Anthona wrote:
I just purchased online from home depot an edger/trimmer...In the
specifications it said electric, nothing mentioned about batteries.
and i thought that was what i getting. It turned out it was cordless
with 18v ni-cad battery. Now from past experience, i have had bad luck
with those batteries...mostly through my ignorance of different type
of batteries..Recently i learned that Lithium batteries were the
better choice, if i was going for cordless. I went back to the site
and sure enough, the heading of the sale did say cordless. Now can
someone tell me how to maintain these batteries when not in use?
Obviously here in the new england area i won't be using it all year.
The manual says nothing about that.

NiCads last for far more discharge cycles than other batteries and are
more tolerant to high discharge currents and overcharging.

The problem is crystal growth. It reduces capacity and eventually
shorts the cell. Leaving the cell on a charger causes the fastest
growth. They also grow when a cell sits.

Once a month, exercising a cell by discharging it down to 1 V will
dissolve crystals and increase life expectancy by about ten times. If
it has been more than 3 months, slowly discharging from 1 V down to 0.6
V may help.

Having 15 cells in a sealed battery pack complicates maintenance.

On Apr 1, 5:50*pm, J Burns wrote:
Anthona wrote:
I just purchased online from home depot an edger/trimmer...In the
specifications it said electric, *nothing mentioned about batteries.
and i thought that was what i getting. It turned out it was cordless
with 18v ni-cad battery. Now from past experience, i have had bad luck
with those batteries...mostly through my ignorance of different type
of batteries..Recently i learned that Lithium batteries were the
better choice, if i was going for cordless. I went back to the site
and sure enough, the heading of the sale did say cordless. Now can
someone tell me how to maintain these batteries when not in use?
Obviously here in the new england area i won't be using it all year.
The *manual says nothing about that.

NiCads last for far more discharge cycles than other batteries and are
more tolerant to high discharge currents and overcharging.

The problem is crystal growth. *It reduces capacity and eventually
shorts the cell. *Leaving the cell on a charger causes the fastest
growth. *They also grow when a cell sits.

Once a month, exercising a cell by discharging it down to 1 V will
dissolve crystals and increase life expectancy by about ten times. *If
it has been more than 3 months, slowly discharging from 1 V down to 0.6
V may help.

Having 15 cells in a sealed battery pack complicates maintenance.

Re "dead" NiCds. There is a kill or cure it solution. As someone else
said the problem is with whiskers of metallic cadmium inside the
cells. The answer MIGHT be to "flash 2 the dud battery across an
automobile battery. (ie a momentary connection) to blast the whiskers
away. Sometimes it works (for a while anyway). You need to wrap the
NiCd in a bundle of rag, they can burst open & ideally do it with a
long wire (so you can be well clear). Afterwards try to charge as
normal.

On Apr 1, 11:50*am, J Burns wrote:
Anthona wrote:
I just purchased online from home depot an edger/trimmer...In the
specifications it said electric, *nothing mentioned about batteries.
and i thought that was what i getting. It turned out it was cordless
with 18v ni-cad battery. Now from past experience, i have had bad luck
with those batteries...mostly through my ignorance of different type
of batteries..Recently i learned that Lithium batteries were the
better choice, if i was going for cordless. I went back to the site
and sure enough, the heading of the sale did say cordless. Now can
someone tell me how to maintain these batteries when not in use?
Obviously here in the new england area i won't be using it all year.
The *manual says nothing about that.

NiCads last for far more discharge cycles than other batteries and are
more tolerant to high discharge currents and overcharging.

The problem is crystal growth. *It reduces capacity and eventually
shorts the cell. *Leaving the cell on a charger causes the fastest
growth. *They also grow when a cell sits.

Once a month, exercising a cell by discharging it down to 1 V will
dissolve crystals and increase life expectancy by about ten times. *If
it has been more than 3 months, slowly discharging from 1 V down to 0.6
V may help.

Having 15 cells in a sealed battery pack complicates maintenance.

Drain a Nicad pack and you can easily reverse a cells polarity and
ruin the whole pack, 1.2v is considered discharged, I wonder if 1v is
bad for a single cell V. I have 20 yr old packs that still get me some
use and I never drain them past when the tool slows down or excersise
them.

