How can I tell if my charger is "smart"? it's a Pentax V-3969

[fishwatcher]

I have an old Pentax "Power Charger", that charges ni-Cd and NiMH (there is a switch that chooses between these two options). It is capable of charging AA, AAA, and 9V's.

It can charge 4 batteries, and has 2 led's, when charging, that go from red to green when charging is complete. If I put only 1 cell in, one of the charging LED's will still light up.

Question is:

How can I tell if my charger is "smart" or not? How can I tell if I have a 4 channel charger, or a 2 channel charger?

On the back, the specs read:

Model V-3969
Input: 120V AC 60Hz 6W
Output: AA-4x (1.4V DC 210mA)
AAA-4x (1.4V DC 80mA)
9V cell-2x (9.0V DC 15mA)

Charging time:
NiCd AA/AAA: 4 hours
NiMH AA/AAA; 7 hours
NiCd/N-Mh 9V: 10 - 15 hours by manual

Does anybody else use this charger? Is it a good one for modern NiMH AA rechargeables?

Thx!

 

[Mr Happy]

I'd say it's a four channel timed charger.

The reason I think it has four channels is because of this line in the specs:

Output: AA-4x (1.4V DC 210mA)

The 1.4 V is just enough to charge a single cell.

This would also indicate why it seems to be a timed charger. The charging current of 210 mA is low enough for a trickle charge without overheating the cell, and the 1.4 V will produce a natural reduction in charging current as the charge completes since NiMH cells reach about 1.4 V when fully charged.

The term "smart" is something of a marketing cliche I think. All chargers that are going to do a fast charge of NiMH cells (4 hours or less) need to be smart. It's the only way they can detect the end of charge properly and avoid overheating the cells. On the other hand, low rate chargers don't need to have the same smarts as there is less risk of damage from overcharging.

The charger is probably fine if you don't mind waiting overnight for a charge to finish. It's possible it might not put the maximum charge into modern higher capacity cells, but I don't know enough about it to say.

 

[shakeylegs]

Ask it to do your tax return.
If it can do that, it's smart

 

[fishwatcher]

Great replies, both of them.

Thanks. I've picked up the Costco Eneloop pack now, so will keep this Pentax charger, as a back-up.

 

[65535]

As long as the voltage isn't over 1.5 volts, and the current is under the capacity of the cell you can charge with it. Smart chargers actually rely on data feedback from the cell to terminate the charge process, IMHO CC/CV charging is the best, charge is terminated when it starts to trickle.

 

[fishwatcher]

65535:

What is CC/CV charging?

:thinking:

Thx.