HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Dec 18, 2012, 11:04 AM
Registered User
Philippines, Calabarzon, San Pedro
Joined Jul 2012
4,483 Posts
Discussion
How do you prepare your batteries?

Lately i noticed that my GeniusCP could no longer pull out of a hard turn after only a few minutes on a 350mah battery and ends up dragging the skids across the ground (ouch!). They still lasts 8 minutes before the heli could no longer get off the ground (usually fly all the way 'til 9 minutes). I got these four batteries back in september and have been flying two or three times a day lately. So that would make about 50 cycles each. I thought lipo's are supposed to last hundreds of charge cycles so it seems to be too premature for these to have worn out. The only thing i can think of is that they may be too cold.

How do you guys get your batteries ready before a flight? Do you recharge them next to a heater? Put them on a thermos while packing up? Leave them in the sun? Put them on top of a toaster? Maybe i should pack a hot water bag in the carrying case next to the batteries?
Hajile is offline Find More Posts by Hajile
RCG Plus Member
Reply With Quote
Sign up now
to remove ads between posts
Old Dec 18, 2012, 11:18 AM
Registered User
United States, MO, Springfield
Joined Jul 2010
3,510 Posts
8 min is pushing it a 350mAh pack
mostlikely you have over dischaged the pack to many times and its not holding full change any more

solution? get new packs and dont fly more then 5 min on them
as a rule dont dischange more then 80% of rated if you want your packs to last
how do you find out how long that is? well fly some time that is fairly safe 3 to 4 min for packs that size
put it on the changer and see how much you put back in; this will require a good changer with a display at lest an icharger 106b for small packs like that
you shouldnt be putting back more then ~280mAh ideally no more then 250mAh more then that and your packs wont last very long
Elios000 is online now Find More Posts by Elios000
Reply With Quote
Old Dec 18, 2012, 11:30 AM
Registered User
Philippines, Calabarzon, San Pedro
Joined Jul 2012
4,483 Posts
I thought the rule was to not let the batteries go below 3 volts? I have two of the discharged batteries in front of me right now and they register 3.7v each. Which is typically the voltage where the GeniusCP turns itself off. The other two are still full and they both register 4.2v.
Hajile is offline Find More Posts by Hajile
RCG Plus Member
Reply With Quote
Old Dec 18, 2012, 11:42 AM
Newbie but coming on fast
KYChopper's Avatar
United States, KY, La Grange
Joined Jun 2012
143 Posts
Elios000 is spot on, follow his advice and your batteries will last longer. The 80% rule is on capacity, not voltage. Check the battery forum where you can learn more about this topic.
KYChopper is offline Find More Posts by KYChopper
Reply With Quote
Old Dec 18, 2012, 12:01 PM
Registered User
United States, MO, Springfield
Joined Jul 2010
3,510 Posts
wile the packs may be charging up to full voltage still there useful capacity has been reduced
the 3v rule your thinking only applies UNDER LOAD
if your taking them down to 3v unloaded chances are under load its much lower maybe under 2v even

tl;dr if your flying to LVC your killing your packs
LVC is a safety to keep from totally wreaking the packs its not a timer
Elios000 is online now Find More Posts by Elios000
Reply With Quote
Old Dec 18, 2012, 12:18 PM
Registered User
Philippines, Calabarzon, San Pedro
Joined Jul 2012
4,483 Posts
Crap. I wish i'd known that before i lost four batteries.

I have three more 350mah on the way (Different brands, so i can see if there's a difference before buying four more of the same) and i just have to set the timer to five minutes for each of them right?

Atleast the 2200 is in storage, i've only run that down a couple of times. I could only keep the 450 in the air for a few minutes before i call it a day and switch to the GeniusCP. How long's the recommended flight time for a 2200mah on a 450 sport?
Hajile is offline Find More Posts by Hajile
RCG Plus Member
Last edited by Hajile; Dec 18, 2012 at 12:27 PM.
Reply With Quote
Old Dec 18, 2012, 12:23 PM
Registered User
United States, MO, Springfield
Joined Jul 2010
3,510 Posts
im guessing
best thing is set a timer for 4min pretty much a safe time
then change them and see how much power you put back
if its less then 250mAh (for a 350mAh pack) then add some time till your putting back around 250mAh to 270mAh
then - 30sec to a min
this is what i do for my big helis i can get ~6 to 7 min putting back 80% in to the pack
but i run my timers around 5:30sec for 2 reasons 1. i have at least 30sec to a min of extra hover time if say some one has a dead stick when im getting to the end of a pack i can hover till they get on the ground(not an issue with our micro since your not flying it on a flight line)
and 2. im pretty much ready to land after 5 min lol

i found when i had a mCP X that i could only get maybe 2-3min of good flight time out of it be for the pack fell off to much
so you may want to start there i dont know what your flying style is like but i would run a small CP heli at 100% in idle up
Elios000 is online now Find More Posts by Elios000
Reply With Quote
Old Dec 18, 2012, 01:01 PM
Registered User
Philippines, Calabarzon, San Pedro
Joined Jul 2012
4,483 Posts
I'll have to figure out if it's possible to roughly compute for the mah using a watt mater. I guess my next purchase next month is this.

http://www.ehirobo.com/shop/Batterie...duct_info.html

Imax B6 Charger Review (15 min 43 sec)


It shows the mah at 12:30

And i'm using a V-curve 100-80-100
Hajile is offline Find More Posts by Hajile
RCG Plus Member
Reply With Quote
Old Dec 18, 2012, 02:14 PM
Closed Account
Joined Dec 2007
6,549 Posts
Quote:
Originally Posted by Hajile View Post
I thought the rule was to not let the batteries go below 3 volts? I have two of the discharged batteries in front of me right now and they register 3.7v each. Which is typically the voltage where the GeniusCP turns itself off. The other two are still full and they both register 4.2v.
3V is the damage point, so you don't want to go anywhere near there. It's like waiting for the low oil light to come on before changing the oil in your car.

Use only 80% of the capacity which is 280 Mah, and your lipos will last much longer.
Xrayted is offline Find More Posts by Xrayted
Reply With Quote
Old Dec 18, 2012, 02:28 PM
V120D02S, GCP
LarsDennert's Avatar
United States, CA, Pasadena
Joined Feb 2012
142 Posts
Yep if you are discharging below 3.7v, throw out the batteries. Don't fly until the bird starts to falter. At that point you are killing the batteries. I flew with 240s. 350's must really add weight to that poor little heli unless it is converted to BL. Don't store the batteries full either. If you are not BL, let the motor rest between batteries. The gcp gets hot and 350's will make that part worse in both weight and longer flight time. 6min should be fine though.
LarsDennert is offline Find More Posts by LarsDennert
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Looking for Ideas! How do you keep a log of your batteries? Titus Gordon Batteries and Chargers 11 Sep 14, 2012 11:50 AM
Discussion How do you mount your battery and receiver in a DLG? Fly2High Hand Launch 11 Jul 24, 2012 05:06 PM
Question How do you take your Lipo batteries to the field? Left Coast DJ Batteries and Chargers 26 May 26, 2012 06:02 PM
Discussion How do you clean your transmitter? mams1 Australia 27 Mar 18, 2012 10:45 PM
Question Where do you get your trim designs and how do you test them? dedStik The Builders Workshop 16 Mar 15, 2012 04:32 PM