On Thu, 1 Apr 2010 12:29:13 -0700 (PDT), ransley
wrote:

On Apr 1, 11:50*am, J Burns wrote:
Anthona wrote:
I just purchased online from home depot an edger/trimmer...In the
specifications it said electric, *nothing mentioned about batteries.
and i thought that was what i getting. It turned out it was cordless
with 18v ni-cad battery. Now from past experience, i have had bad luck
with those batteries...mostly through my ignorance of different type
of batteries..Recently i learned that Lithium batteries were the
better choice, if i was going for cordless. I went back to the site
and sure enough, the heading of the sale did say cordless. Now can
someone tell me how to maintain these batteries when not in use?
Obviously here in the new england area i won't be using it all year.
The *manual says nothing about that.

NiCads last for far more discharge cycles than other batteries and are
more tolerant to high discharge currents and overcharging.

The problem is crystal growth. *It reduces capacity and eventually
shorts the cell. *Leaving the cell on a charger causes the fastest
growth. *They also grow when a cell sits.

Once a month, exercising a cell by discharging it down to 1 V will
dissolve crystals and increase life expectancy by about ten times. *If
it has been more than 3 months, slowly discharging from 1 V down to 0.6
V may help.

Having 15 cells in a sealed battery pack complicates maintenance.

Drain a Nicad pack and you can easily reverse a cells polarity and
ruin the whole pack, 1.2v is considered discharged, I wonder if 1v is
bad for a single cell V. I have 20 yr old packs that still get me some
use and I never drain them past when the tool slows down or excersise
them.

You can safely discharge a single cell NiCd down to zero. The problem is
reverse charging a cell by discharging a multi-cell battery pack too far. Cell
reversal is cause by mismatched capacity, so with perfectly matched cells one
could discharge a multi-cell battery to zero safely but cells are never
perfectly matched. It's generally safe to discharge a multi-cell battery down
to about 1.1V or even 1.0V per cell. Limiting discharge to 1.2V/cell throws
away a significant fraction of the useful capacity.

"J Burns" wrote in message
...
Anthona wrote:
I just purchased online from home depot an edger/trimmer...In the
specifications it said electric, nothing mentioned about batteries.
and i thought that was what i getting. It turned out it was cordless
with 18v ni-cad battery. Now from past experience, i have had bad luck
with those batteries...mostly through my ignorance of different type
of batteries..Recently i learned that Lithium batteries were the
better choice, if i was going for cordless. I went back to the site
and sure enough, the heading of the sale did say cordless. Now can
someone tell me how to maintain these batteries when not in use?
Obviously here in the new england area i won't be using it all year.
The manual says nothing about that.

NiCads last for far more discharge cycles than other batteries and are
more tolerant to high discharge currents and overcharging.

The problem is crystal growth. It reduces capacity and eventually
shorts the cell. Leaving the cell on a charger causes the fastest
growth. They also grow when a cell sits.

Once a month, exercising a cell by discharging it down to 1 V will
dissolve crystals and increase life expectancy by about ten times. If
it has been more than 3 months, slowly discharging from 1 V down to 0.6
V may help.

Having 15 cells in a sealed battery pack complicates maintenance.

That many cells, packed in a ring, are designed to fail because the internal
cells can't dissipate the heat from charging as well as the outer ones and
eventually fail quite prematurely. I have taken apart six Firestorm B&D
battery packs that were carefully charged on a fast charger that dropped
down to a trickle charge once the batteries were full. In each and every
one, the center (tower)cells in the cluster were bad. And that was only a
9.6V drill.

Fortunately, it was very easy to cut the plastic battery case open, and
instead of replacing the bad NiCads, (which are almost always tacked and not
soldered together and I find a bitch to work with) I just mounted a holder
made out of plastic and velcro straps for a 12V SLA gel cell battery and use
them. You can get an SLA 12V 3AH battery pack that costs about $9 compared
to B&D's insane price of $45 which is more than I paid for the new drill and
two packs in a case with a fast charger.

I was able to preserve the locking mechanism on the original battery case so
I could switch out my modified packs just as easily as I could the original
NiCad. I also wired up the charger to a gel cell float charger and a DPDT
switch so I could charge either type of battery.

It's almost as good as the original, it's much cheaper and much more
powerful. The only issue is that it's a little more unwieldy than the
original NiCad pack in really tight spaces. But it's always ready (gel cells
hold their charge for a year) and it's always got plenty of power.

--
Bobby G.