Yea you are killing your batteries if you dont use a charge co troller on your panel(s). Been there done that.

Sent from my iPhone

On Jan 22, 2013, at 12:39 PM, dhanson928@gmail.com <dhanson928@GMAIL.COM> wrote:

> For over 10 yrs I've been using a Siemens solar panel, no specific output  designation.  M-20 model #.  22"x 12".  I've never had a controller, just plugin to the system and unplug at dark.  Am I killing batteries too quickly, doing this?   I am about to replace another napa 42 group batt that isn't holding a chArge well, dated Jan '11.  This is my coach battery, often run way down...  I know, wrong battery, etc...but my question is -- would it  be worth it to  buy a controller of some sort, perhaps to get longer battery life, keeping all else the same?  I like everything as is, it fits, it's cheap, it works for me....am I sometimes cooking the batteries?  This is about average for the battery life...3rd Napa one 4 me.
>
> Sent from my HTC smartphone on the Now Network from Sprint!
>