Great idea but the industry is not there yet on "self-contained" stuff. The link you posted is primarily for navigation
lights on pilings or day markers. There are a lot of small self-contained solar
powered vents and other stuff and invariably they all suffer the same problems and fail to function after a year or so.
- - The problems I have found in real life with anything using small PV solar cells to recharge a "nicad" rechargeable battery are twofold.
- - First the solar PV covering which is normally plastic gets "eaten" by the sun and crazes over making the PV panel ineffective. Of course bird poo and dirt from rain and sea accumulates on the PV surface and likewise the charging
voltage drops below a usable amount.
- - Second the rechargeable nicad batteries last about a year or so and then won't take and/or hold a charge anymore.
- - To accomplish your objective, IMHO, the best way to go LED is to get the certified LED vessel navigation
lights that are already on the market. And power them from your main battery bank with large solar PV panels
that recharge the house battery. Going small with solar PV just doesn't seem to work or hold up very long.