Higher Amp alternator for 1995 Defender 300tdi

[winthorp_defender]

First post here so I hope I am not posting something which has been discussed 100 times already.
I bought a 1995 130 Defender 300 tdi (dual cab) a couple of months ago. The car is given its age in decent condition. I have the typical rust on the inner door frame some issues with the blinker and lights as well as leaking issues (door seals as well as some seals around the firewall and the rear.
The car was once a celebrity in the 4wd community and the first owner appeared in some magazines as well as on some 4wd shows (the guy is called Jamie and he has a shop here in Queensland).

JTS Offroad TV Custom Defender walk through - YouTube (https://youtu.be/mPOllUn-xKw)

The car has a pretty well set up electric system (although it is not exactly the one as in the video but installed behind the rear seat together with a compressor). I am still trying to figure out the exact configuration but what I can see is, that I have a dual battery. One is connected to the Alternator (main battery) and the other is connected to an inverter which I can charge when I am at home or potentially thru a solar panel (still to figure out). They do not see to be connected thru an isolator. I ran the car and used a voltage meter and only one of the batteries got charged.
The 2nd battery also operates the winch. Since I t is not charged thru he alternator and I might plan to also connect my off road trailer with its own dual battery and solar system and the fact that I still seem to have the original 65 AMP alternator installed I was planning to upgrade. I read in several posts that the 100 Amp form the Discovery is an option.
However given the setup I have I was thinking of a more powerful alternator in the 150 to 200 AMP range. I would then install an isolator and I can charge both batteries with the alternator. I also understand that this might required some re-wiring of the charging cables which I am willing to do.

I just upgraded the alternator on my 19982 Merc 300 Diesel from 55 to 115 amp. I used an 1990's Saab alternator for that since these have a similar spec, just a bit bigger. It also required thicker cables due to the additional load.

Does anyone know which alternator (even non Land Rover types) would provide the amp-age as well as would fit in the provided brackets? Alternatively I could fabricate something and fit a alternator which at least partially would fit.

Thanks for any input.

[shack]

Pretty sure a Discovery 1 alternator will fit, and I think they are 120amp.

The original defender alternator is a pretty poor setup internally.

[AK83]

Disco alternator is 100amp.
Normally is enough, unless you run an absolute ton of electrical gear whilst driving, but this would be quite extreme.

Alternatively, if you expect to run the winch a lot, then a higher rated alternator would be needed too.

Back in the day, in my early RRC, which originally had a 45A alternator, and I had lots of lighting power going(all up near at 500w in full use), peltier type fridge(remember, this was 'back in the day'!), electric fans(at 40amps) and at night with all the loads running I could see that the ammeter would be showing discharging, so I'd have to turn (say) the spotties off for a bit till charge came back, or electric cooling fans turned off .. or something like that.
Ran this way for quite a while .. well for as long as the yearly dead of a thousand Lucases would allow .. the pathetic Lucas alternators(or parts) would simply quit pretty much at the 12 month stage of their life.

So did a back of the envelope calculation, when the final time came to rectify the dead alternator, and found that 80 amps would be enough to run all the electric loads(plus obviously the v8s ignition system) and located a suitable alternator in that range.
Had an electrician re-jig the plug end for the modded alternator and never looked back. As I recall it was a Bosch unit out of a 260Z(Nissan), and other than the connections needing modding too, fit pretty much straight in.

Nowadays with LED driving lights and all this more modern somewhat electrically efficient stuff, on old tech system like the 300 tdi, which requires, pretty much, zero electrical input ... you don't need a super powerful alternator.
(except as noted if you plan to run the winch a lot).

100 amps should be fine. If you do this change, make sure that you know the size of your current pulley(on the alternator). There are two sizes 49mm and 62mm, and this affects belt size and, if you have one, the Tacho reading.

It's unusual not to run an aux battery through a simple (and generally cheap) isolator. Have you traced the leads from the aux battery fully. Have seen some very nasty electrical installs in my time, so you can never be too sure what a previous 'modder' has done.

[p38arover]

Back in the day, in my early RRC, which originally had a 45A alternator,

Looxury! My 1971 Hillman Hunter had a 25A alternator!

[TonyC]

Looxury! My 1971 Hillman Hunter had a 25A alternator!

If we're having a race to the bottom!

My Hafinger has 240 watt Dynastart, a combined generator starter motor.

I put a set of driving lights on it once, and ended up with a flat battery ☹️

I have done a few trips with the fridge running off the battery and that was OK

So, anyone have a smaller alternator or generator? Series 1 perhaps.

