Getting More Power From Alternator

[Nishan.dj]

Hi experts,

I kindly need your advice on the following matter. What makes it possible to increase the amount of amps produced by an alternator of a Mitsubishi 4DR5 J44 jeep? I got few suggestions and will list it as;

1. Rewind the alternator

2. Re-size the pulley (I think to make it fast)

I do not know any of those are practical. However without replacing, what ways I can think of getting more power from the current alternator? I really appreciate if you could share the experience. Thanks.

PS: With the load of AC, Headlights and other electrical stuff, it seems there is more power needed. However I didn't test properly and looking for ways that I can follow if in case a higher amperage is needed. Therefore your replies are highly appreciated.

Edited February 7, 2014 by Nishan.dj

[Watchman]

"more power" is a pretty subjective term. Do you currently have an amp meter in your jeep? If so the first thing is that you need to know if you really NEED to upgrade your alternator. With the headlights, AC and any other heavy loads, the battery should be charging just a tad bit. If yours does that you have no problems.

[Nishan.dj]

"more power" is a pretty subjective term.

I need to get more amps from the current alternator if possible.

Do you currently have an amp meter in your jeep? If so the first thing is that you need to know if you really NEED to upgrade your alternator.

Yes I have. And also a volt meter. I may need to upgrade & will do a load test soon.

If it needs more amperage, what would you suggest? Replace with a new alternator that can produce higher amperage? Rewind the one having now? Or any other suggestion?

Thank you Watchman for the replies.

Edited February 7, 2014 by Nishan.dj

[Rumesh88]

As Watchman says above you must asses your requirement more objectively and upgrading to a higher capacity alternator is the most feasible solution . Rewinding the existing alternator ie one or both rotor (field) and stator windings with a higher gauge would not be practical because of the space limitation even if it is theoretically correct . Then if you increase your field current the existing regulator and the diode bank should be able to handle the extra load. You can go for a smaller (by how much) pulley but the gain would be marginal. Do you have any problem with one of your batteries now?

Edited February 7, 2014 by Rumesh88

[Nishan.dj]

Do you have any problem with one of your batteries now?

Batteries are fine and getting charged without a problem. I am changing AC to dual now and the person who does that says he will test the load and may be needing a higher capacity alternator. However I didn't get it done completely yet and therefore can not do a load test now. Anyway I also feels it may need to have a higher capacity alternator. What he suggest is to re-wind the current one. I need to find possible ways I can do it with lower cost and also has to be durable. Thank you Rumesh88 for the reply but what would you suggest if it will need higher capacity?

[Rumesh88]

OK. If that is the case you have to wait for the completion of your work for a load test get an exact picture. However, if you do not have added electrical loads over and above the original load, a dual AC won't make much of a difference. If the additional requirement is marginal (lets say 1-2 Amp) then what your mechanic suggest would work but considering the reliability required in this type of a vehicle, going for ad hoc measures is not that advisable.

[Nishan.dj]

what your mechanic suggest would work but considering the reliability required in this type of a vehicle, going for ad hoc measures is not that advisable.

You mean re-winding? and yes durability is the top most important.

[Mean Green z28]

I'd upgrade the alternator before I think of re-winding it. There's electronics in there that keep the unit from overcharging your system/etc. and you may mess with that if you only re-wind.

[Sylvi]

Nishan. dj,

First of all finish your all A/C fixing and other additional fittings on your vehicle, test the load. Draw of amperes at low RPM on your vehicle.

Check the alternator tag if it is rated to produce, the draw of your vehicle new load. Then there is nothing for you to worry.

If not producing your required amperes then go in for a used working Alternator with a higher amperage.

If it is not producing correct required amperes at low RPM. Increase the speed of your engine, Test alternator is compensating the current. (Amperes)

Now do the road driving test.

Your vehicle has a Diesel engine. Therefore there it is no problem of power. Remember the full load test (Amperage) must be at slow driving speed.

Not on low gears, must be comfortable driving speed on high gear. Without any discharge amperage, with all your full load including lights.

If the alternator is not producing the required amperage at low driving speed. Then you can change the pulley. to a smaller one.

Rewinding your same alternator.

This can be done. First of all check if the stator winding is connected star or delta. Three windings are connected to Y or Triangle connections.

Y connection means, the six wire ends of the stator windings, Three wires are connected to one and all other three connections are connected to Diode plate.

Triangle (Delta) means Six ends of the three stator windings are connected to be only three ends. That means only three connections are connected to

Diode plate.

Star connected winding will not give more Amperes. Delta connected winding will give more Amperes.

I post the wiring diagram below. Please note if you do a Delta connection on your winding have to use high amperage Diodes to give higher output amperes.

Simplified explanation is that star gives more voltage and delta gives more amps for a given RPM.

Sylvi Wijesinghe.

[Nishan.dj]

Thanks Sylvi for the detailed reply. Still the work is not completed to do the load test. sooner I do it, will post the result here. and of course ask ideas if needed to have more amperage.