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Mark Hindley September 17th 04 09:07 AM

Handheld VHF battery
 
Hi,

I have a SX Micro-90 handheld VHF. Reception is good, but battery life
only a few minutes if you start transmitting.

Does anyone know who made these? Is it possible to get new/upgraded
battery packs for them? I'm in the UK.

Thanks

Mark

Ed September 19th 04 05:48 PM

I don't know about that particular brand but most are just battery packs
with AA cells in them. I have taken them apart before and swapped the
cells and resoldered them.... (Be carefull with the solder gun...)

Icom got smart and supplies a AA battery case with replaceable
nicad/nimh cells...

Mark Hindley wrote:
Hi,

I have a SX Micro-90 handheld VHF. Reception is good, but battery life
only a few minutes if you start transmitting.

Does anyone know who made these? Is it possible to get new/upgraded
battery packs for them? I'm in the UK.

Thanks

Mark



Jeff Morris September 19th 04 09:28 PM

I've done the same. The easiest replacements are the 2 and 3 cell packs
designed for cordless phones. They already have the wires attached.


"Ed" wrote in message
. ..
I don't know about that particular brand but most are just battery packs
with AA cells in them. I have taken them apart before and swapped the
cells and resoldered them.... (Be carefull with the solder gun...)

Icom got smart and supplies a AA battery case with replaceable
nicad/nimh cells...

Mark Hindley wrote:
Hi,

I have a SX Micro-90 handheld VHF. Reception is good, but battery life
only a few minutes if you start transmitting.

Does anyone know who made these? Is it possible to get new/upgraded
battery packs for them? I'm in the UK.

Thanks

Mark





Mark Hindley September 20th 04 02:25 PM


Thanks, I have opened the battery pack, and it is 8 AA in series, as
predicted. If The pack is labelled 600mAh. Presumably they are NiCads.

If I changed to 1200mAh or more NiMH, is the charger going to need
changing? It is nominal 12V supply, and just has a large ceramic
resistor and a diode inside. Do NiMHs need a different charging
current/voltage?

Mark

Gordon Wedman September 21st 04 12:20 AM

I looked into this charging question recently and it seems you can leave
NiMH batteries on a charger for an indefinite time if the charging current
is limited to 1/10th of the capacity. In your case 120 milliamps. I don't
think voltage matters other than a higher voltage will cause a higher
charging current. For a short period of time you can charge them at a
higher current, at least up to their mAh rating.
I would try to get the highest capacity NiMH batteries that I could find.
This seems to be around 2400 mAh.

On the West side of the Atlantic there are vendors who will rebuild battery
packs for you. Just send in the old one and specify your requirements.
Don't know the costs though. May be uneconomic in many cases.
I would think there would be similar services in the UK.

"Mark Hindley" wrote in message
...

Thanks, I have opened the battery pack, and it is 8 AA in series, as
predicted. If The pack is labelled 600mAh. Presumably they are NiCads.

If I changed to 1200mAh or more NiMH, is the charger going to need
changing? It is nominal 12V supply, and just has a large ceramic
resistor and a diode inside. Do NiMHs need a different charging
current/voltage?

Mark




Markus Baertschi September 21st 04 04:55 PM

Mark Hindley wrote:
Thanks, I have opened the battery pack, and it is 8 AA in series, as
predicted. If The pack is labelled 600mAh. Presumably they are NiCads.

If I changed to 1200mAh or more NiMH, is the charger going to need
changing? It is nominal 12V supply, and just has a large ceramic
resistor and a diode inside. Do NiMHs need a different charging
current/voltage?

Mark


Mark,

I'd go with brand-name cells and a new, intelligent charger.
NiMH's will have more capacity then NiCD's, but the self-discharge rate
of NiMH's is worse. After 3 months off the charger the NiCD's will have
more charge left then the NiMH's. If you recharge regularly the NiMH's
have more capacity and no memory effect.

I'm using a Maha-C777 Plus-II for my charging needs. You can convert the
old charger into a accessory to the Maha (mechanics and contacts).

Markus

jmartinw June 27th 05 05:36 PM

Could anyone tell me the size of the jack that fits into the charger socket on the body of the SX-Micro 90 radio.?

thanks
Martin West




Quote:

Originally Posted by Gordon Wedman
I looked into this charging question recently and it seems you can leave
NiMH batteries on a charger for an indefinite time if the charging current
is limited to 1/10th of the capacity. In your case 120 milliamps. I don't
think voltage matters other than a higher voltage will cause a higher
charging current. For a short period of time you can charge them at a
higher current, at least up to their mAh rating.
I would try to get the highest capacity NiMH batteries that I could find.
This seems to be around 2400 mAh.

On the West side of the Atlantic there are vendors who will rebuild battery
packs for you. Just send in the old one and specify your requirements.
Don't know the costs though. May be uneconomic in many cases.
I would think there would be similar services in the UK.

"Mark Hindley" wrote in message
...

Thanks, I have opened the battery pack, and it is 8 AA in series, as
predicted. If The pack is labelled 600mAh. Presumably they are NiCads.

If I changed to 1200mAh or more NiMH, is the charger going to need
changing? It is nominal 12V supply, and just has a large ceramic
resistor and a diode inside. Do NiMHs need a different charging
current/voltage?

Mark



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