flyerdave

My Feedback: (212)

I have a 50cc aeroworks ultimate that I bought already set up with redundant switches running to a single A123 2300ma battery. I just brought the plane in after flying yesterday to clean it and charge the battery. I hooked the cellpro multi-4 up to the charge port and was charging at 4.00 amps not seeing any problems, all of a sudden, the charger beeped and read (incorrect cell count) and the smoke was just rolling. I snatched the charge cord out of the charge port. I found what I think was the problem, it looked like the charge wire had possibly shorted because of a break in the wire sheathing. Anyway it melted some of the internal parts of the switch and I disconnected the battery from both switches and the balance tap. Connected the cell pro straight to the battery and finished the charge just fine.The battery has dual deans connectors and the balance tap. The switch had been modified so it could'nt backfeed into the receiver. My question is could the short have damaged the receiver in any way and if there had been any damage to the battery, would it have finished the charge and balanced perfectly?
Thanks for the help.

TheWoodCrafter

My Feedback: (1)

I don't see how it could have hurt the RX.

The battery may or may not have been damaged.
It seems to work but it may have shortened its life.
I would keep an eye on it and maybe measure its capacity.

flyerdave

My Feedback: (212)

Turns out that my problem was the switch,so thanks for the help.I do know that I will never charge these A123 batteries unattended. Thanks

rmh

The batteries won't self destruct - but the power output possible is such that shorting them can burn up wirings quite easily.
I won't use anything but A123 for rx packs -

nonstoprc

My Feedback: (90)

I once had the experience of short-circuit a 2-cell A123 pack for a brief moment. No harm was done to the battery.

pilotpete2

I sure hope that "brief" short didn't occur in one of your pockets[X(] Been there, done that with an AA Nicd
They're pretty much bullet proof, but fool proof? If there's a way, I'll find it[&:]
Pete

BarracudaHockey

My Feedback: (11)

Saw someone coming home from the range had a short (nystarter) in his pocket that cooked of a 9mm once. Talk about hippity hop.

Mikecam

You really shouldn't charge at any more then 3 amps max thru the switches. Most likely that was your problem, especially if your switches were not at least 22 gauge. If less then 22 gauge then charge at max 2 amps.

I like electrodynamics switches.

http://www.electrodynam.com/rc/usw/index.shtml

I love my A123/Multi4 setup, balance charging thru the switch is as simple as it gets.

I also agree that your battery should be fine. Just check to make sure the cells stay in balance the next couple of charges.

pilotpete2

+1 Mike!
Before I got the Multi4, I was using a Cellpro 4S which is fixed at 4A for A123's. I had a contact get so hot on the male pins that plugs into the charge jack, that it distorted the plastic housing for the contacts. The charge cable I was using was 20awg, but a little resistance on the contacts made 4A too much. I run the Multi4 at 3A with no problems. Did I say I like the Multi4[8D]
Pete

Nogyro

My Feedback: (10)

Be sure to keep an eye on your charge lead where you plug it into your switch. I was using the Cellpro 4s as well for several years and the 4 amp charge rate will eventually melt the insulation on the wire right at the connector. The std. servo ends just can't take the 4 amp charging rate and over time this will happen. I recently got the multi 4 and set the charge rate to 3 amp. The charge connector doesn't get near as warm at that rate.

P-40 DRIVER

Your battery maybe able to handle a 4 amp charge, but your switch/ wiring can't, I would go to a 1C charge if it was me. I would also change everything going back to your battery, if anything got hot, your have developed a weak spot and it will continue to degrade untill failure including the battery connector. Those connectors are only rated for three amps at full duty cycle thats assuming everything is perfect.

rexbirk

The battery should be fine. It can put out far more than the switch and wiring can tolerate! Those A123 batteries are amazing. I usually charge mine at 1 amp to 1.5 amp.

Capt Cash

My Feedback: (1)

Yep, A123s are where it's at! I get mine with the single wire feed from Hangtimehobbies and charge through a standard HD switch with the FMA Multi4 charger. They are without a doubt the best batteries I've ever owned, consistent and reliable. I balance charge every single time and monitor my usage vs. what mAh goes back in so I can catch any potential problems early on.

Normally I charge at 1.5A at home since time is not an issue, but sometimes when a field charge is necessary I use a max of 3.0A.

pilotpete2

++++1
Pete