IF you have a newer H2 (Most 2013 and newer models) you should be able to easily replace it by ordering this kit: http://tournamentscales.com/battery-for-h2-scale-requires-red-connector-inside-scale-head/
To check if your H2 has a user serviceable battery watch the beginning of this video to see if you have a red connector inside the H2 unit.
If you don't have the red connector you will need to send in the unit and we can replace if for you.
Repair Instructions
1. Print and fill out this form
2. Carefully pack up scale system (Scale can be shipped directly in waterproof seahorse case no outer cardboard is required)
3. Ship unit insured to:
Pro Tournament Scales
Attn: Repair Dept.
2001 N Morton St
Franklin, IN 46131
Be sure you include your return shipping address.