What brand / where to buy battery / charger ?

I'd recommend using a LiFePO4 battery for the long haul if you have the money.  I don't have this brand but I like the fact that it has a battery power capacity indicator.   

http://www.batteryspace.com/LiFePO4-Battery-12V-9Ah-108Wh-18A-rate-with-LED-Indicator.aspx

I bought one from them without the capacity indicator. I like it very much. No worries about maintaining a minimum charge. It IS pricier than SLA batteries and there usually is a hazardous item shipping charge but if you can get someone to deliver to you, it's worth it. The battery only weighs a little over 1 pound. Their charger works too, although they did a shoddy of job of connecting the clips to the wires...easily solved. The company is located in Richmond.

Is there an advantage to the big bricks?  I've been using the small 1.2mh ones from Fry's and they easily last a several trips without charging, weigh very little, and fit in small tupperware containers.  Those bricks are hefty.

Thanks all for the information guys....

I have the same one from HD for the Mighty Mule.  They also have various size bricks used for emergency lighting & exit signs in the lighting department (near the flour. light fixtures).  I went with the Mighty Mule because it fit the exact size I needed & cost me $15 after a $5 off coupon.

   One 'Red Flag' I noticed when looking at all the H.D. batteries ..... CHECK THE DATE!  Some of the ones in the lighting section were over 2-years old.  They apparently didn;t have a high turn over rate of them.  The Mightly Mule I bought was only 1 month old.

~Bill

P.S.  There is a "trick" for saving money at H.D.  It has a little something to do with them taking competitor coupons (except Harbor Freight).  ACE Hardware ALWAYS has good coupons that H.D. will honor.  My savings this year is averaging 25% with purchases almost daily there.

Thanks for the great tips Bill , I'll keep it a secret