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Steve Tinker · 08-02-2016, 09:45 PM

As an addition to Gelbster's advice, try the following:

1) Disconnect the (-) negative battery cable & connect to your charger (not maintainer). Leave on charge or at least 7-8 hours.
2) Check voltage after disconnecting battery charger for +/- 15 minutes - fully charged battery should read 12.6v.
3) Reconnect battery and start car. Check voltage across terminals with engine running - should be 13.8 - 14.2v. If voltage significantly lower the alternator is suspect.

08-02-2016, 09:45 PM	#3
Steve Tinker Registered User Join Date: Dec 2008 Location: Queensland, Australia Posts: 1,522	As an addition to Gelbster's advice, try the following: 1) Disconnect the (-) negative battery cable & connect to your charger (not maintainer). Leave on charge or at least 7-8 hours. 2) Check voltage after disconnecting battery charger for +/- 15 minutes - fully charged battery should read 12.6v. 3) Reconnect battery and start car. Check voltage across terminals with engine running - should be 13.8 - 14.2v. If voltage significantly lower the alternator is suspect. __________________ 2001 Boxster S (triple black). Sleeping easier with LN Engineering/Flat 6 IMS upgrade, low temp thermostat & underspeed pulley. 2001 MV Agusta F4.