Apologies to the OP for the off topic.

Tony

[winthorp_defender]

Disco alternator is 100amp.
Normally is enough, unless you run an absolute ton of electrical gear whilst driving, but this would be quite extreme.

Alternatively, if you expect to run the winch a lot, then a higher rated alternator would be needed too.

Back in the day, in my early RRC, which originally had a 45A alternator, and I had lots of lighting power going(all up near at 500w in full use), peltier type fridge(remember, this was 'back in the day'!), electric fans(at 40amps) and at night with all the loads running I could see that the ammeter would be showing discharging, so I'd have to turn (say) the spotties off for a bit till charge came back, or electric cooling fans turned off .. or something like that.
Ran this way for quite a while .. well for as long as the yearly dead of a thousand Lucases would allow .. the pathetic Lucas alternators(or parts) would simply quit pretty much at the 12 month stage of their life.

So did a back of the envelope calculation, when the final time came to rectify the dead alternator, and found that 80 amps would be enough to run all the electric loads(plus obviously the v8s ignition system) and located a suitable alternator in that range.
Had an electrician re-jig the plug end for the modded alternator and never looked back. As I recall it was a Bosch unit out of a 260Z(Nissan), and other than the connections needing modding too, fit pretty much straight in.

Nowadays with LED driving lights and all this more modern somewhat electrically efficient stuff, on old tech system like the 300 tdi, which requires, pretty much, zero electrical input ... you don't need a super powerful alternator.
(except as noted if you plan to run the winch a lot).

100 amps should be fine. If you do this change, make sure that you know the size of your current pulley(on the alternator). There are two sizes 49mm and 62mm, and this affects belt size and, if you have one, the Tacho reading.

It's unusual not to run an aux battery through a simple (and generally cheap) isolator. Have you traced the leads from the aux battery fully. Have seen some very nasty electrical installs in my time, so you can never be too sure what a previous 'modder' has done.

Thanks for the response. As mentioned i am still trying to figure out the exact set up. I am actually planning to meet the guy who was building this rig once it is re-registered and roadworthy. He lives just about an hour from where i live. I assume he has set the car up for a particular purpose and I am not sure if this is exact the same purpose I what to use the car for.
I certainly plan to use the winch when I am out on the tracks. Not planning to do just touring but wanted to get the rig out to the various places where I am living (around Glasshouse Mountains). So it would be not bad having the second battery charged as well. I assume he was using the second battery primarily for the fridge and some other parts he had in the back. I also assume he made shorter weekend trips rather than being on long 2 or 3 weeks trips since he had to run a business. I have also an offroad trailer so we are planning to bring for the longer trips around Queensland. I will run at least 1 or 2 fridges in he back and charge my batteries in the trailer too if there is no sun available.

So back to my original question, is there alternator with the form factor of the Defender or Discovery which provides 150+ Amps?

[TonyC]

Thanks for the response. As mentioned i am still trying to figure out the exact set up. I am actually planning to meet the guy who was building this rig once it is re-registered and roadworthy. He lives just about an hour from where i live. I assume he has set the car up for a particular purpose and I am not sure if this is exact the same purpose I what to use the car for.
I certainly plan to use the winch when I am out on the tracks. Not planning to do just touring but wanted to get the rig out to the various places where I am living (around Glasshouse Mountains). So it would be not bad having the second battery charged as well. I assume he was using the second battery primarily for the fridge and some other parts he had in the back. I also assume he made shorter weekend trips rather than being on long 2 or 3 weeks trips since he had to run a business. I have also an offroad trailer so we are planning to bring for the longer trips around Queensland. I will run at least 1 or 2 fridges in he back and charge my batteries in the trailer too if there is no sun available.

So back to my original question, is there alternator with the form factor of the Defender or Discovery which provides 150+ Amps?

At the bottom of each page there are two Google search boxes, one searches the whole Web, the other searches just AURLO.

Here are two threads on alternatives.

Defender Alternator Options (https://www.aulro.com/afvb/90-110-130-defender-county/37655-defender-alternator-options.html)

Disco1 alternator no charge? (https://www.aulro.com/afvb/technical-chatter/67247-disco1-alternator-no-charge.html)

Tony

[AK83]

.....

So back to my original question, is there alternator with the form factor of the Defender or Discovery which provides 150+ Amps?

I'd still suggest that a 100A Disco type alt would be sufficient for the vast majority of your needs.
What size battery do you have in the car?
Do you have plans to mod the set up at all(would be recommended), and are you able to do all or most of the work yourself(or do you rely on professionals).

