This appears to be a very "standard form factor" product; you can find batteries with exactly the same physical and electrical specs online from a dozen or more different manufacturers. It is a standard battery for use in UPS systems.
While I don't know what brand Neil is providing, I found a spec sheet for one manufacturer's similar product, which I have posted to my web site in a folder where anyone can download it, at https://files.me.com/lewphelps/mxvahl. It's a 483kB PDF file. What the power curves show is that it will run for just under 4 hours at a draw of 1 amp before it drops to 11.0 volts, which means you could run a K3 in receive only on one battery for that time (nominal 0.9 amp RX draw with no sub receiver). With a draw of 4 amps (TX nominal for K-10 is 3 to 4 amps) the battery drops to 12.0 volts in about 30 minutes (eyeball extrapolation of curves; use with caution). I think a reasonable way to think about battery life would be to run them in parallel but assume one battery is providing RX current and the other TX current; hence, you with a pair of batteries in parallel you could receive for 4 hours and transmit for half an hour before you dropped below 11.5 volts. Each battery weighs 4.19 lbs. and measures 4.17" height (excluding connecting tabs) x 3.98 x 3.54 inches. These batteries are too big to put inside either a K2 or K3. (The "stock" K2 internal battery has 2.9 ah capacity.) If one were to build an external power supply box roughly the size of a K3 case, it could contain six batteries and the charger circuit, and would weigh about 28 lbs. Assuming a 20% transmit duty cycle, this "six pack" would keep a K3 running for about 8 hours. YMMV. Lew K6LMP ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
