The best place I have found to buy Odyddey batteries: Batterymart.com
https://www.batterymart.com/c-odyssey-batteries.html
If you want less weight do not buy the MJ series (metal jacket). Your other question was about chargers, I do have their charger. Here is a list of approved chargers for their batteries.
http://www.odysseybattery.com/docume...V_chargers.pdf
Sean