Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

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Load Test




1. Connect voltmeter and battery load tester across battery terminals.
2. Apply 190 ampere load for 15 seconds to remove surface charge.
3. Remove the load and wait 15 seconds to let battery recover.
4. Apply 190 ampere load. Read voltage after 15 seconds.
5. Remove the load.




- The voltage dose not drop below the minimum as listed in the figure.
Battery is good.

- The voltage does drop below the minimum as listed in the figure.
Replace the battery.

NOTE: Temperature of battery will affect minimum voltage required to pass load test.
See the figure and estimate the temperature battery has been exposed to for the last several hours.