Toro 4100-D service manual Minimum Battery Electrolyte

2. Conduct a hydrometer test of the battery electrolyte.

IMPORTANT: Make sure the area around the cells is clean before opening the battery caps.

A.Measure the specific gravity of each cell with a hydrometer. Draw electrolyte in and out of the hydrometer barrel prior to taking a reading to warm-- up the hydrometer. At the same time take the tem- perature of the cell.

B.Temperature correct each cell reading. For each 10oF (5.5oC) above 80oF (26.7oC) add 0.004 to the specific gravity reading. For each 10oF (5.5oC) be- low 80oF (26.7oC) subtract 0.004 from the specific gravity reading.

Example: Cell Temperature	100oF
Cell Gravity	1.245
100oF minus 80oF equals 20oF
(37.7oC minus 26.7oC equals 11.0oC)

20oF multiply by 0.004/10oF equals 0.008 (11oC multiply by 0.004/5.5oC equals 0.008)

ADD (conversion above)	0.008
Correction to 80oF (26.7oC)	1.253

C.If the difference between the highest and lowest cell specific gravity is 0.050 or greater or the lowest cell specific gravity is less than 1.225, charge the bat- tery. Charge at the recommended rate and time giv- en in Charging or until all cells specific gravity is 1.225 or greater with the difference in specific gravity between the highest and lowest cell less than 0.050. If these charging conditions can not be met, replace the battery.

3.Perform a high--discharge test with an adjustable load tester.

This is one of the most reliable means of testing a battery as it simulates the cold--cranking test. A commercial bat- tery load tester is required to perform this test.

CAUTION

Follow the manufacturer’s instructions when us- ing a battery tester.

A.Check the voltage across the battery terminals prior to testing the battery. If the voltage is less than 12.4 VDC, charge the battery before continuing with load testing procedure.

B.If the battery has recently been charged, apply a 150 amp load for 15 seconds to remove the surface charge. Use a battery load tester following the manufacturer’s instructions.

C.Make sure battery terminals are free of corrosion.

D.Measure the temperature of the center cell.

E.Connect a battery load tester to the battery termi- nals following the manufacturer’s instructions. Connect a digital multimeter to the battery terminals.

F.Apply a test load of 325 amps (one half the battery cold cranking amp rating) for 15 seconds.

G.Take a battery voltage reading at 15 seconds, then remove the load.

H.Using the table below, determine the minimum voltage for the cell temperature reading:

Minimum	Battery Electrolyte
Voltage	Temperature
	70oF (and up)
9.6		21.1oC (and up)
	60oF
9.5		15.6oC
	50oF
9.4		10.0oC
	40oF
9.3		4.4oC
	30oF
9.1		--1.1oC
	20oF
8.9		--6.7oC
	10oF
8.7		--12.2oC
	0oF
8.5		--17.8oC

I.If the test voltage is below the minimum, replace the battery. If the test voltage is at or above the mini- mum, return the battery to service.

Electrical System

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