VHF Battery Pack Rebuild
'Lo All,
I recently had an Apelco VHF 501 handheld radio 600 mAh 10.8 V battery pack
rebuilt. We have a local shop that can replace Nickel Cadmium (NiCd) cells
for less than I have found anywhere else, but NiCd cells have a major
drawback. They "remember" the discharge from one recharging to the next.
Ultimately, they end up storing only a small charge and quickly "go dead".
I found a company on the internet - Primecell - that replaces NiCd cells
with Nickel Metal Hydride (NiMH) cells in some applications - this radio
battery pack, for example. NiMH cells do not have a "memory". Normally,
NiCd and NiMH require different chargers because they have different
voltages across each cell. Primecell installs circuitry in the battery pack
so that the same (original) charger can be used. I had some problem with
their website as some of the pages were "Forbidden", but I rummaged around
and finally got answers to my questions.
I sent the battery pack to them for rebuild.
I now have a 1200 mAh battery pack that uses the original Apelco charger.
(Yes, it is now a 1200 mAh pack!) The jury is still out on how long the
battery pack will ultimately last, but it charged up on the Apelco charger
and has worked for the last two weeks whenever I needed it.
The local price for a NiCd cell rebuild was about $28.00 + tax, the price
for the NiMH rebuild was $34.50 + $5.00 shipping = $39.50.
Primecell rebuilds almost any kind of battery pack and has a very extensive
list of applications on their website at primecell.com. Not all are NiCd to
NiMH conversions. They are not (very) good at communications, as I sent
several emails to ascertain the status and shipping date, and did not
receive any replies. The battery pack was; however, shipped very promptly,
and I received the battery pack about a week and a half after sending it.
They accept PayPal, so it was easy to set up the transaction. When the
battery pack was rebuilt and ready to ship, they sent a PayPal invoice.
They shipped the battery pack upon receipt of payment.
No connections, but, so far, anyway, a happy customer.
Take care and be safe.
Wayne
M/V Celestial
Albin43 Sundeck
Wayne,
A few words of caution...
There are a few other subtle, but real, differences between NiCd and NiMH
cells. Basically you should not use a charger for NiMH that hasn't been
designed for that cell chemistry. Either the charger must be restricted to
a very slow charge rate or the cell/charger needs to be aware of the ambient
temperature and the temp inside the battery pack. NiMH cells get real
unhappy when they are charged too hot or even too cold.
The other thing is overcharge. NiCd does not worry about overcharging unless
it gets to the point of creating enough heat to out-gas the hydrogen by
product, breaking the seal on the top of the cell and seriously restricting
it's ability to take a charge from that point onward. NiMH cells cannot
tolerate any overcharging, period. You will be able to tell if you existing
charger is overcharging by the very short service life you get out of the
new cells. When you take the pack out of the charger the it should not be
warm to the touch at all.
Good luck,
Jim Fuller
"Miss Em"
Santa Cruz, CA
... I found a company on the internet - Primecell - that replaces NiCd
cells
with Nickel Metal Hydride (NiMH) cells in some applications - this radio
battery pack, for example. NiMH cells do not have a "memory". Normally,
NiCd and NiMH require different chargers because they have different
voltages across each cell. ...
Wayne, correct. I mentioned PrimeCell here a few months back, as they have
rebuilt battery packs for many of my marine, aviation and amateur handheld
radios. Good folks. And for those not into PayPal, they're happy to accept
credit cards.
Bob Peterson
47' Lien Hwa CMY
"Lopaka Nane"
San Francisco
-----Original Message-----
From: Albin43SDtr
Sent: Monday, May 03, 2004 1:17 PM
To: trawlers-and-trawlering@lists.samurai.com
Subject: T&T: VHF Battery Pack Rebuild
'Lo All,
I recently had an Apelco VHF 501 handheld radio 600 mAh 10.8 V battery pack
rebuilt.
I found a company on the internet - Primecell - that replaces NiCd cells
with Nickel Metal Hydride (NiMH) cells in some applications - this radio
battery pack, for example. NiMH cells do not have a "memory". Normally, NiCd
and NiMH require different chargers because they have different voltages
across each cell. Primecell installs circuitry in the battery pack so that
the same (original) charger can be used. I had some problem with their
website as some of the pages were "Forbidden", but I rummaged around and
finally got answers to my questions.
