Recharging NiCad batteries

[coinhunter1952]

I have a Musketeer colt with a rechargable Nicad system..how long do I keep the charger plugged in for a full charge? Thanks.

 

[D&P-OR]

coinhunter1952-----Overnight is PLENTY sufficient.--Whether they be Nicad's or NMHyd's-I NEVER keep mine on the charger longer than that.--The "book" says you can keep the charger on them pretty much indefinitely (in some cases anyway).--But you can damage (fry) your batteries by doing that on a consistant basis & long term basis.--I've "PROOVED" that a couple of times & with different types of batteries.-------Del

 

[grumpyolman]

Coinhunter...There has been a long term debate how to treat Ni-cads and NiMhs. It certainly didn't begin in the MD market. Ham radio with the advent of the 2-meter hand held radios have needed reliable rechargeable batteries for years. I've read a gazillion tech reports from amateur radio folks to electrical engineers and if you look long enough you will get a gazillion different pieces of advice to follow. After all the HAM stuff and other applications I think there are two things that are pretty much believable. Ni-cads do develop a memory. If you top them off,. like after a 25% drain from usage, repeatedly they will eventually have a life about 25% of what their life could be. NimHs don't have that problem and it's to do with the chemistry of the cell. I dont' know the chemistry part of it.
Charging time is something else all together. That is dependent, to a certain degree, about how sophisticated the charger is, what the voltage is, and what the capacity of the battery is. I have a Ma-Ha charger, about $100, that was designed primarily for ham use. It'll charge a lot of different battery types and configurations. One has to set a switch to tell the charger if you are charging a Ni-cad, NiMh, lithium. lithium ion, or lithium polymer. The computer inside the charger then check the condition of the battery and applies the correct charge for the right amount of time then continues to trickle charge , or not depending on if it's needed for that kind of battery, One can do a controlled discharge and the unit measures the Mah taken out of the battery and that conditions it, and then puts a charge back in. If you have a 1400 mah battery and the unit can only put in 800 mah, after conditioning, that's and indication that battery has pretty much reached it useful life. I have 'conditioned' batteries with the charger that others have thought were dead, and they gave me lots of charges to use as a back-up battery. The thing even has a sensor to place on the side of the battery to measure the heat of the battery during charge. It's a safety thing. Lithium polymer batteries can explode during charge if not done correctly. If you see yourself as having a need for charging lots of batteries, investigate getting a technically sophisticated charger. It'll pay for itself over the years. Jim

 

[Captain Kirk]

In the "olden days" I used to design chargers for Ni Cad batteries. As has been mentioned in other posts Ni Cad suffer from the "voltage depression" effect (sometimes referred to as "memory").
* In order to reduce the depression effects it is best to exhaust the charge on the Ni Cads before recharging.
* How long you can leave them on the charger depends upon the design of the charger.
* Some charger designs are sophisticated and extend the life on the batteries while others are very basic and can damage batteries quickly. The good design uses multi-stage charging ending with a "trickle charge" to "top off" without damaging the battery.
* For typical chargers the battery will remain relatively cool (unless the charging rate is excessive) until the charging has been completed. After the charging has been completed, then the temperature will rise dramatically. If the battery is getting hot, then either the charging rate is too high or the charging has been completed.

Hope this helps. HH,
Glenn

 

[D&P-OR]

Guys---When I spoke of chargeing batteries-I believe the question was regarding the Minelab battery pack & charger (at least that was the way I took it).---In my experience with both Minelab & White's rechargeable battery packs & their house chargers (and I have had considerable use with these)--you need to be careful about consistant, long term charge of these packs.----Your points are well taken but a lot of us don't have sophisticated chargers (though we probably should have).-------Del

 

[grumpyolman]

The information given about how batteries react to given charges applies to any battery of that type. Minelab or White's rechargeable packs are no different than the HAM battery packs, radio control battery packs, except for the shape and how they electrically connect to the MDer. Certainly a 'good' charger is not the first thing one should get as an acessory, but ruin one Ni-Cad pack by overcharging, which the simple wall detectors can do, and you'd have paid for the 'smart' charger. HH Jim

 

[Captain Kirk]

Jim,

I appreciate your comments. I am sorry that I did not make myself clear. I did not mean to suggest that anyone would need a better charger for the Minelab batteries. My comments only related to charging Ni Cad batteries with their special issues. You are certainly correct that a cheap charger is not a bargain.

The Minelab rechargeable batteries are NiMH and do not have the annoying problems of Ni Cad batteries.

HH,
Glenn

 

[grumpyolman]

I purchased a used Excalibur on this forum and it had NiCads in it. Not knowing how they had been treated, I ordered a set of NiMh from one of the battery pack distributors and replaced the NiCads. If I remember correctly, some of the SEs came with NiCads in the earlier days and since have been changed to the NiMhs. NiMh is the better choice for sure. Jim