Guardian Technologies 4270 Effects of Temperature, Adding Water, Checking Battery State of Charge

							Section 5
							ENGINE DC CONTROL SYSTEM
TERMINALS:	7	8	9	10	11	12	OVERSPEED

SHUTDOWN

POTENTIOMETER

GREEN LED

RED LED

TERMINALS: 1 2 3 4 5 6

Figure 5-4 – Engine Control Circuit Board

battery and starter should not exceed 0.12 VDC per 100 amperes of cranking current.

Select the battery cables based on total cable length and prevailing ambient temperature. Generally, the longer the cable and the colder the weather, the larg- er the required cable diameter.

The following chart applies:

CABLE LENGTH (IN FEET)	RECOMMENDED CABLE SIZE
0-10	No. 2
11-15	No. 0
16-20	No. 000

EFFECTS OF TEMPERATURE:

Battery efficiency is greatly reduced by a decreased electrolyte temperature. Such low temperatures have a decided numbing effect on the electrochemical action. Under high discharge rates (such as crank- ing), battery voltage will drop to much lower values in cold temperatures than in warmer temperatures. The freezing point of battery electrolyte fluid is affected by the state of charge of the electrolyte as indicated below:

SPECIFIC GRAVITY	FREEZING POINT
1.220	-35° F. (-37° C.)
1.200	--20° F. (-29° C.)
1.160	0° F. (-18° C.)

ADDING WATER:

Water is lost from a battery as a result of charging and discharging and must be replaced. If the water is not replaced and the plates become exposed, they may become permanently sulfated. In addition, the plates cannot take full part in the battery action unless they are completely immersed in electrolyte. Add only

DISTILLED WATER to the battery. DO NOT USE TAP WATER.

NOTE: Water cannot be added to some “mainte- nance-free” batteries.

CHECKING BATTERY STATE OF CHARGE:

Use an automotive type battery hydrometer to test the battery state of charge. Follow the hydrometer manu- facturer's instructions carefully. Generally, a battery may be considered fully charged when the specific gravity of its electrolyte is 1.260. If the hydrometer used does not have a “Percentage of Charge” scale, compare the readings obtained with the following:

SPECIFIC GRAVITY	PERCENTAGE OF CHARGE
1.260	100%
1.230	75%
1.200	50%
1.170	25%

CHARGING A BATTERY:

Use an automotive type battery charger to recharge a battery. Battery fluid is an extremely corrosive, sulfu- ric acid solution that can cause severe burns. For that reason, the following precautions must be observed:

•The area in which the battery is being charged must be well ventilated. When charging a battery, an explosive gas mixture forms in each cell.

•Do not smoke or break a live circuit near the top of the battery. Sparking could cause an explosion.

•Avoid spillage of battery fluid. If spillage occurs, flush the affected area with clear water immediately.

•Wear eye protection when handling a battery.

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