J&J Amusements Bumper Boat 2014 Service Manual page 144

4-12
A SIMPLE, EFFECTIVE AND PROVEN SYSTEM
The J&J electric bumper boat utilizes four Trojan T-105, 6V Batteries rated at 225AH, and connected in series. This battery
pack was chosen to provide the best performance-to-weight ratio and has proven, since its introduction in 1996, to have
an excellent record of performance and durability.
INSPECTION
One of the top five service call questions is: "The relay clicks, but motor does not turn or turns slowly". Another is: "Why
won't my boats last all day?" Or: "They start out fine, but quickly start getting slower."
THE MOST COMMON CAUSE OF THESE TOP ISSUES ARE RELATED TO THE BATTERY PACK.
LEARNING TO TEST BATTERIES WILL SAVE YOU A LOT OF HEADACHE.
This test assumes that battery fluid levels have been maintained; note that adding water prior to testing will result in bogus
readings. If possible, charge the boat overnight prior to testing; batteries that have bad plates will still take a "surface"
charge and appear to be good, so let the pack sit for an hour after disconnecting the charger, then put a load on the system
by turning on the motor and taping the plunger down for 15 minutes (while in the water).
Shortcut Tip: At this point, back probe the charger lead with your DVOM and read the DC volts. Compare with chart
(page 5-149), to give you a quick check of the overall charge condition of the battery pack. If "charged voltage" is not
good, you can proceed with the specific gravity testing to determine which battery(ies) are causing the poor performance.
A battery cell's specific gravity is a great way of measuring a battery's state of charge. This is because during a discharge,
the specific gravity decreases relative to the ampere-hours discharged. The specific gravity also increases as the battery is
recharged.
Use a hydrometer to measure the specific gravity of the electrolyte solution in each cell. A hydrometer is a tool used to
measure the density or weight of a liquid compared to the density of an equal amount of water. A lead acid battery cell is
fully charged with a specific gravity of 1.265 at 80° F. For temperature adjustments, get a specific gravity reading and adjust
to temperature by adding .004 for every ten degrees above 80° F and subtracting .004 for every 10 degrees below 80° F.
HYDROMETER BATTERY TESTER
503-304-8899
Specifications subject to change without notice - Check our website for valuable information including videos, workshop and operations manuals. www.jjamusements.com
Draw up fluid to fill line.
Tap lightly to remove any air bubbles.
Top pointer must be vertical. Large
pointer shows specific gravity.
Check every cell recharge if reading
is less than 1.210 specific gravity.
Battery replacement indicated if more
than 30 point difference between cells.
Flush with hot soapy water to clean
and rise with clean, warm water.