Pretty much all the work is easy stuff to do yourself.

I personally don't have a trailer, ie. no large battery setup to charge back there, but both myself and bro have a 100Ah battery pack that we share when needed(so kind of similar ... ish).
Never had issue with keeping that 100ah battery topped up, and I personally don't have any solar equipment myself, I just deplete batteries and manage them that way.
Bro has panels and blankets to top up the batteries.

I have a 300tdi(D1) and he has(shared) TD5 D2. D2 has 120A alternator. I have used it yet for extended trips(just my D1).

Compressor fridges use a lot less power than peltier type(which consume power all the time) and still have never killed or fully drained either my aux battery, nor the third power bank.
The power bank is just a battery box, and we chucked in a 70ZZ 100Ah battery, and damned it's heavy! .. if it ever dies, we'll probably replace it with a lithium jobbie.

But, not knowing how the 130 is setup, but assuming you can and will set it up to your preferred use type, with some solar panels, 100A should be heaps from the car. The difficult choice would be which isolator would best suit your needs.
Most modern ones will quite effectively charge car main, any aux in the car and also trailer batteries whilst on a drive.
Then when parked up, and car and trailer still connected, the solar would then simply keep the trailer, and both car main and aux topped up. Obviously if you unhook trailer, solar will not charge the car batteries.

EDIT: forgot to add, that if I get a chance too at some point I'll see if a D2(v8) alternator is an easy mod to fit to a 300tdi too. I have both and will fish them out of the junk pile and check.

[winthorp_defender]

I'd still suggest that a 100A Disco type alt would be sufficient for the vast majority of your needs.
What size battery do you have in the car?
Do you have plans to mod the set up at all(would be recommended), and are you able to do all or most of the work yourself(or do you rely on professionals).

Pretty much all the work is easy stuff to do yourself.

I personally don't have a trailer, ie. no large battery setup to charge back there, but both myself and bro have a 100Ah battery pack that we share when needed(so kind of similar ... ish).
Never had issue with keeping that 100ah battery topped up, and I personally don't have any solar equipment myself, I just deplete batteries and manage them that way.
Bro has panels and blankets to top up the batteries.

I have a 300tdi(D1) and he has(shared) TD5 D2. D2 has 120A alternator. I have used it yet for extended trips(just my D1).

Compressor fridges use a lot less power than peltier type(which consume power all the time) and still have never killed or fully drained either my aux battery, nor the third power bank.
The power bank is just a battery box, and we chucked in a 70ZZ 100Ah battery, and damned it's heavy! .. if it ever dies, we'll probably replace it with a lithium jobbie.

But, not knowing how the 130 is setup, but assuming you can and will set it up to your preferred use type, with some solar panels, 100A should be heaps from the car. The difficult choice would be which isolator would best suit your needs.
Most modern ones will quite effectively charge car main, any aux in the car and also trailer batteries whilst on a drive.
Then when parked up, and car and trailer still connected, the solar would then simply keep the trailer, and both car main and aux topped up. Obviously if you unhook trailer, solar will not charge the car batteries.

EDIT: forgot to add, that if I get a chance too at some point I'll see if a D2(v8) alternator is an easy mod to fit to a 300tdi too. I have both and will fish them out of the junk pile and check.

Thanks a lot for the detailed reply. The D2 V8 Alternator seem to be what I was looking for. I am not worried to modify the set up a bit if I have to. And yes, I am planning to do everything myself. I have installed an isolator on my previous car (Jeep Grand Cherokee from 2001) along with a lot of other mods.

As mentioned I will visit the original owner of the car and ask him about the setup this should clarify things hopefully. I have Solar panel installed on the trailer so can keep the batteries charged. They are rather new gel batteries and hold the voltage quite well. Once in a while I drain them and recharge them to keep them healthy. I cant keep them on the solar panel all the time since it is too powerful. I would need to change to smaller ones to trickle feed and just top up to keep the voltage high.

The aux. battery in the Defender (the one not connected to the alternator) seem to be ok, although it is discharging itself over time so I have to watch this closely. The main battery seem to be on its way out since it drops voltage quite fast even so I am not moving the car at all. Will get a larger one with a bit more cca (have now one with 770 cca and it is about 60% of the size of the aux battery).

If I am upgrading to a larger alternator a larger battery with more cca should be no problem. What I can see is that I need to re-wire the setup. The current cables are 8 gauge cables only (if even that much) if I am running 120 or 150 Amps I need to use at least 2 gauge cables esp. what I am planning to run on that stuff can get hot especially in the summer. I almost burned my Grand Cherokee down when I ran only a 4 or 8 gauge cable from the main battery to the trailer on a 136 amp alternator (cant remember the exact size, since it was a quick not well thought thru decision, but it was literally melting the plastic off the cable and it shorted out on some metal on the chassis). So I learned my lesson here.

