Cal Boats CAL 27 Mk III, Owner'S Manual

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BASIC RULES FOR BATTERY CARE AND MAINTENANCE

BASIC RULES FOR BATTERY CARE AND MAINTENANCE

Check liquid level in all cells once every week or two . Add water as required . Bring liquid 

level to 3/8 inch above top of separators . It is much better to add water in small amounts 
frequently, than to put too much in and flood out the electrolyte, thus causing damage to 
adjacent wiring and equipment, plus loss of acid . Generally, the local drinking water in the 
United States is safe for use in batteries; but to be sure, check with your battery supplier .

1)  Add water only . Add no battery dopes, special liquid, or powders . These are harmful or useless . 

Before adding water, take a hydrometer reading of one cell . (Don’t use same cell each time; 
change around) . If above 1 .225 Specific Gravity, battery is sufficiently charged .
If below 1 .225 Specific Gravity, remove battery for bench charge . If level is too low to read, add 
water and take hydrometer reading the next day .

2)  After adding water, examine hold-downs . Make certain battery is secure . Hold-downs should 

make a snug fit, but not necessarily the tightest fit, or the container may be forced out of shape .

3)  Examine cables and terminals for tightness, corrosion, and wear . Corrosion occurs from the 

spilled electrolyte getting on metal, other than lead . Lead does not corrode . To remove corro-
sion, scrape or brush it off . Then immerse the part in an alkaline solution, such as baking soda, 
in the proportions of one pound soda to a gallon of water . One can tell when the electrolyte 
is neutralized by observing when the bubbling stops . Wash with water, dry, and apply silicone 
grease available from battery dealers .

4)  Examine battery for broken or cracked covers, case, and cracks in sealing compound . If any of 

the above defects are present, remove battery at once and have repaired . Acid loss  from any 
of the above defects will shorten battery life . Acid escaping through cracked covers or sealing 
compound will cause corrosion of terminals, cables, carrier, and adjacent parts .

5)  Batteries should be re-charged, if hydrometer reading is below 1 .225 . DO NOT LEAVE A BATTERY 

ON CHARGE FOR MORE THAN 48 HOURS .

6)  STOP CHARGE when two hydrometer readings recorded two hours apart show no increase, or 

when terminal voltage readings recorded two hours apart show no increase . If there is no rise 
in voltage or specific gravity in a period of two hours, further charging is USELESS and MAY 
DAMAGE BATTERY BEYOND REPAIR . Have your supplier check battery for possible acid adjust-
ment or repair .

7)  On this bench re-charge, the specific gravity is expected to read certain values before considered 

serviceable for continued use . The hydrometer reading should be above 1 .260 . The full charge 
gravity when new was 1 .270–1 .290 . If battery does not register as above, have your battery 
supplier inspect it . He may be able to adjust acid or make repairs .

8)  In cold weather, do not fill cells with water and let stand without running motor long enough to 

allow water to mix with acid, as freezing might occur .

9)  Spare batteries should be re-charged at least every 4 or 5 weeks, in order that the Specific Grav-

ity may be maintained  at 1 .240 or above .

10)  Use a battery with sufficient ability to carry the connected load .
11)  Wash dirt and corrosion off top of battery to eliminate inter-cell discharge .