NewMar PT-14W Installation And Operation Manual page 21

You may wish to purchase a set of terminal post corrosion prevention rings. These are alkali‐
saturated felt rings that slip over the battery post to reduce corrosion. Do not apply grease to
any part of the battery terminals, but you may use an occasional light spray of silicone lubricant.
Routine Checks and Maintenance
Batteries should periodically be "exercised" (slowly discharged and then recharged) to keep
them in top condition. New batteries may need to be exercised before they will be capable of
their full rating.
If your batteries are not the sealed type, distilled water should be added to them whenever
needed. The electrolyte should cover the plates by about 1/2", allowing a small air space at the
top. Do not fill the cells up to the filler cap as this could cause the battery to sputter out
electrolyte when it is being charged. Only distilled water should be used never plain tap water.
Tap water contains chemicals and elements that can alter the properties of the electrolyte,
including specific gravity. Some chemicals may also create an insulating coating on the battery
plates which will retard current flow.
The rate that water is lost by the battery is dependent on several factors; battery condition,
ambient temperature, battery use, charge voltage, etc. It is normal for batteries which are not
maintenance‐free to require topping off about once a month.
A battery's state of charge may be monitored by checking the specific gravity or by open circuit
voltage. You may use the following table to evaluate the condition of your batteries:
Battery Condition Table
Specific Gravity
Measured by
Hydrometer Open Circuit Voltage
12 Volt System
1.265 12.6 or more
1.225 12.4
1.190 12.2
1.155 12.0
1.120 11.7 or less
* Note: Wait at least 5 minutes after charging or discharging before checking specific gravity or
open circuit voltage. The battery's voltage needs to stabilize in order to get an accurate reading.
Troubleshooting Your Battery System
If your battery will not accept or hold a charge, one of the following conditions may exist:
1. A BAD BATTERY. You may have a battery with an open or shorted cell, a battery without any
"life" left. Check by charging the battery until all cells have a specific gravity of 1.225 or greater
at 80° F. If you are unable to obtain 1.225 in each cell, replace the battery.
24 Volt System
25.2 or more
24.8
24.4
24.0
23.4 or less
State of
Discharge @ 80° F
Fully Charged
25 % Discharged
50 % Discharged
75 % Discharged
100 % Discharged