Thread: Is a 65amp Alternator enough?

In a word yes.

It is the battery that will deliver the necesssary amps to drive the winch so this needs to be man enough. A 9500lb winch at full pull will use over 500 amps so a battery of 650cca minimum is recommended (by Warn). Obviously the winch will not need to work this hard often if at all so you are more likely to only use half of that (250amp).

The alternator will obviously need to replenish this when you are not winching. The bigger the alternator the faster the charge rate, so a small alternator will do, it will just take longer.

It is not recommended to run electric winches too long to allow for the heat generated to be dissapated and to allow for the battery to recover.

The 65 amp alt in the Defender doesn't have a sealed rear bearing, and every so often, say 20,000km, you should inspect / clean / grease it. It doesn't take long.

The 100amp from the 300Tdi disco is a better sealed unit and will fit straight in, so when it comes time to replacing, you may as well get a Disco one. I don't know how Land Rover's research suggested that a school taxi would need more electrical charging capacity than an expedition vehicle, but perhaps it's because the school taxi gets shorter runs. It couldn't possibly have been a budgetry constraint.

Originally Posted by Michael2

The 65 amp alt in the Defender doesn't have a sealed rear bearing, and every so often, say 20,000km, you should inspect / clean / grease it. It doesn't take long.

The 100amp from the 300Tdi disco is a better sealed unit and will fit straight in, so when it comes time to replacing, you may as well get a Disco one. I don't know how Land Rover's research suggested that a school taxi would need more electrical charging capacity than an expedition vehicle, but perhaps it's because the school taxi gets shorter runs. It couldn't possibly have been a budgetry constraint.

Electric windows, Central locking, Climate control...etc. etc.
Andrew if you have a deep cycle battery make sure you dont run the winch off it, otherwise you will bugger it (D/C battery that is), BTW 65 amps is plenty, Regards Frank.