Bending Battery

[Moderate]

Is it normal for a battery to bend during or after charging (stick type)? I noticed that someone was selling (sold) a battery that was bent, so I just wanted to clarify whether this was normal or not.

I'm only charging the battery for 45-60 minutes at the most. I first had this problem with my first battery, it would bend during charging, so I bought another battery...but it has the same problem (currently have an Intellect 8.4v 1200mAH NiMH stick type battery, original was a 1300mAH or higher of unknown or cheap brand). The lowest my charger goes is 1300mAH, could this be the problem if battery bending is abnormal?

Thanks,
Andrew

[Jimski]

bended batteries are used for powering bananas only.


1300 mah as a charge intensity is way over your battery capacity, that's wrong.
change the charger.
change the battery too.

[Moderate]

Thanks

[LUTNIT]

The lowest your charger goes is 1300mAh, wha? What kind of charger is it? If you can't afford a really nice computer controlled charger then the BB Bastard smart chargers are fairly decent for batteries of that size all the way up to 3000mAh. You can get them for cheaper off eBay than from BB Bastard but there are also some cheaper versions that look very similar but aren't nearly as good, hard to tell sometimes.

[ThunderCactus]

nothing wrong with intellect batteries, your charger is just heating up the batteries and cause the plastic to warp. Need a new charger, Pirahna digital peak charger, its like 60$ and has never caused any problems

[Moderate]

I'll check out those chargers, thanks for the help!

[JohnnyDo]

as a note just to conclude this post:

Maximum charing current for batteries shoudl be the following:

NiCad = 3C
Nimh = 1C

C is the total capacity of the battery, so if you have a 1200mAh Nimh pack, then your maximum charge current should be 1200ma, or 1.2A (A = Amp)

If you have a 3000mah NiCad battery pack, the maximum charge rate would be 9000ma or 9A.

Take note that these are maximum values and the higher the charge current, the more stress you put on the battery in the form of heat as the cells will vent gas's during charging and too much heat will literly cook your battery. This post is by no means a detailed in depth explanation of charging your battery and the pro/cons of doing so at a specific rate, but as a general guide only.

[Kos-Mos]

Don't talk about thing you don't know....please...

This 1200mAh Intellect battery can be SAFELY charged up to 2000mA. We used to charge it at 2.5-3A.

Sub-C packs can be SAFELY charged up to 4A. We used to charge them at 5-6A.

Charge rate has almost nothing to do with chemestry. Only Li-Po packs must be charged at 1C. Other packs (Ni-Cd and Ni-Mh) must be charged according to the size of the cell.

*By "we" I mean the R/C racing community.*

And for you bending battery "problem", it can happen when the shrink wraping has been done one side at the time. The side that has been done last is not yet fully shrinked, and the heat generated by the pack will cause it to try to shrink more. Also, the cells from your pack tend to extend a little when they get hotter, so both combined makes the pack bend slighly. If it comes back to normal, then it should be ok. This is the reason why most stick packs are made inside two cardboard tubes. That way they stay right and don't make people go crazy.

If you had checked the battery FAQ I took so much time to write, everything is in there... (except the bending thing....but it's not really a problem )

[DYORD]

Your battery is getting too hot!! that's why!@

[Kos-Mos]

What is it you consider "too hot"?

A battery is too hot when it reaches 120F/50C

If you pack was assembled at around 18C, then that 30 deg difference is more than enough to make the shrink work and the pack try to expand...

Fact is that if you don't have any issue when using the gun or charging, then it's nothing.

[Moderate]

Ok. Thanks