I believe that the car has all the required setup already I just need to find the right connector for the right in or output. There are at least 10 different in and outlets on this car and I just did not have the time to figure out which one would be what.

Do you happen to have a link what kind of mods I need to do, to be able to fit the D2 alternator onto the Defender?

[drivesafe]

Hi Winthrop and first off, welcome to the forum.

Next and most importantly, there is no way on earth that cabling should get to a point where it got so hot that the insulation melted.

The is an absolute No-No but is all to commonplace.

The only reason cabling could get that hot is because it was either protected incorrectly or had no protection at all.

The most common reason for fires in cabling is because the fuse or circuit breaker used to SUPPOSEDLY protect the cabling was way to big.

I could not count the amount of times I have seen fire damage in engine bays because auto electricians had run 6mm AUTO cabling ( 4.5mm2 ) to a caravan plug at the rear of the vehicle, for brakes and for a dual battery setup and they have used a 50 auto resetting circuit breaker to “protect” the cabling.

6mm AUTO cabling ( 4.5mm2 ) often has 50 amps marked on the label of the roll of cable, and I have no idea why this is done.

6mm AUTO cabling ( 4.5mm2 ) has a MAXIMUM CONTINUOUS current load rating of just 35 amps and the largest SAFE protection rating for a fuse or circuit breaker to protect this size cabling should be no more than 25 amps.

But auto elect continually fit 50 amp circuit breakers, with the end result being a fire.


Now for some suggestions for your rewiring.

First and foremost, remove the winch cabling from your auxiliary battery and connect it to your cranking battery. THATS WHERE IT BELONGS.

For a winch to operate at its best and not to heat up to quickly, you need the shortest cable run between it and the alternator, but you need this cable run to come via the cranking battery, to use the battery as a spike suppressor to protect the alternator.

Next, if you can fit the auxiliary battery in the battery box under the passenger seat, next to the cranking battery, I would do so as this will help to reduce the amount of voltage drop that occurs while using the winch.

It is not imperative that the auxiliary battery be moved to the battery box, but it will improve your winching operation.

Regardless of where you have the auxiliary battery, you need to run 3B&S cabling ( 25mm2 ) between you cranking battery and you auxiliary battery and this is both for the Positive ( + ) and Negative ( - ) cables.

Again regardless of where the two batteries are located, link the 3B&S Negative ( - ) cable between the Negative ( - ) terminals of each battery.

If the two batteries are in the battery box, then link the 3B&S Positive ( + ) cable between the Positive ( + ) terminals of each battery, via an isolator, and with both batteries in the battery box, no fuse or circuit breaker is needed.

If the auxiliary battery is located somewhere else in the vehicle, then as 3B&S cabling ( 25mm2 ) has a maximum safe continuous current rating of 200 amps, you MUST fit a fuse or circuit breaker of no more than 150 amps as close as possible to the Positive ( + ) terminal of each battery.

Again this Positive ( + ) should be run via an isolator.

NOTE, if you use anything other than a Traxide isolator, it MUST BE located as close as practical to the cranking battery. A Traxide isolator can be located anywhere between the two batteries, even next to the auxiliary battery when it is in the rear of the vehicle.

For the cabling running to your caravan or camper trailer, run 6B&S ( 13.5mm2 ) twin cabling from the auxiliary battery, regardless of where it is located, to an 50 amp Anderson plug at the rear of the vehicle.

As 6B&S ( 13.5mm2 ) has a maximum safe continuous current rating of 105 amps, you MUST fit a fuse or circuit breaker of no more than 80 amps, as close as possible to the Positive ( + ) terminal of auxiliary battery in the tow vehicle and Positive ( + ) terminal of house battery in the in the caravan or camper trailer.

ALSO NOTE, when I refer to Anderson plugs, I mean the genuine Anderson plugs, not any of the copies. Genuine Anderson plugs are actually rated at a continuous current rating of 95 amps at 12v.

[drivesafe]

I cant keep them on the solar panel all the time since it is too powerful. I would need to change to smaller ones to trickle feed and just top up to keep the voltage high.
If you have a good quality solar regulator, the size of the solar panels is irrelevant.

A good solar regulator will keep your batteries in good nick because once the batteries are fully charged, the regulator will only apply a FLOAT charge, which will maintain the batteries in a fully charged state without over charging them.