seems like a good fit, but is not as big as they make it out to be.
specs are wierd 74WH only equals 20000 mAH at 3.7V
AD2k (assuming 12V input) = 12V * 800 mA = 9.6W
74 WH / 9.6 W = about 7 hours of AD2K ,which would make it a good field battery, if not a little on the larger side. its not huge or anything.
ill bet its a nominal 9ish V and theyre stepping it up, so it may not be as efficient at 12V. hard to say i'd guess 5000-6000 mAh at 12V
batteryspace has a ton of options , though their packs are a little more 'bomb-looking', and many of them obviously are meant for use inside an enclosure of sorts (ie they arent meant to have plugs attached directly to the thin-gauge wires with no strain relief.) the ones with the 'trail-tech' plugs are prob. robust enough, you DEFINITELY want one with a protection ic, fuel gage is a nice touch but not required
if i'm not mistaken, what they call '11.1V' is closer to end point voltage, and this pack would run from 12.6V full to 10.8V empty, perfect for the ad2k (same voltage profile as my homebrew unit). the huge advantage of this is by using the native voltage of the packs and not stepping it up or down, you dont have the typical 5-15% efficiency loss of a power converter. the downside is you lose the lower 20% of capacity (which usually tails off rapidly anyway). lower limit of ad2k is 10V before you start to lose headroom, though you can run it as low as 9V if not pushing the levels over -6dB (he-he, preamps are for pussies, remember
)
they spec their 11.1 gauge as such:
* 0% LED Flashing pack voltage < 9.0V ( must recharge battery )
* 1 LED = 20% pack voltage: 9.0-9.9V (battery need recharging)
* 2 LED = 40% pack voltage: 9.9-10.50V
* 3 LED = 60% pack voltage: 10.50-11.40V
* 4 LED = 80% pack voltage: 11.40-12.0V
* 5 LED = 100% pack voltage: 12.60-12.60V ( battery is fully charge)
so this 4800 mah 11.1V is a little cheaper, and half the size of the one you were looking at, but its sans fuel gauge:
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=2009if you were gonna run it from 12.6 down to 10V, id guess you'd get 70% out of that battery before you hit 10V, so 4 1/2 hrs. thats about right for a typical field outing. and youd have another 30-45 minutes if you really wanted to run it into the red
this looks bomber: (no fuel gauge):
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=3864heres a cruder one, with fuel gauge tho:
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=3273keep in mind that the ad2k wants 10V or greater, and steps it down. i beleive extra voltage is just dissipated as heat.
so perhaps a 14.4V battery stepped down to a regulated 10V wit hthis:
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=299would be a decent option, if its over 90% efficient.
as you can see, there are many ways to skin a cat!
another good one:
http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=3661This looks like a good option, too, for those too lazy or incapable. (I'm the latter)
http://cgi.ebay.com/NEW-Universal-External-High-Cap-20Ah-Battery-for-laptop_W0QQitemZ120285336840QQihZ002QQcategoryZ64472QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
20,000mAh for $129.00. Outputs 12v and 5v via USB. It can output both at the same time so I should be able to power my MT and AD2K+ off this bad boy for a long long time. Jamie, can you comment on this option?
Jesse