RadioBanter - View Single Post - IC-T90A external power question

December 14th 03, 04:27 AM

In article ,
(Eric Behr) wrote:

I'd like to make an external high capacity pack for my T90A
for emergencies, long special events etc. The manual isn't
very clear on this subject. I'd appreciate any comments from
those who experimented with it.

I notice that when the wall-wart charger is plugged in, the
HT won't transmit (or if it does, it has minimal power) even
when the battery pack is attached and well charged. It isn't
surprising that the normal little charger is not able to put
out enough current, so the unit must be somehow disconnecting
the battery pack when the power plug is in, and tries to draw
all the juice from the external source.

So I'm thinking of making a waist-belt pack out of 8 NiMH or
6 alkaline C or D cells (so it won't exceed the 11.5V max), a
3A fuse, plugged into the jack where the charger goes. Has
anyone done that? I'm 90% sure this will be OK, since the
charger jack is supposed to work with the ICOM cig lighter
adapter so nothing inside should go up in smoke even at full
transmit power with this arrangement. But some first-hand
experiences would reassure me quite a bit. Thanks a lot.

On mine, when the batteries are fully charged the T90 indicates Hi-V
and does not transmit. I assume that it is in self protect mode at that
time.

The manual says not to transmit with the charger plugged in (IIRC).

If I were building a battery pack, I think I would keep it at or under
11 volts for recharging or 8.2 volts for operating. (8.2 is what I see
on turn on whrn the battery has been fully charged.)

de KD5YVP