Unusual NiCad Question

[NSN]

I have ordered two 9.6 volt battery packs for my Craftsman waterproof submersible scrubber. (Great item .. I use it to keep the waterline of my pool clean).

The battery packs should be here next week and it looks as if I will not be using them until next summer.

I am sure that they will arrive in a virgin state, uncharged, with instructions to charge initially for 12 hours.

Question: Should I let them sit as is until next summer or should I charge them up and then recharge every two months. I have many items that use NiCads and I routinely charge them every two months to keep them from deteriorating when not in use for long time periods.

All suggestions appreciated.

Norm

[BinaryBillTheSailor]

Return them for a refund, and reorder next spring. Batteries, whether used or not, have a finite shelf life. Rechargeable batteries are not exempt!

BB

[Michael Daly]

Nonsense - NiCds, if properly cared for, will last for a couple of thousand charge/discharge cycles. If you lose a few cycles during the next year, big deal. I've had NiCds last for almost a decade under regular use.

However, it is best to keep the batteries in use. You want to discharge them under typical use conditions and then fully recharge them. What if you run them down in the scrubber once a month and then recharge? It should be under load, so putting the scrubber in a bucket might do - would that wear out the scrubber in some way (brushes or whatever it uses to clean with)? Another approach would be to use a resistor or some other load to discharge the batteries at a typical use rate.

Mike

[BinaryBillTheSailor]

My statement stands, and the industry agrees with it. Nicads, like all batteries, have a finite shelf life whether used or not. They start to deteriorate from the day of manufacture. Buying one a year in advance is pointless.

Meanwhile, your advice to run them dead will completely destroy them faster than almost anything I can think of.

BB

[m Ransley]

New Nicads should be left as is till you use them . They are stored better discharged as they will come, and never run them dead. When a motor just slows , the datteries should be considered dead. Not when it stops. NiCads are discharged at 1.2v per cell , further discharging can reverse a cell and shortens life. Also dont overcharge them, a peak charger should be used, When voltage decreases or heat increases they are fully charged. Ive never got Thousands of charges on nicads If lucky you get 1000. But used carefully I have 18 yr old Makita packs.

[HRL]

Nicads stored uncharged can be kept indefinitely. When stored charged they self discharge at about one or two percent a day. I expect an average life is about 5 years but I have some that have lasted over 30 years. Some of that time was uncharged.

[m Ransley]

Who was making and using nicads 30+ yrs ago thats 1974. I didnt think Makita came out till early 80

[Michael Daly]

Nowhere did I say run them dead. If the scrubber is designed for NiCd, it'll quit when the NiCd is discharged to an appropriate level.

Mike

[Robert Bonomi]

Edmund Scientific was selling *surplus* ones circa 1966.

[Andy Asberry]

Read what Red says.

[HRL]

I have a Sonotone D Cell dated: 3-27-67 that is still working:

NICAD batteries have been around for a long time. Not certain just when they were first developed. At least by the 1920s.

[m Ransley]

Well Mike Daley I dont know of any equipment that just quits on its own before ruining a battery, or overdischarging it. Camcorders yes, But tool makers make most of their money selling replacement batteries to people that ruin them out of ignorance. When it starts to slow down it is dead. But you are still able to run them till the equipment has drained them completely., There is no saftey on tools I have for low voltage.

[clifto]

Leave them uncharged until you're ready to put them in service.

Think about it; they are made to sit on the shelf a long time without charging until they reach the customer, who somehow gets good life out of them after that.

Nicads do NOT like being stored in the charged state.