Disadvantages of a Generator

[101RRS]

My series 1 is still running a generator but has been converted to negative earth. The charging system seems to be working fine and the engine will run fine without the battery.

For a car of its vintage that is not going to have to support high electrical loads what are the disadvantages of staying with the generator over converting to an alternator.

Thanks

Garry

[LandyAndy]

I had a Series 2 with a generator.
It proved to be a real pain when out shooting,the battery will not recieve the full charge at trundle around the paddock speeds.
By the end of the nite the spotlight got quite dim and you didnt dare stall the old beast as a push start was needed.
I fitted an alternator and all was well.
Andrew

[Michael2]

keep it original

[Blknight.aus]

no real disadvantage if you have a good battery, If you consistantly trundle around simply change the pully for a better ratio...

the biggest one i know of is the requirement to clean the armature contacts more often than you do an alternator.

[101RRS]

I had a Series 2 with a generator.
It proved to be a real pain when out shooting,the battery will not recieve the full charge at trundle around the paddock speeds.
By the end of the nite the spotlight got quite dim and you didnt dare stall the old beast as a push start was needed.
I fitted an alternator and all was well.
Andrew

But even when the battery is flat, you can still push start a car with a generator but not one with alternator as battery power is needed to energise the coils in the alternator. At least a generator does not need this and will generate enough power to start an engine when pushed start.

I do however know what u mean with high power needs with low engine speed.

Garry

[EchiDna]

But even when the battery is flat, you can still push start a car with a generator but not one with alternator as battery power is needed to energise the coils in the alternator. At least a generator does not need this and will generate enough power to start an engine when pushed start.

I do however know what u mean with high power needs with low engine speed.

Garry

? I've push started alternator equipt cars on multiple occasions due to dead batteries...??

[Blknight.aus]

nahh, the battery would have had at least 3-4 volts left in it which is just enoug h to fire the coil and excite the alternator...

simulate a dead flat battery, remove the earth lead and see which on you can get to start.

[kaa45]

Mine will push start with a dead battery :D and it's got an alternator :angel:

[EchiDna]

nahh, the battery would have had at least 3-4 volts left in it which is just enoug h to fire the coil and excite the alternator...

simulate a dead flat battery, remove the earth lead and see which on you can get to start.

is it really posible to get less than 3-4 volts coming out of a battery? even with a failed cell I would think it will typically have this amount available. Of course with no battery present at all, I get the point that a generator based vehicle can do it, but if there is a battery and I was in that situation I'd be digging out a wiper motor and charging up the battery with that jury rigged somehow :)

[101RRS]

I have had a couple of occasions when I have left things on and the battery has gone completely dead where I have not been able to push start a car with an alternator - the first time was actually with a BMW bike.

If there is not enough energy in the battery to excite the alternator coils then when you push start the alternator will not push out any power to provide power to the electrics in a petrol engine - an old diesel is different.

Gazzz

[Blknight.aus]

is it really posible to get less than 3-4 volts coming out of a battery? even with a failed cell I would think it will typically have this amount available. Of course with no battery present at all, I get the point that a generator based vehicle can do it, but if there is a battery and I was in that situation I'd be digging out a wiper motor and charging up the battery with that jury rigged somehow :)



lowest voltage Ive ever seen on a 12v battey was .1v it took a charge and held it for about half an hour but that was it....

get an old battery and hook up a light to it and leave it there see what happens.

[JDNSW]

1. Dead flat batteries - yes, if you go away for a week leaving the lights on you will have a DEAD flat battery (don't ask!). ALso, last month the battery in the County failed with an apparent internal short reduciing the voltage to 1.5v.

2. Drawback of a generator. If you do not have any significant extra load, the one real drawback of the generator on these vehicles is that the rear bush needs regular oiling, and if neglected, particularly in dusty conditions, this will fail, allowing the armature to pole. I fitted an alternator to my 2a solely for this reason, after three generators. I never had any problems with lack of charge, but I do little night driving in it. Generally the only time you will suffer from lack of charge is if doing mostly night driving and a lot of it at low engine revs, such as in traffic, or as mentioned, when spotlighting.

In a Series 1 I would keep it original. There will be more maintenance than with an alternator, but you probably won't be doing high mileage anyway.
Do NOT fit a smaller pulley to get charging at lower rpm - the pulley size is chosen to safeguard the armature from throwing the windings at high rpm, and although there is a safety margin, I even using the whole safety marging will give little improvement, to get a worthwhile improvement will mean going beyond the safety margin, and although you may tell yourself you are never going to over-rev the engine, it will only take a fraction of a second, for example if the throttle sticks or it jumps out of gear, to destroy the generator. Because in an alternator the winding on the armature is cirrcumferential, this is not a problem with them.

John

[Graz]

My series 1 is still running a generator but has been converted to negative earth. The charging system seems to be working fine and the engine will run fine without the battery.

For a car of its vintage that is not going to have to support high electrical loads what are the disadvantages of staying with the generator over converting to an alternator.

Thanks

Garry

If it ain't broken - don't fix it;)

[vnx205]

But even when the battery is flat, you can still push start a car with a generator but not one with alternator as battery power is needed to energise the coils in the alternator. Garry
After leaving my headlights on for about 15 hours, my car battery was pretty flat. I used jumper leads to start it and then drove home about 50 km. I tried to start the car a few minutes later and the battery was still dead flat.
I jump started again and drove another couple of km and found that the battery had begun to recover.
I always assumed that was because during the 50km trip home the battery was so flat that the alternator didn"t charge at all. The second jump start then created just enough current to get the alternator working.
I think that is an example of an alternator not charging a dead flat battery.

[chazza]

Keep it original and if it does lose charge you can always use the starting handle to get the engine running.:D Who wants to push a Land-Rover anyway?:(

Cheers Chazza