Charger problem?

[todd92371]

Hello,
I just picked up a RayoVac PS3 charger and some eneloop batteries. Charged 4 AA batts last night and the red light went off. I moved the batts to a different slot out of curiosity and the red light came on and stayed on for a while charging them. I'm confused? The red light went off and finished the charge. Why are they charging again in a different slot?

Thanks!!!!
todd

 

[SilverFox]

Hello Todd,

That is a good way to ruin your new cells...

When a cell is put into the slot, the charger thinks that it is a discharged cell and begins to start the charge process again. Depending on the type of termination the charger uses, you can end up overcharging your cells by doing that. Many chargers ignore termination signals for the first part of the charge to avoid under charging the cells.

Eneloop cells are particularly sensitive to over charging, so it is best to avoid doing that again.

Tom

 

[TakeTheActive]

...I just picked up a RayoVac PS3 charger and some eneloop batteries...

To get the longest life out of your new Eneloops, get a better charger than that ''Old Technology' PS3: Rayovac PS3: Multiple Versions? Parallel Charging? Specs?

The Maha MH-C9000 and the La Crosse BC-900 have many nice features: TTA's NiMH/NiCD Battery Charger Specifications Thread

You can also learn a great deal about Rechargeable Batteries in general by reading the LINKs available through my Sig Line LINK.

Grab a beverage and have fun!

 

[todd92371]

This is confusing. I thought a "smart" charger would know when enough is enough?

todd

Thank you by the way.

 

[Mr Happy]

This is confusing. I thought a "smart" charger would know when enough is enough?

The designers of "smart" chargers do not expect "dumb" users to try charging fully charged cells

 

[todd92371]

Thanks Mr. Happy. I appreciate that. I'm also glad you are so happy.

I found this on a forum in refernence to how the charger works
When an unknown cell is inserted into the PS3, the charger first starts off with a trickle current (800mA peak current at 10% duty cycle, or an average current of 80mA). Based on the voltage profile of this cell, the PS3 can determine whether this is an alkaline cell, or a NiMH cell. After two minutes, the duty cycle is increased to 60%, so the average current is now around 480mA. For a NiMH cell, charging will continue until a negative dV/dt is detected, in which case it switches back to trickle current again. But for an alkaline cell, charging current will gradually decrease with higher terminal voltage until it reached 1.65V.

I also put the cells into a different channel because I heard this unit sometimes has problems with the red light going off. It seems to me that a smart charger should know when a battery is full. That is the whole point- right.

todd

 

[Mr Happy]

I also put the cells into a different channel because I heard this unit sometimes has problems with the red light going off. It seems to me that a smart charger should know when a battery is full. That is the whole point- right.

See, there are two different cases:
1. Start charging an empty battery and figure out when to stop charging.
2. Detect that an already full battery is full.

Case 1 is what smart chargers do and they are quite good at it. Case 2 is technically much harder to achieve, and while the charger will figure it out eventually the battery is going to get overcharged a bit in the mean time.

 

[todd92371]

That is good info.
So, what if you use a battery one night and it's not fully discharged (used half) per se. Is it not a good idea to recharge it that night after use? Wait until it is fully depleted and then put in new batteries? If you are running at night you want fresh batts to start a run with. See what I'm getting at?

THANKS,
todd

 

[TakeTheActive]

...I found this on a forum in refernence to how the charger works
When an unknown cell is inserted into the PS3, the charger first starts off with a trickle current (800mA peak current at 10% duty cycle, or an average current of 80mA). Based on the voltage profile of this cell, the PS3 can determine whether this is an alkaline cell, or a NiMH cell. After two minutes, the duty cycle is increased to 60%, so the average current is now around 480mA. For a NiMH cell, charging will continue until a negative dV/dt is detected, in which case it switches back to trickle current again. But for an alkaline cell, charging current will gradually decrease with higher terminal voltage until it reached 1.65V.

Please post the LINK to this information. I'd like to see what else that forum has to read on rechargeable batteries.

After starting out with the 'Black & White' GE NiCDs in the late 1980s, I tried the Rayovac Renewals. My first NiMHs were Rayovac 1300mAhs. Rayovac-wise, I have 3 PS1s (2 gray, 1 black), a PS3 and a PS23-B. The only one that I 'might' put a LSD into is the PS23-B. I also have a Maha MH-C9000 and a La Crosse BC-900 for my 'good' cells.

Thanks!

P.S. Does anyone know offhand the rated capacities of the old GE NiCD AAA, AA, C, D and 9V? I lost my last D a year or so ago, but I still have 3 Cs in service - over 20 years! Used them in my son's Speak and Spell.

 

[Mr Happy]

That is good info.
So, what if you use a battery one night and it's not fully discharged (used half) per se. Is it not a good idea to recharge it that night after use? Wait until it is fully depleted and then put in new batteries? If you are running at night you want fresh batts to start a run with. See what I'm getting at?

No, half empty should be fine. It is only the attempt to charge fully charged batteries that is inadvisable.

 

[TakeTheActive]

Please post the LINK to this information. I'd like to see what else that forum has to read on rechargeable batteries...

According to GOOGLE, this information appears to have originated with NLee the Engineer on Amazon and then propagated across many (Amazon-related?) shopping sites. I didn't find it on any forum.