We have a local shop that can replace Nickel Cadmium (NiCd) cells for
less than I have found anywhere else, but NiCd cells have a major drawback.
They "remember" the discharge from one recharging to the next. Ultimately,
they end up storing only a small charge and quickly "go dead".<<<<
For some years I've been building battery packs for bicycle lighting
systems, and during my research I found that there's a lot of dodgy
information floating around about NiCd and NiMH rechargeable batteries. Most
particularly, except in some very specialised aerospace applications, NiCd
"memory" is a myth. Also the common advice that one should "fully discharge"
NiCD batteries to "avoid memory" is dangerously misleading.
What kills NiCd batteries is over-charging AND over-discharging.
Overcharging occurs when a battery charger is used which does not
incorporate the necessary "smart" electronics to detect when the battery is
full. Many rechargeable battery products are supplied with such "dumb"
chargers as a result of penny-pinching by the manufacturers.
Over-discharging occurs where the battery is discharged down to less than
about 1 volt per cell, which is likely to cause damage through cell
reversal.
Though they're usually more expensive per amp hour than NiCds, NiMH
batteries have do have advantages, but avoidance of "memory" isn't really
one of them. NiMH batteries are usually lighter for a given capacity, and do
not contain Cadmium (Cd) which as a toxic metal is widely regarded as an
environmental problem. NiMH batteries are just as sensitive to damage by
over-discharge as NiCDs, and are MORE sensitive to over-charging. A battery
charger that is "smart" enough to charge a NiMH battery can be safely used
to charge a NiCd of the same voltage rating, but a charger designed for
NiCds will gradually cook a NiMH. Unless weight or environmental issues are
critical, a NiCd rebuild is often better value.
I now have a 1200 mAh battery pack that uses the original Apelco
charger.<<<<
You should urgently look into whether your battery charger is "smart" enough
to charge your new NiMH battery pack without damaging it.
I know that a lot of what I've written here is contrary to what one is
usually told. Before you dismiss it as the droolings of an idiot, please
take a look at these links:
http://www.dansdata.com/gz011.htm Australian and popularised but basically
sound.
http://www.sheldonbrown.com/marty_sla-nicad.html#memory Bicycle-related but
good fairly technical advice on batteries generally.
http://www.repairfaq.org/ELE/F_NiCd_Battery.html#NICDBATTERY_014 From
Sci.Electronics.Repair. Note that this writer states that the "memory
effect" does exist, but he defines the effect differently from everyone
else!
http://user.fundy.net/cyclist/bikecurrent-FAQ.html#sect3.24 More bicycle
lighting stuff from the Bikecurrent FAQ.
http://www.antonbauer.com/handbook/handbook.html Long and very technical
article on professional video camera batteries.
Best regards, Robert Bryett,
Sydney, Australia.
mailto:rbryett@mail.com
The NiCd Lady offered to rebuild my original ICOM M1 battery pack with NiCd
cells, as it turned out she had replacement packs on the shelf. So my M1
lives on.
mailto:nicdlady@nicdlady.com
Regards,
Jim Fuller
"Miss Em"
Santa Cruz, CA
The NiCd Lady offered to rebuild my original ICOM M1 battery pack with
NiCd cells, as it turned out she had replacement packs on the shelf. So my
M1 lives on. <<<<
That's great. Just make sure your charger is "smart" enough to keep the new
battery healthy.
I visited The NiCd Lady web site, and noticed that she sells the Maha
MH-C777 (for NiCd) and MH-C777PLUS-II (for NiCd, NiMH and LiIon) chargers.
These are excellent general purpose chargers which can accommodate many
different battery formats, and they even include a magnetic thermistor probe
you can stick on the outside of your battery pack to measure its temperature
during charging. At about US$50 for the C777 and about US$90 for the
C777PLUS-II they're probably cheaper than building your own "smart" charger
if you factor in your time and hassle.
I use and recommend these chargers BTW, but I've no interest in Maha. I'm
just a satisfied customer.
Best regards, Robert Bryett,
Sydney, Australia.
mailto:rbryett@mail.com