Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: TrickyNekro on August 11, 2008, 06:06:01 PM

Title: Do RC Lipo Batteries need protection when on the model?
Post by: TrickyNekro on August 11, 2008, 06:06:01 PM
Hello guys...


Today I got my first fully acrobatics helicopter and I try to fit it up with all the RC staff...
I got some really nice questions but really one can be really money saving...

Does the batteries need protection cause they are LiPo's... meaning that I don't want to go under 7V6 as written...

The ESC is a BEC so I don't think that the reciever can waste up so quick.... but the ESC works between 11V4 and 7V2...
can this be a problem...

I short work... do I need to make a protector... it's not that big deal since I got some nice free samples from Maxim... but you
know it's still summer time and I get really lazy...


BTW... Getting the heli was a big part of the UAV I like to build... get a hold on... I think that by December I can write up a really nice
tutorial on UAV.... complete!!!
GPS, object avoidance,,,,,, get a holda!!!

With all do respect, Lefteris
Greece
Title: Re: Do RC Lipo Batteries need protection when on the model?
Post by: GHF on August 14, 2008, 06:15:32 PM
Oh yeah, you still need them. RC LiPo's don't have protection like a cell phone battery would, to save weight.

Does your ESC have a cut-off circuit? It could save you some work. My brushless ESCs are programmable, and they can be set to either auto-detect the number of lithium cells and calculate the cutoff, or cut off at 5.0V (to prevent radio failure, for non-lithium batteries).
Title: Re: Do RC Lipo Batteries need protection when on the model?
Post by: TrickyNekro on August 16, 2008, 12:26:19 PM
I think it has but I won't risk it...

Bet it... I'll build my own, can't be buying everything... lol!!!
I guess some samples from Maxim will do... the have many protectors supervisors...

Another question now...
Can I parallel place two mosfets to enable larger currents lower heating of a single mosfet and even lower resistance...
Although I think I won't need such placing... it's good asking...

Thanks for the repply,
Best Regards
Lefteris, Greece
Title: Re: Do RC Lipo Batteries need protection when on the model?
Post by: Admin on August 22, 2008, 10:36:04 PM
Quote
Can I parallel place two mosfets to enable larger currents lower heating of a single mosfet and even lower resistance..
Yeap, you can.