[Yaesu] Yaesu LiON battery question

[mikea]

On Thu, Dec 06, 2007 at 09:45:15AM -0800, John Geiger wrote:
> What should the voltage drop to on a fully charged
> 7.4v LiON battery (used on the VX5R, VX6R, VX7R) when
> transmitting on high power?  I have a FNB-80 on my
> VX5R that shows 8.3 volts when fully charged, but when
> I transmit on high power it quickly drops to 6.8
> volts. Is this normal, or is the battery about dead
> and needing to be replaced?
> 
> In addition, I charged it overnight last night using
> the wall charger and it said still charging when I
> woke up this morning.  That is unusual as they seem in
> the past to always fully charge overnight.  The drop
> in charger will fully charge it to where the green LED
> comes on.
> 
> And people were telling me on the repeater that my
> audio would cut in and out.  The carrier whould stay,
> but the audio would drop out.  Would this also happen
> with an almost depleted battery?  Never really had
> those kinds of reports before on a Yaesu HT.

Sounds like a classic case of high internal resistance in the battery
pack, John. If that's the case, the solution may be to take it to a 
battery shop to have the individual cells checked. If only one is bad,
it could be worthwhile to have it replaced. If multiple cells are bad,
the battery store may still be able to give you a better price for a 
complete re-cell than a ham store would want for a new pack.

My local battery store has re-celled a couple of VX-150 packs for me 
at some savings over the AES/Universal price for a new pack. 

-- 
Mike Andrews, W5EGO
mikea at mikea.ath.cx
Tired old sysadmin