Diesel Generator - Battery Keeps Losing Charge

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If you battery keeps discharging while on the unit, there are a few things you need to check.

1)     Charge the Battery. A short charging of a flat battery might not be enough to turn over the engine, so be sure you have charged it for over 1 hour, or until charged on a mains charger.

2)     Test the battery output with a multimeter. You should get approx. 12 vdc – 12.5 vdc if the battery is healthy. If lower than this voltage, please replace the battery.

3)     If your battery is testing correctly, this could indicate that your Battery Charging Rectifier has blown. If it has, it can blow your battery and the starter motor solenoid! If you run your equipment it should be charging the battery at 13 vdc.

You can use a multimeter to check this. If it is not charging at 13 vdc, then you will need to replace the Battery Charging Rectifier to ensure you do not find yourself in this position again, or with a more expensive repair.

4)     If there was a surge in the system from the Battery Charging Rectifier failing, or the battery being hooked up backwards, be sure to check any other 12 vdc items:

  • Switches such as the the ignition switch, idle switch, etc.
  • Solenoids in the fuel system such as on the carburetor or on fuel pumps (if fitted to your unit, etc).

If you need any Parts we sell them on our websites.

If you need any further assistance our Engineers are happy to help! Select the option below to open a support ticket with them.

Spanner Driver QUESTION

Need any more advice?

Spanner Driver Answer

No thanks! I’d like to buy some Starter related parts now.

Spanner Driver Answer

No. Thanks for your help!

Spanner Driver Answer

Yes, I need more information please from an Engineer please.