Winter Storage Of Batteries - Mercury 150 EFI Service Manual

CHARGING & STARTING SYSTEM
4. To check battery voltage while cranking engine with electric starting motor, place RED
(+) lead of tester on POSITIVE (+) battery terminal and BLACK (–) lead of tester on
NEGATIVE (–) battery terminal. If the voltage drops below 9-1/2 volts while cranking,
the battery is weak and should be recharged or replaced.

Winter Storage of Batteries

Battery companies are not responsible for battery damage either in winter storage or in
dealer stock if the following instructions are not observed:
1. Remove battery from its installation as soon as possible and remove all grease, sul-
fate and dirt from top surface by running water over top of battery. Be sure, however,
that vent caps are tight beforehand, and blow off all excess water thoroughly with com-
pressed air. Check water level, making sure that plates are covered.
2. When adding distilled water to battery, be extremely careful not to fill more than 3/16
in. (4.8 mm) above perforated baffles inside battery. Battery solution or electrolyte ex-
pands from heat caused by charging. Overfilling battery will cause electrolyte to over-
flow (if filled beyond 3/16 above baffles).
3. Grease terminal bolts well with 2-4-C Marine Lubricant and store battery in a COOL-
DRY place. Remove battery from storage every 30-45 days, check water level and
put on charge for 5 or 6 hours at 6 amperes. DO NOT FAST CHARGE.
4. If specific gravity drops below 1.240, check battery for reason and recharge. When
gravity reaches 1.260, discontinue charging. To check specific gravity, use a hydrom-
eter, which can be purchased locally.
5. Repeat preceding charging procedure every 30-45 days, as long as battery is in stor-
age, for best possible maintenance during inactive periods to ensure a good service-
able battery in spring. When ready to place battery back in service, remove excess
grease from terminals (a small amount is desirable on terminals at all times), recharge
again as necessary and reinstall battery.
Page 2B-6 90-883728 JULY 2001