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ReferenceSpecial Instruction, SEHS7633, "Battery Test Procedure"
Caterpillar Accessible Batteries
Caterpillar recommends the use of accessible batteries in all Genset applications. Accessible batteries are batteries with removable caps that allow access to check the electrolyte level or to top off the electrolyte level within the cells of the battery.
Note: Non-accessible types of batteries are Gel batteries and AGM batteries.
Genset applications commonly use a constant charge during operation. Types of constant charges are a trickle charge or a float charge. If the battery is not maintained properly, the use of these types of constant charge may shorten the life of the battery. The use of accessible types of batteries allows service to the batteries and the proper maintenance of the batteries, which includes electrolyte level check. This maximizes the life of the batteries.
Note: Use only de-ionized water or de-mineralized water within the cells of the battery.
Note: If a non-accessible type of battery is used currently, replace this battery with an accessible type of battery after 3 years. For regions with a warmer climate, replace the battery within 2.5 years. Warmer temperatures may shorten the battery life. The ideal operating temperature range for Caterillar batteries is 20 to 25 °C (68 to 77 °F).
Refer to Table 1 for the list of accessible and maintenance free accessible batteries.
Type of Battery     | ||
Group Size     | Accessible Battery     | Maintenance Free Accessible Battery     |
8D     | 101-4000     | 153-5720     |
4D     | 9X-9730     | 153-5710     |
4D     | 9X-9720     | 153-5700     |
If accessible, maintenance free design is not available, use a battery with an equivalent group size. Replace the battery after 3 years. In regions with a warmer climate, replace the non-accessible battery within 2.5 years.
Maintenance for an Accessible Type of Battery
Accessible batteries require periodic checks for proper electrolyte level. The electrolyte level should be covering the plates (grids) within the battery in order to maximize a transfer with full charge. If the liquid level is below the plates (grids), only add de-ionized water or water that is free of minerals.
Note: Never add battery acid to top off the volume as the addition of extra acid may destroy the grids.
Check the electrolyte level in the accessible batteries at every 1000 hours. In regions with a warmer climate, check the level at every 500 hours in order to ensure that the electrolyte level is 13 mm (0.5 inch) above the top of the separators.
Types of batteries should never be mixed if more than one is used. With mixed types of batteries, some batteries may be overcharged, while other batteries may not charge sufficiently. A sufficient charge may not occur as the alternator responds to the average load and voltage. If a battery system consists of a battery pack of more than one battery and one of the batteries needs to be replaced, replace all of the batteries in the battery pack.