AE0Q,
My question was aimed at the guy suggesting a 20Ah battery
was enough. I crossed you and another reading the whole
mess. The intent is unlike you (you know your radio and
its needs) many have no idea the power needs of their radio
(IC7300 wants more) and what voltage it must have to keep
working reasonably.
I can believe 40Ah makes it but 20 would require running the
power down to keep going. I've seen more than a few either
forced to cut power or worse quit early. Also other batteries
(lead!) without battery booster will fail sooner as even 33AH
if you get 60% of the Ah before the terminal voltage starts
to fade you only got 20Ah of it. A booster has aa poer cost so
you may only get 80% ignoring that's near maximum DOD
for lead. Again understanding the battery and what the
radio will tolerate are critical.
So you used you case ( one I understand well) of 25Ah for a active
session and with 40ah that's really good. With 20Ah it would be a
short fall or require cranking down the power. Heavier radio
(power consumption wise) that would be much harder to do.
So happens I have a TT Eagle, a solid radio and fairly battery
friendly compared to some in the 100W class. RX power c
onsumption is lower than many. The exact number for mine
is 1.45A at normal speaker volume and 18A(+-) TX. The
TX current at low power is also better than most 10W out
(carrier SSB) is about 6A (with compression on), Compared
to my TT M430 Triton at .28A RX and 18A TX, the TS440S/AT
at 2.9A RX and 20A TX and doesn't go below 5A even at 5W.
That and the TS440 stretches my arm, its heavy. Oddly my
Atlas 210x, RX is well under .3A (200mA, bulbs replaced with
LEDS) and TX can peak to 18A but at reduced power its
around 10A and like many older radios without speech
processing the average power is lower. Weights about the
same as the Eagle but only 5 bands.
Just running the TT EAGLE RX only for 10 hours hits 15Ah,
I monitor a lot so I know the required power. I've sucked a
33A AGM dry with daytime ops in a contest where the full
100W SSB was needed. Add 40W or more of solar and
its adequate. Next step up for FD was 66Ah and 110W
solar, no issues for the weekend. The extra battery was
cushion against no or limited sun and the over night
stretch.
Lithium does not last significantly longer, its only lighter
(much less, maybe half) for the same AH. Depending
on the chemistry you may get more of the AH you carried
than lead without resorting to battery booster. I'm also
a user of Lithium tech especially when weight is important.
A 13Ah mil battery (195WH) I have is less than 49 ounces
(1.39Kg) and the average 8Ah gell cell is easily twice that.
The whole thing is what you can carry, how big, how heavy,
how far, and operate for how long. Also how disappointed
will one be if the battery quits before your ready to.
I do run the home station completely off solar/battery
(150ah battery and 400W solar) so I have a better idea
of what is required to make it run say a whole contest
weekend. I monitor it all with a few West Mountain Radio
PWRCheck units for charge status and load status.
Allison