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I would like to fit a larger capacity alternator to my 3 cylinder Barrus shires diesel has anyone done this and if so what alternator is possible? I really would like 120 or more

Asked by: ian  | 4.22pm, Monday 10 August

WW says:

The three cylinder 35hp Barrus Shire is offered as standard with a 50amp starter and 140amp domestic alternator, so it should not be a problem to fit a larger (or even twin) alternator.
You might find adding a second, slightly larger (assuming you have a 50amp as standard) easier than just one big alternator- it would also give you redundancy against one failing.
Using a digital alternator controller (like the Sterling alternator to battery controller) you could take two alternator outputs and combine these to charge domestic and starter banks, with the control of a four-stage charging profile. This could mean that you could actually use a smaller alternator, but achieve a faster battery recharge rate.
Often adding a larger alternator does not significantly increase the useable capacity of the battery bank- as the standard regulators fitted will soon shut down the output so that trickle charging rates are achieved quite quickly. An external alternator controller can help increase battery charging rates, as well as the depth of charge- just keep an eye on the electrolyte levels of the battery bank.
E P Barrus (or their dealers) will be able to provide all the parts needed to either add a larger single alternator, or convert to a twin-alternator set-up, as well as providing advice on installation.

Mark Langley  | 10.19AM, Tuesday 11 August

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