Battery question

[KeithT]

Guys - had my Esky 1500mAh stock battery die on me today (maybe that small crash did more than I thought) I looks ago with no visible damage, but says there is a volume error on charging and the cell voltages fluctuate wildly.

I have several of the 3s 2200 mAh lipos that I use in the 450.
I am running a stock K3 motor with a Turnigy Plush 30A ESC.
Could I use those big lipos safely??
Wisdom please

KT

[Wrench 54]

Hey Keith, you can check the V of each call with a volt meter and pointed probes if you have one, on the ballance plug you put the probes on two side by side pins and move both the probes one spot across the ballance plug at a time to read each cell by its self, this will tell you if you have a bad cell or maybe one of the wires had come off under the top cover, which can be fixed ( re soldered ) but you must be real careful cutting open the cover not to short out anything, this may be causing your charger to act funny, I've had batts that broke one of the ballance wires under the top cover and they wouldn't let my chargers even kick on, as for the 2200mah batts I heard of members running them but they are a lot heavier than the 1500mah and I'm not sure if they will fit in the front of the stock K3 frame or if you can get the canopy on also, what the heck give it a try and see what happens-------Wrench

[KeithT]

I'm just discharging it at the moment - will see if it recovers and will re-charge.
I think a cell is down - a wire off may well be the reason. I have one of those cell testers so I'll stick that on and see what it tells me.
The K3 is not the stock frame it's the CF one so I'll check what fits and (perhaps) see if'n it works. Don't want to blow any electrics Thanks matey

[KeithT]

Ok - had a close look after the cell tester said cell1 was 000 - the yellow wire is detached.
It's all under some protective cellophane casing - if I cut into that, am I likely to get into trouble?:o I could re-solder that connector - result would be battery ok. If I get it wrong - result = fire
Hmmm

[Big Tonka]

Hi Keith I am running a 3900 motor and 30A esc on my K2 and I run 2200mAh in it all the time and get some great flight times from them, I have also found that on the K2 the larger batt help with the CG and bring the heli nice and level for flying, as for the re-soldering the wire on your batt sorry but never tried it I would think that as long as you dont allow to much heat to pass into the cell you will be okay.
Hope this helps.
BT

[KeithT]

Yeah BT - thanks mate it does
Will think seriously in the cold light of day about soldering what is, after all, an Esky 1500 mAh battery May well NOT be worth the angst
I have 5 of the 2200 mAh batteries just waiting to soar.
Cheers buddy

[exblade]

Keith,

I had a battery do that and if you carefully take a hobby knife and cut the tape or covering upward, away from the battery enough to get at the wire and board to solder it, it will work fine. Just stay away from the silver battery bag with your knife and or soldering gun. I re-taped mine with duct tape.

BTW, I had a cell explode in flight one time in my King 2. It must have been a motor short or something. The ESC survived, but the battery blew apart. Lipo juice everywhere, but NO FIRE. I don't go out of my way to let that stuff leak, but it appears to be less than the nitro glycerin it is made out to be. Once ignited though, look out!

Terry

[chrismechanic]

hey all...+1 on that terry. had this on an esky lipo too, easy fix just be carefull with the cutting.
i cut through the green band at the bottom and the yellow tape at the top. take out the flap of silicone rubber and your good to solder. i taped mine back together too then used fresh shrink wrap to do the whole lipo.
chris

[KeithT]

Will give that a go later today.
I have cut through the yellow tape, but not yet removed it.
Steady hand this afternoon all being well.
KT

[likeakite]

So did you scrap it? I have three very old 1800mah, football shaped batteries that are used in the stock K-3 with the 25amp esc, and then have started using the 2200mah when needed. Havent noticed any excess heat in the esc or wiring, so i think its fine. It sure does increase fly time nicely too.

[KeithT]

Not yet Lak - gonna get to it shortly.
Just having some caffeine to steady my nerves.
I hate lipos (just scared) - one of the compelling reasons for the nitro conversion.
I didn't like the thought of 6s monsters tbh

[KeithT]

Ok guys - job done
Good grief I had to pump some heat into that puppy to get the solder to melt
Finally got it done when the iron tip got to 480deg C - wrapped it all back up nice & tight - cells all give a reading and the battery is currently (pardon the pun) in a lipo-safe bag under a gentle charge at 1.5A - cells look in reasonable shape so that's a first for me.

Thanks for the help & support fellas
KT

[abbywed]

Brave man to solder a lipo.. if done right you have a working $10 battery... if done even a bit WRONG... lets just say I solder ANY lipos outside away from the house,shed,helies,cars,boats,dry stuff, wet stuff, any-stuff...You only get one chance at getting it wrong and it can go horrobly wrong Very Quick. Lipos are Leathal. if you dont beleave this just do a youtube search for lipos...Fun?

[Wrench 54]

Very Good Keith, I've had a few batts break a wire and it's funny it's always the yellow wire, the first time I did one I was like you just not sure if I was treading on rocky ground but it went ok and I and the lippo survived, even had to fix one of the 6S ones for the 500 and yep you have to have a very steady hand with the soldering gun, glad it went well and keep an eye on it for sure-------Wrench