[aprssig] flying digipeater?

[Scott Miller]

True, but they've got some batteries for high-current pulse applications
that might be suitable...

http://www.tadiranbat.com/plusesplus.php

I think SAFT and others have similar offerings.

Scott
N1VG

----- Original Message ----- 
From: "Robert Bruninga" <bruninga at usna.edu>
To: <aprssig at lists.tapr.org>; <scott at opentrac.org>
Sent: Monday, April 18, 2005 3:55 PM
Subject: Re: [aprssig] flying digipeater?


> >(non-rechargable) Tadiran 3.6V AA, 2400mAh,
> >The D cells offer (19 amp hours), albeit at $18 each.
>
> But these cells have very high internal resistance and wont
> even power an HT on transmit.  We are using 112 of
> these D cell lithiums on our ANDE satellite to get a year
> life for our flying digi...  But to get rated life, you cannot
> draw more than 50 mA per cell..
>
> We series them four high to get over 12 volts and then
> 28 strings IN PARALLEL. to get life and to also get enough
> transmit current to drive 500 mA 2m transmitter.
>
> Think of these very high density lithiums as just very-big
> watch batteries.  They have tremendous capacity but
> only if you draw a few milliamps..
>
> Bob
> WB4APR
>
>