Greetings

I am in the process of putting together (battery power supply) for my
amateur radio equipment....I have an ic 735 and ic 275a.

I have a number of rechargable nicad batteries 4.400 amp hour and 7.0 amp
hour.. 1.25 volts..

I need some information about the ic equipment which I can't seem to find in
the manual...
In the manual the d.c. input reads 12 volts...

Can someone tell me what the safe upper limit of these radios tend to be?

I don't plan to come anywhere need the upper limit but I would perfer to
make a battery pack containing 12 x 1.25 volt cells rather than 11 cells.

My battery analyzer, cadex 7000, can only analyzer a series string of 1 to
12 cells.

Larry ve3fxq

On Thu, 15 Jan 2004 02:20:46 GMT, "larry" wrote:

Greetings

I am in the process of putting together (battery power supply) for my
amateur radio equipment....I have an ic 735 and ic 275a.

I have a number of rechargable nicad batteries 4.400 amp hour and 7.0 amp
hour.. 1.25 volts..

I need some information about the ic equipment which I can't seem to find in
the manual...
In the manual the d.c. input reads 12 volts...

Can someone tell me what the safe upper limit of these radios tend to be?

I don't plan to come anywhere need the upper limit but I would perfer to
make a battery pack containing 12 x 1.25 volt cells rather than 11 cells.

My battery analyzer, cadex 7000, can only analyzer a series string of 1 to
12 cells.

Larry ve3fxq


My Icom 735 manual specifies the power supply requirements: 13.8V DC,
plus or minus 15%, negative ground.

At 200 watts input, it pulls about 20 amps. Receiving, about 1.5 amps,
or 1.2 amps, squelched.

Later in the manual, it says for battery power, you can go with 12 to
15 volts.

It also mentions that anything over 15 volts may damage the rig.

Bob
k5qwg

I have a number of rechargable nicad batteries 4.400 amp hour and 7.0
amp hour.. 1.25 volts..

I need some information about the ic equipment which I can't seem to
find in the manual...
In the manual the d.c. input reads 12 volts...

Can someone tell me what the safe upper limit of these radios tend to
be?

I don't plan to come anywhere need the upper limit but I would perfer
to make a battery pack containing 12 x 1.25 volt cells rather than
11 cells.


A fully charged NiCd battery, in good condition, usually tops out about
1.4 volts. If you charge up a string of 12 batterier, this will reach
about 16.8 volts; definitely has the potential to damage your radio.

Even a string of 11 can be fully charged to 15.4 volts.... still risky
to your radio. If I had no other battery options, I'd go with a string
of 10. Fully charged they'll reach 14.0 volts, and probably rapidly drop
to 12 volts (1.2 nominal volts per cell) shortly after you begin using
them. This is a bit on the low side, but at least safer.

Personally, I'd go with a nice Lead Acid type 12 volt battery. Your
4AH cells are way too low current capability for that IC735
Transmitter,anyway.


Ed WB6SAT

This responce is to both Bob and Ed...

Actually my plan is to parallel at least 2, if not more, of these nicad
batteries together...

With your comments I think I may start out at 10 cells....

Thank you, muchly, for your input....appreciated...

Larry ve3fxq




"Ed G." wrote in message
. ..


I have a number of rechargable nicad batteries 4.400 amp hour and 7.0
amp hour.. 1.25 volts..

I need some information about the ic equipment which I can't seem to
find in the manual...
In the manual the d.c. input reads 12 volts...

Can someone tell me what the safe upper limit of these radios tend to
be?

I don't plan to come anywhere need the upper limit but I would perfer
to make a battery pack containing 12 x 1.25 volt cells rather than
11 cells.


A fully charged NiCd battery, in good condition, usually tops out about
1.4 volts. If you charge up a string of 12 batterier, this will reach
about 16.8 volts; definitely has the potential to damage your radio.

Even a string of 11 can be fully charged to 15.4 volts.... still risky
to your radio. If I had no other battery options, I'd go with a string
of 10. Fully charged they'll reach 14.0 volts, and probably rapidly drop
to 12 volts (1.2 nominal volts per cell) shortly after you begin using
them. This is a bit on the low side, but at least safer.

Personally, I'd go with a nice Lead Acid type 12 volt battery. Your
4AH cells are way too low current capability for that IC735
Transmitter,anyway.


Ed WB6SAT

Connecting batteries in parallel is not a good idea.
They will begin to discharge each other.

My .02

'73
Pat

Connecting batteries in parallel is not a good idea.
They will begin to discharge each other.


I agree with that. Plus, if that guy plans on using the IC-735
transmitter at anywhere near its full power capability, even 2 4.5AH
batteries paralleled would be insufficient current capability. I don't
understand why someone would want to go to such lengths to use a bunch of
NiCd cells when the cost of a small automotive or motorcycle 12V lead acid
battery isn't that much, and would work much better.



Ed

Connecting batteries in parallel is not a good idea.
They will begin to discharge each other.


I agree with that. Plus, if that guy plans on using the IC-735
transmitter at anywhere near its full power capability, even 2 4.5AH
batteries paralleled would be insufficient current capability. I don't
understand why someone would want to go to such lengths to use a bunch of
NiCd cells when the cost of a small automotive or motorcycle 12V lead acid
battery isn't that much, and would work much better.



Ed

"larry" wrote in message . cable.rogers.com...
This responce is to both Bob and Ed...

Actually my plan is to parallel at least 2, if not more, of these nicad
batteries together...

With your comments I think I may start out at 10 cells....

Thank you, muchly, for your input....appreciated...

Larry ve3fxq

Even that won't last too long. Myself, I wouldn't bother with those
small batteries unless you only plan to be on for a short time. Even
if you used 10 of the 7 amp/hr batteries, thats only 70 amp/hrs. Not
really too much for a 100w out HF rig. You have to worry about the
voltage drop/stability also, which BTW , Icoms are picky about.. Might
run the smaller 2m radio ok though..I use lead acid batteries for 100w
HF rigs. Preferably deep cycle, but a car battery will do fine as long
as you don't let it discharge too much to damage it. I run my ic-706
on a car battery and automatic charger here in the house.
MK

Connecting batteries in parallel is not a good idea.
They will begin to discharge each other.

My .02

'73
Pat

"larry" wrote in message . cable.rogers.com...
This responce is to both Bob and Ed...

Actually my plan is to parallel at least 2, if not more, of these nicad
batteries together...

With your comments I think I may start out at 10 cells....

Thank you, muchly, for your input....appreciated...

Larry ve3fxq

Even that won't last too long. Myself, I wouldn't bother with those
small batteries unless you only plan to be on for a short time. Even
if you used 10 of the 7 amp/hr batteries, thats only 70 amp/hrs. Not
really too much for a 100w out HF rig. You have to worry about the
voltage drop/stability also, which BTW , Icoms are picky about.. Might
run the smaller 2m radio ok though..I use lead acid batteries for 100w
HF rigs. Preferably deep cycle, but a car battery will do fine as long
as you don't let it discharge too much to damage it. I run my ic-706
on a car battery and automatic charger here in the house.
MK