Having trouble with C-9000 and AAA cells

[Mr Happy]

I'm just for the first time trying to put AAA cells in my C-9000 and I'm having all sorts of trouble. It seems that the contact spring for the negative end of the cell is not positioned in the middle of the cell, but right at the bottom edge, so it rests on the overwrap of the plastic insulation instead of the metal. As a result, the cells don't make electrical contact and the charger doesn't recognize they are inserted.

When I look closely with a magnifier it just seems like the contact design is wrong. Has anyone else experienced the same trouble?

 

[not2bright]

Mr Happy, my C9000 (both the pre-order early version and firmware update replacement unit) have no problems with eneloop, hybrid, and regular Sanyo 900 mAh AAAs.

I know that really doesn't help, but it may prove to be isolated to your charger.

 

[Mr Happy]

I've just examined some Rayovac Hybrid AAA cells and on those the outer cover stops short at the negative end and doesn't wrap around it. So I imagine those may work without trouble. It seems like the cover should wrap around the base of cells though, to guard against possible shorts in a metal flashlight tube.

 

[whippoorwill]

Put the negative end in first and slide it down to make contact. It will then 'snap' into the top. Putting them in both ends at the same time will not make the necessary contacts. It is a little tricky until you get the hang of it.

 

[Anders]

I also have problems with AAA cells in c-9000 despite that I always put the negative end in first and slide it down to make contact.

Sometimes they pop out so I have to put them in again, some of my AAA cells have a inward bend in minus end, I don't know if it is MAHA C808M or C-9000 that is responsible of that cause C808M is also very tight but the cells never pop out in C808M.


Anders

 

[tpchan]

I too am having trouble with certain brands of AAA rechargeable cells. I've called Maha for an answer and their reply is that some brands of cells are too short and don't fit the charger correctly. Yes, Eneloop AAA's fit just fine and recharge correctly but my older Maha (Blue & Orange) nimh AAA's don't fit correctly and are not recognized by the C-9000. Maha advised me to just use my older MH-C204F charger on those cells. Yes the AAA's that don't work keep "popping" out when you try to put them in the C-9000. Even holding the cell down by finger pressure is not enough to get them recognized. Yes I'm inserting the AAA's negative end first as it clearly states in the (very short) instructions of the C-9000.

 

[whippoorwill]

Luckily, this has not been a problem for me. I use eneloops, ROV hybrids, Duracell 1000 MaH and 800 MaH LSD. I have not had any experience with other cells. The above must all be long enough to work.

 

[Mr Happy]

I took my troublesome cells and, with sharp scissors, carefully snipped away the plastic overwrap around the base to expose the whole area of the negative plate. The plastic was getting all torn up by the charger anyway. They now work successfully.

This is in my opinion a design flaw with the C-9000. The negative contact spring for AAA's in the battery compartment is the wrong shape and in the wrong position to make reliable contact with any cells that don't have a large flat negative end with no overlapping insulation. Cells that have a stepped back edge, or a grooved bump, or overlapping insulation at the negative end are going to give trouble.