Crackling noise from NiHM after charging?

[jcw122]

Hi,

I just bought a new charger and charged a battery that has not been charged in at least a year. It is a Sanyo 2700. It is now making a very faint but distinct crackling noise. It is warm, but not hot to the touch. Is this bad, what does this mean? Thanks.

-Jon

 

[rizky_p]

Are you reffering to the battery or the charger? pulse charger making a crackling noise while charging is normal i think.

the last time i heard a faint cracking noise from battery when i accidently short several sanyo 2700, it was hot though unlike yours. I dont think battery should making any noise.

 

[jcw122]

It came from the battery once it was done charging. The noise subsided after about 10 minutes though.

 

[NonSenCe]

one of my cheap nimh batteries started to hiss and sizzle and crackle on the charger .. it was too hot to hold.. so i chucked it out and into trashcan as it cooled down. couldnt trust it anymore.

they are supposed to be silent. so i think it was boiling inside and there was a leak in casing as the noise was loud. all other i bought (15) have worked fine for 2 months now.

(they are green colored Tronic-brand 2500mah from Lidl store which is a originaly a german cheap store)

 

[Illum]

where is the crackling sound concentrated at, near the top? middle? everywhere?
NiMHs have been known to vent hydrogen during cell cycling...perhaps it was just passing gas with its pants on? :thinking:

Something tells me what your hearing is the plastic wrap stretching itself out and tearing tiny fissures on the fabricated surface outside the cell canister...its a sign that the batteries were way hotter than they were designed for, when they begin to cool off the plastic went back to its rigidness.

It could be because of

• Improper charger
  • Too high of charge current
  • Overcharging cells
• Nearing end of battery life
• Battery internal issues

Check if other cells are having the same issues:

• If so, replace charger
• If not, recycle battery

 

[travelinman]

What's the charger?

 

[rizky_p]

Something tells me what your hearing is the plastic wrap stretching itself out and tearing tiny fissures on the fabricated surface outside the cell canister...its a sign that the batteries were way hotter than they were designed for, when they begin to cool off the plastic went back to its rigidness.

@Illum: never thought of that.

A battery with higher internal resistance will be hotter in the charger with the same current applied.

 

[jcw122]

The charger is the La Cross BC-900. I'm refreshing all of my Sanyo 2700s now and I haven't had any issues thus far, maybe it was a one off thing.

 

[Illum]

@Illum: never thought of that.

A battery with higher internal resistance will be hotter in the charger with the same current applied.

I fried a couple elite 1700 batteries using an improper charger... the plastic at both ends started shrinking towards the middle and for a bit it sounded like tearing Styrofoam

 

[SilverFox]

Hello Jon,

Most likely your cell was venting due to overcharging. A NiMh cell that sits for a year may not provide the charge a clear end of charge signal. Without that signal, the charger just keeps charging.

This often occurs at lower charge rates.

Your cell is damaged, but you may be able to get some use from it. I would not suggest using that cell with others in a multi cell application, but it may work for a while in a single cell light.

Tom

 

[jcw122]

Hello Jon,

Most likely your cell was venting due to overcharging. A NiMh cell that sits for a year may not provide the charge a clear end of charge signal. Without that signal, the charger just keeps charging.

This often occurs at lower charge rates.

Your cell is damaged, but you may be able to get some use from it. I would not suggest using that cell with others in a multi cell application, but it may work for a while in a single cell light.

Tom

Yeah I was using a charge rate of 500 mA. Thanks for the info.

What could happen if I use it?

 

[SilverFox]

Hello Jon,

It will start off with just a little less capacity than your other cells, then it will gradually loose more and more capacity with each cycle. In addition, the self discharge rate will increase.

When you use multiple cells, you want them all to be matched. If you use this cell with others, it will empty first and runs a chance of being reversed charged during the discharge. This will further damage the cell.

Tom

 

[jcw122]

Hello Jon,

It will start off with just a little less capacity than your other cells, then it will gradually loose more and more capacity with each cycle. In addition, the self discharge rate will increase.

When you use multiple cells, you want them all to be matched. If you use this cell with others, it will empty first and runs a chance of being reversed charged during the discharge. This will further damage the cell.

Tom

OK, thanks a bunch, Tom.