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Alternator query?

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So i have the standard alternator on my '95 300tdi 90 (65amp).......

Now because most of my journeys are only short distance 2.5 - 5 miles max. Is it worth putting on  a bigger aalternator ie a 120amp...... with this put more volts back into the battery quicker so be more effective with the low milage travel??? Or is there another solution to this?

Cheers Andy 

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Won't make any real difference, a car battery will only take 25 amps or so at maximum. 

So unless you have heated screens, seats, and millions of lights you won't max out the alternator.

Do you get flat batteries often?

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Cheers for the info Bowie69 and as a rule no only once in an inconvenient blue moon.....using a Numax marine leisure battery and has been in 8yrs with no major issue till now! Was flat after the coldest night and not holding charge so new one on the way.

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8 years is very good going, especially with short trips like that :) 

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Why not stick a solar panel on the roof?  I got one from ebay 120W and is only 3mm thick. Its 1m x 500mm. Stuck on the roof its not visible and is fantastic in summer and occasionally ok in winter depending on sunlight and where its parked. It puts out almost 4 amps at full whack which is enough to run a fridge all day (drawing 2.3A cyclic) AND charge the aux battery. So with only a battery to feed it would probably be fine. I think I paid £140. Beauty is its charging even when you're not moving. 

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I'd stick with what you've got: while a higher-output alternator *can* charge a modern battery a lot faster [I've seen 100A going into a TD5 battery a few seconds after a cold start] - what do you have as a drive-belt?

A single V-belt is marginal if driving a 65A alternator to full-output for significant periods: 120A alts *need* serpentine unless they're going to squeal/trash the belt in short order. Overtightening a V-belt to stop it squealing ruins the bearings...

Considering the cost, I'd stick with your existing alternator and replace the battery more regularly [3 years/30,000 miles is my 'life' for a battery - the old one then gets used to power the beer-cooler when it's summer!]

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my 100amp alternator charges fine on a single Vee drive belt, it quite capable of keeping my 2 x 900amp batteries full. 

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Have you checked how much your 100 amp alternator is feeding your batteries (and other power users?)

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2 volt meters for the batteries, not had any cause to doubt the charge rate, haven't got a good enough a metre to check output

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Ok not fully understanding the belt thing!?!

As far as i know i only have x1 belt that goes to the alternator then to the fan and up over and round other belt wheels, belts ribbed and about an inch wide, so guessing it's not "V" belt type?

Standard 300Tdi set up or have i missed a belt (God knows the wife will happily give me one!)?

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That's a serpentine belt, Mutley, so called because it weaves in and out of numerous pulleys (running them from both sides of the belt).  A V belt is the old style that sits in a V-shaped groove on each pulley, and is much narrower but deeper than a serpentine belt, seldom driving any pulleys with its back face.

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