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Yet another SVA question

Posted: Fri Feb 24, 2006 5:10 am
by va3wxm
Just curious: can a radio be left in the SVA for a long period of time without destroying the battery? What if the it's turned on?

SVA charger...

Posted: Fri Feb 24, 2006 5:30 am
by Tom in D.C.
The SVA charger is automatic, and the charging indicator changes from
red to green when the battery's internal resistance reaches a certain level.

If the radio requires more current when receiving than the trickle charging
rate, which is probably likely, you would eventually run down the battery,
but then I suppose the high charging rate would kick in and overcome some
or all of the battery's losses. Also depends of course on whether or not you
do any transmitting. Use a fat battery (1800 mAh or more) and you probably
won't have a problem. I find it also helps to program the transmit power as
low as you can to prolong a battery's charge.

Posted: Fri Feb 24, 2006 6:07 am
by va3wxm
Thanks for the response, Tom.

Actually, the Saber won't be doing much (if any) transmitting.

I tried out a little experiment using the shorty battery (NTN4538) and the SVA did indeed change from rapid to trickle as it should. After a day of it being in trickle mode AND the Saber turned ON the whole time (no transmitting) I pulled it out and found the battery was warm to the touch.

Not hot, simply warm.

Should I be concerned?

SVA charging, etc.

Posted: Fri Feb 24, 2006 10:49 am
by Tom in D.C.
Ask ten people on here and you'll get ten varied answers. I've always
favored letting the charger do its thing, then using the radio out of the
charger, but others will tell you it's okay to listen while charging.

I've also found the SVA charger to be not particularly fast, though as
we agree it is an automatic unit.

My personal opinion of battery heat is that warm is normal but that
hot is on its way to overcooking/overcharging. The chemical reaction
of the charging process generates heat. Fancy chargers sense the
battery's condition by measuring the internal resistance but cheaper
chargers rely on a thermostatic sensor inside the battery pack to
either open the circuit or shunt in a current-limiting resistor.

Regards,