[Elecraft] Two battery questions - K2 portable operations

[Doug Forman]

Thanks to everyone who responded publicly and privately regarding my K2 
portable battery questions.  Very helpful information was shared and I 
certainly learned more about using SLA batteries generally, and in 
combination with each other too.

Here are some of the suggestions gleaned from multiple emails:

1.  In a perfect world, it's not advisable to connect two identical SLA 
batteries in parallel  (since if one battery is lower than the other, 
the high one will discharge into the lower one in an attempt to charge 
it and equalize voltages.)  Instead, use a switch, or a battery isolator.

2.  Don't let the battery voltage drop below approx 10.5v on a 12v 
battery to prevent damage to the battery.

3.  Keep batteries charged using a trickle charger when not in use (I 
use an A&A Engineering "Smart Battery Charger")

4.  Consder the relative weight of the battery for portable ops.

5.  Don't attempt to charge a SLA battery directly from a solar panel 
without a charge controller.  (found a 10/2001 QST article featuring the 
SunLogic Micro M+ Charge Controller that looks appealing!)

6.  Some ARES folk like 17Ah SLA's for portable ops, commenting that 
they "are a great size for portable backpack operation". 
(www.eham.net/articles/2228)

Thanks to everyone for responding!

73,

Doug - N7BNT