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big daddy
08-30-2005, 03:59 AM
after 3 flights my gws 7.2/270mah battery packs will not fully charge! my charger is a mcr superbrain 959 with peak detection so it says the batt is fully charged but when hooked tho the plane just not enough umph to get her airborn! 2 packs worked fine at the field the the next time I tried to use them this happened?

Twmaster
08-30-2005, 04:06 AM
That's an odd one. These are Nicads yes? What plane are you flying them on? I have no experience with the Super Brain but had similar problems with an FMA Super Nova false peaking and not fully recharging my packs. You may try a different charger if you have one or can borrow/talk a flying buddy into letting you use his. Run the pack until the battery gets low then see if you can charge it a a very low rate to see if that helps.

Also, do you know what charge rate the Super Brain is using to charge that pack? It is possible that the pack is damaged from overcharging.

If you could post some more details like charge rate, type of plane/motor/etc. This may help lead to an answer. Without more details anything that might be mentioned is just speculation.

--
Mike N

big daddy
08-30-2005, 04:17 AM
yes nicd.I manually set the charge rate 1 amp. as low as it will go. I fly them in a stock gws tiger moth

Twmaster
08-30-2005, 04:22 AM
1Amp! :eek: Oh. Well that explains it. I think you killed your battery. Those cells will not stand a ~4C charge rate too many times. You need a charger that will go down to not more than about 300mA to charge those smallish packs.

I fly a Pico Stik F and use a GWS 350mA nicad pack. I set my charger to ~400mA for that one.

It's also good for pack life to allow a cooling off between use/charge/use. Heat is your battery's enemy.

big daddy
08-30-2005, 04:36 AM
:mad: this is the charger the jerk at the hobby store said was the best for what i was buying!!! This is what I thought might be the problem... what charger do you recomend? please think cheap as I'm out 70 bucks on the superbrain. also for future refference does the batt lose charge just setting for example charge at home drive to field will the charge weaken? if so will it hurt bATT TO Top off at field? Thanks for all your help

Twmaster
08-30-2005, 04:51 AM
Yikes. Unfortunately lots of stuff is sold that way in stores the world over (not just hobby shops). Well I posted some links to what I am using in the beginner's thread. Have a look. Batteries do lose some charge from sitting. However a short drive from home to your flying site is not going to drain much. Sitting overnight is worth topping off. Topping off a pack is usually not going to hurt anything as long as you are not blasting it with the wrong charger. :(

Sorry dude. A near new Super Brain ought to get you some of your money back on FeeBay or the for sale forum. Or you may want to keep it if you might get into cars or big bog planes.

big daddy
08-31-2005, 01:29 AM
I hear Lipos are another ball of wax.... You cant let them discharge too far or they are toast? Do you know anything about this? Because I may as well go lipo if I have to buy new stuff! What size batt do I get or my TM in stock form? I'm very frustrated plane flys great just want to get it in the air

debhicks
08-31-2005, 10:26 AM
Not to make excuses for your hobby shop dude, but unless they are electric specific and are keeping up with the in's and out's of electric, they are just retailers. What that means is their only goal is to get the cash out of your pocket. Appearently it works for some hobby shops, which baffles me. Especially since I work so hard to educate. I chase people off because I'd rather educated them and let them think about thier purchase. I know I loose sales because they use the education and then purchase on line somewhere not taking in to account the time spent with them by their local hobby dude. But I guess that is just life in retail.

There are some very good discussions on chargers and Red S. has everything you want to know about batteries at his website. It is worth studying. Sorry about your pack. Fortunately it was not a catastrophic happening as you may have with a lipo or a 70 dollar battery pack.

big daddy
09-01-2005, 03:19 AM
WE love the mountains of NC also! Ny family and I spend 3 vacations a year in the Smokies. My little girl calls the the GREAT Smokie Mnts! I'm sorry if I missed something But who is Red S and what is his web add? Thanks for your help!:)

debhicks
09-01-2005, 11:18 AM
Red Scholfield. He moderates on this board mMMMM Let me go find it for ya.

www.rcbatteryclinic.com (http://www.rcbatteryclinic.com)

There you go. There is an entire section on Batteries in this forum. But his battery clinic is there and if you have any other battery questions he can help ya out.

ZIGZAG
09-06-2005, 07:03 PM
Hi
The jerk at the hobby shop ????????????????????????
It did come with instructions ??????????????????????
ZIGZAG

big daddy
09-10-2005, 12:58 AM
The directions were useless. Basically said plug it in and let it go since it was a peak detection charger it should work by its self? FYI if any of you live in the greater cincinnati area it was Pit Row in Kenwood the guy knows nothing about E flight just tells you something to make a sale

Twmaster
09-10-2005, 02:11 AM
We have a couple of hobby shops like that here. Needless to say I don't shop there. :(

big daddy
09-12-2005, 02:49 AM
I'm looking into a new charger {electrifly polycharger} for a cheap way to start using lipos it has 3 settings 250 500 1000. sooooo can I only use it with batts that have that much mah? soooo it would be useless with a 640 mah or a 1500 mah batt

Twmaster
09-12-2005, 02:56 AM
I have one of those Poly Chargers. It works fine with any 1, 2 or 3 cell LiPo. Just charge a bit slower on some batteries. For example charging at 500Ma on a 640Ma pack.

I use it with my 640 and 700mA Kokam packs.

big daddy
09-12-2005, 03:02 AM
can I ask how long it takes to charge those packs and how do you know when its time to land the plane before you damage the batt from to low of a discharge?

Twmaster
09-12-2005, 03:07 AM
I think it takes about an hour to charge the 640 pack. My memory is fuzzy and I never timed it. As for the cutoff you should use an ESC compatible with LIPO which will have the correct cutoffs

big daddy
09-12-2005, 03:18 AM
one more question, do I have to use a esc that is "lipo compatable" or can I get by with stock gws esc? when you say lipo compatible do you mean brushless compatable? is there a diff? Sorry about all the questions I just don't want to get burned again

Twmaster
09-12-2005, 03:24 AM
Hehe, no worry on the questions. This is how we all learn. :D

What I mean is an ESC that understands LIPO batteries. For example the Castle Creations Pixie series which are designed for brushed motors like your Tiger Moth has. I know folks who run their LIPO cells on non-LIPO ESC's. What you need to do is try to determine how much flight time you can get before the cells are discharged too far. This takes a bit of work and can be done. However from my point of view it's a real pain to try and keep track of the time and such so I just use the right ESC for the job. A Pixie-7 will be more than enough for the TM.

For the record I fly my Pico Stick-F and Light Stik on 6 and 7 cell 250MA NiMH packs these days. The LIPO packs are on my other birds in the fleet.

big daddy
09-12-2005, 03:36 AM
are there any chargers out there that do both? remember affordable

Twmaster
09-12-2005, 03:43 AM
Define affordable.

There are a couple (or more) good chargers out there that do both. The Triton is one, AstroFlight also makes one. IIRC the Triton is around $125 new. Not cheap but does the job. I use two chargers. I have one for nicad/nimh and one for LIPO. I like it because I can charge two batteries at a time this way. Your wallet may vary.

:D