Fortunately, you can easily do a basic health checkup on any type of lead acid battery by hooking it up to a simple-to-use digital voltmeter. If you have an open-cell battery that lets you access the liquid inside, you can do a more rigorous checkup with a battery hydrometer.
Checking an open-cell lead acid battery—that is, a lead acid battery with caps that can be opened to access the liquid inside—with a battery hydrometer is most accurate when the battery is fully charged. Closed-cell lead acid batteries without the access caps cannot be tested this way.
Charge the battery fully at least 8 hours before testing it. Lead acid batteries recharge in various manners based on their function and manner of installation. For a lead acid vehicle battery, drive the vehicle around for at least 20 minutes. For a lead acid battery connected to solar panels, let the battery charge fully on a sunny day.
In this video, applications engineer Barry Bolling uses a GS610 source measure unit to perform a charge-discharge test on a lead acid battery to show how to test lead acid battery capacity. The GS610 is made up of a programmable current and voltage source, a voltmeter, and an ammeter. Each function can be combined into numerous operation modes.
The battery capacity test measures how much capacity (current x time) in ampere-hours, Ah, the battery can deliver before the terminal voltage is reached. The measurement assumes the current flow shall be maintained at a constant rate. For a lead-acid battery, the test time is approximated to be near the battery’s duty cycle.
Adjust your specific gravity reading based on the liquid’s temperature. The specific gravity chart for lead acid batteries assumes a liquid temperature of 80 °F (27 °C). That said, the liquid in your battery probably isn’t at this ideal temperature.
Source measure units, devices that function both as a power supply and a multimeter/electronic load, are ideal for these types of tests. In this video, applications engineer Barry Bolling uses a GS610 source measure unit to perform a charge-discharge test on a lead acid battery to show how to …