[jetlag]

It does, can you post a pic of batteries in fuselage?

[rcftrguy]

Unfortunately I do not have pictures, I no longer have the F15. I have the 8s setup in my Fiberglass Habu 32 and the batteries are setup end to end, not side by side.

[jetlag]

10-4 so 2 4s/5000 50c side by side. Thank you sir

[jetlag]

I have a taft V3 Super snake id l8ve to put a 8s freewing set up in

[gooniac33]

As long as the packs are the same Capacity and C rating they will be fine. You can use a 6s pack with a 2s pack. Or a 5s with a 3s pack, or what every combo you have so long as capacity and C rating are the same.