Batteries.

[Donziikid]

Howdy Xmodsource members,

This is a sad and frank reminder thread that all batteries can be dangerous, no matter the chemical make up. Below you will see why..

Today I ran the RC18MT like any other day on the stock NiMH batteries. After they were reaching the end of their charge cycle I noticed a little jitter with the throttle; which I never experienced before with the same setup. I wrote it off as a glitch and stopped the RC18, went inside and took the battery out and gave it a good once over as well as cleaned her. After about two hours I decided it was time to drive her again, so I plugged in my batteries. Typically, my batteries take about fourty-five minutes to charge at 1.0amp; today, however, it was taking longer. After about the hour and fifteen minute mark I stopped to examine the cells..

Unknowingly I picked up the pack by a fistfull, initially thinking they're just going to be luke warm. To my dismay they were actually leaking acid and scolding hot. I couldn't smell anything from my computer desk, but as I picked up the pack with my bare hand I could notice the foul smell as well as feel the gooey substance running up my fingers. Immediatly I yanked the battery from the charger and ran to the bathroom to wash my hands with cold water; unfortantly I'm still left with a minor burn and one less battery pack.

Below are the images of the faulty cells. Unfortunatly I am left with only two more packs.. I have come to the conclusion that I charged these batteries at too high of an amperage (1.0amp with them being 1100mAh batteries) which caused them to become faulty and lead to some sort of short within. I should take the same precautions with NiMH that I do with my LiPo, but, unfortunatly, I do not and this is what can happen..




Consider this a friendly warning from your neighborhood Donziikid. It would be unfortunate to see anyone go through the same experince because of faulty cells, so please be careful; whether they're radio packs for a Nitro or expensive NiMH/LiPo batteries for an electric.. I know none of you want your mother on your *** for having cells "explode" in your room.

Cheers,
Kyle.

[2wdpancar]

0.0 That's gotta blow dude..
Dang, that think just totally comitted suicide!

And, if worse comes to worse with LiPo, throw it in a fire escape or something..

[Donziikid]

Originally Posted by blt456

0.0 That's gotta blow dude..
And, if worse comes to worse with LiPo, throw it in a fire escape or something..

"That's gotta blow dude.." No pun intended, right?

I live in Michigan, in a two story house, in a subdivision.. I don't have a fire escape. If my house catches on fire, I just have to run through it all and hope I make it out the front door.

My LiPo/LiIon charging is always done in the middle of my driveway (move the rents' cars, of course) in a metal box. That way, in case there is an explosion, it's contained in that metal box and it would be able to put out because there's a fire extinguisher ten feet away inside my garage. But that never will happen. *knock on wood.*

[theoriganalRiD3R1967]

1 Amp is pretty close to 1100 mah was that intentional cuz you were trying decrease the charging time or you did not realize? or you just didn't want to buy another one that was the right curent?

[2wdpancar]

No pun intended .
Yeah, you're a smart charger.

By fire escape, I was referring to people who live in buildings/apartments.

[Donziikid]

Originally Posted by theoriganalRiD3R1967

1 Amp is pretty close to 1100 mah was that intentional cuz you were trying decrease the charging time or you did not realize? or you just didn't want to buy another one that was the right curent?

I own a Hobbico Quick Field Charger MKII that I use to charge all my batteries. I'm able to set the charge rate anywhere from 0.2amps - 2.0amps.

I've heard from various members of my RC Clubs that as long as I didn't exceed 1.1amp charing rate, the batteries should be able to handle the charge rate. I probably should have been a little more cautious when it came to charging and not have gone above the 0.9/0.8amp rate, but, I got greedy and went to 1.0amp. This is probably what led to the problems within the battery and initially caused a short; that would be my only plausible explaination.

[TheB1GDude]

Wow dude that sucks balls! Glad your ok!

[Donziikid]

Originally Posted by TheB1GDude

Wow dude that sucks balls! Glad your ok!

Well, if I'm not online tomorrow it's because I died of acid poisining. It was nice knowing you all!

Nah. I've had similar experiences before, but just never documented them. I thought the next time something like this happened I would document it and tell forum communities that just because you think you know all about your charging habits, doesn't mean something cannot go wrong. It's practically inevitable, things happen to batteries and they decide they want to go to battery heaven once in a while..

[Most_Wanted]

Doziikid, you should have be completely fine with charging the batteries at that rate, maybe it was just a faulty cell? That's kind of why I stick to the IB or Elite packs. Also, do you have a temp gauge? I alwasy keep an eye on my batteries and check the temp on them as they are charging.

Oh, glad you're ok and still have all your fingers and toes.



Cheers,
M_W

[theoriganalRiD3R1967]

well i have some pasnosonic AA's...there profesionally made (obviously) and the charger gives out a constant 550mah, for batteries that deliver up 2200mah, so they charge at roughly a quarter of there output current. so i'm guesing a 1/4 is a safe Ampere measure meant
But since your cells are in a pack i could be something to do with sereis or parralle concept...

[Donziikid]

Originally Posted by Most_Wanted

Doziikid, you should have be completely fine with charging the batteries at that rate, maybe it was just a faulty cell? That's kind of why I stick to the IB or Elite packs. Also, do you have a temp gauge? I alwasy keep an eye on my batteries and check the temp on them as they are charging.

Oh, glad you're ok and still have all your fingers and toes.

I charge all of my NiMH batteries in a dark corner of my room under a 120V AC fan. I've never had a battery over heat on me like that battery did. It must've been a faulty cell or a short.

I need to invest in a temperture gauge. My Dad needs one for his nitro engines and I need one for my batteries; it'd be a good investment.

[Most_Wanted]

A temp gauge definitely comes in handy. Good thing about them is they are relatively inexpensive. I use the Duratrax Flashpoint which seems to work pretty good and I think I got it for around $20 shipped off Ebay.

[Donziikid]

Originally Posted by Most_Wanted

A temp gauge definitely comes in handy. Good thing about them is they are relatively inexpensive. I use the Duratrax Flashpoint which seems to work pretty good and I think I got it for around $20 shipped off Ebay.

Thanks. I think my Dad has been looking into one of those at our LHS, just hasn't purchased one, yet. I'll get on his case about it and hope for the best.