All good advice above.
Flooded batteries can run dry in the normal course of events
, due to several reasons including overcharging. Some evaporation can take place as well. They need to be checked regularly and topped off to the proper level (about 3/8" to 1/2" above the top of the plates). HydroCaps or WaterMiser caps can reduce the amount of electrolyte loss, thus the intervals between topping off. Still, even with these caps, it's a very good idea to check the electrolyte levels on a regular basis.
Flooded batteries in cruising service
have a lifespan of 3-5 years on average. Bad treatment can kill them in less than a year; exceptionally good treatment can extend their life by a few years.
Again, read the Trojan User's Manual. Pay careful attention to the charging recommendations. Undercharging can kill a battery as well as overcharging. You want to be sure that the onboard devices for charging (battery charger
, solar panels
, etc.) are well suited to the type of batteries you install. A mismatch here can dramatically shorten the life of your batteries.
The sad fact is that many -- perhaps most -- boat
batteries don't just die. They are murdered. The "usual suspects" are:
- bad installations;
- improper charging and charging devices;
- chronic undercharging leading to sulfation of the plates and loss of capacity;
- cycling too deeply on a regular basis;
- contamination of the electrolyte thru improper care (leaving caps off, allowing dirt or extraneous materials in, not using distilled water
to top off, etc.);
- stratification of the electrolyte caused by undercharging and lack of use and movement; and
- physical damage to the plates caused by overcharging, corrosion
, or precipitates building up underneath them and shorting them out.
Educate yourself, take care of your batteries, and you'll have a much more positive experience next go-round!