Clarity on What we Build, Basic Rules of Batteries

I know that for all of the experienced builders this will seem daft, but what is the rule on batteries, the emails I have on building Lajabless and the posts on the forums seem to suggest that any battery system is allowed. I want to build a fully legal race boat, what is the definitive rule on batteries. Is it 4 AA batteries or is any system actually allowed?

Ken ~ it used to be 4 x AA’s but now use what ever you like

3 AAA Lithium Energizer non-rechargeable are becoming most popular at Tanglewood MYC as they seem to off lightest weight and smallest size.


Have a look at the Footy rules at

The significant line is immediately below the title line where it says :-

These are open class rules in which anything not specifically restricted or prohibited is permitted.

If you do a pdf search for batteries the only result refers you to :-

Rule C.2 Batteries are to be placed within the hull.

Since no mention is made of type or number of batteries, then, because of the open class rules, you can use whatever you like as long as they are within the hull. They cannot be placed in the bulb or the fin or any other appendage.

With respect to the Energiser Lithium batteries, they are indeed light weight and have a better capacity than AAA NiMh cells and hence will last longer, but I have found that when they start to die they do it very quickly with no apparent warning. I found to my cost that no load voltage checks were no use at all. In future, if I decided to try them again, I would measure the voltage when driving a dummy load pulling about 150 - 200ma. But I suspect you will still have to be prepared to have your first set spoil a perfectly good sailing day.



Thank you for the explanations on that. As I am now about to start the fitting and can use any battery system the build up is now clarified and a great deal simpler.