Simple battery filler

Roger Hughes tries out an easy-to-install pipework system for keeping multiple battery electrolyte levels topped up correctly

- Roger Hughes

Britannia, my 45ft schooner, has eight golf-cart lead-acid batteries, (also called float batteries), in the house bank. They are mounted low down under the saloon floorboards in two rows, on either side of a 6.5kW diesel generator, a large water heater, and the usual conglomeration of pipes, pumps, and filters, not to mention the main mast compression post.

I also have two 12V batteries, one in the bow for the windlass, and the other aft, as a dedicated engine start battery.

That’s a total of 36 cells to check and fill from time to time. The process usually took over an hour, because the battery caps were not very easy to reach. Yet batteries are the beating heart of all boats, sail and power, and should be one of the most accessible of items.

You’d think a boat with a 14ft beam would have lots of space for batteries, but the large water and diesel tanks on each side of the hull – 280gal of fuel and 325gal of water – reduces the middle space to only 36in. Just to inspect the water level in the cells I had to first dismantle the saloon table and roll up the carpet, then lift up four large, heavy plywood floorboards plus insulation, then lay flat over the floor-beams with a flashlight to reach down and unscrew the battery caps.

If any cell needed water, I used a long, narrow funnel which I stuck in each cell, then poured water in from a gallon bottle of distilled water. It was simply guesswork how much was poured into each cell, and I know I sometimes over-filled them, but how else could they be topped-up?