140 amp vs 80 amp alternators (2 Viewers)

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I talked to the PO and he said it was a GM alt and that the bracket was custom that he welded up, but it mounts to the factory bracket supposedly. it's dark now but i'll try and get a pic tomorrow @LS1FJ40
 
ok I got complained to e-bay seller about 140 amp alternator so he said he will get me a new one with smaller pulley as replacement, so I got my original and I did ordered smaller pulley - anyone want it?
 
I talked to the PO and he said it was a GM alt and that the bracket was custom that he welded up, but it mounts to the factory bracket supposedly. it's dark now but i'll try and get a pic tomorrow @LS1FJ40
C'mon, where is that picture? I have been researching options for a higher output alternator for the 3fe's.
I noticed that the alternators from the 2005+ V6 Tacoma's are 100amps, which may work.
Then there is the option of Sequoia/Tundra alternators, but I understand that might be a tight squeeze.
Then I had the thought of, "What about a GM alternator?" and search led me to this thread.
I am mainly interested in the dimensions and electrical connectors.

@LS1FJ40 , what have you found out? I know you have been looking into this as well.
 
The stock alt in my '97 makes around 14.8-9V at startup, going down to 14.6-7V after about 15 minutes of driving. Usually by the time I'm getting home 30 min. later it's around 14.2. After an 45 min. to an hour on the road it would be into the high 13's.
I've even seen it hit 15.1V on a few occasions.
 
Have to choose the alternator carefully. Most aftermarket jobs simply have more and tighter windings, which can lead to overheating and early demise. They also don't reach their advertised outputs until the RPMs are way beyond anything a Cruiser is likely to see (though as matt points out above, you can game this by changing the pulley size). Voltage and amp profiles differ widely, and winding type affects this. Looking into this myself and thinking to go with some kind of Toyota stock (or stock-replacement) HD alternator. Delco Remy comes to mind. Still researching. I have been advised by some heavy hitters that, with dual 31s, an alternator "upgrade" is not really needed.
 
Good points from jaymar. Pretty much every alternator I have seen that has been 'upgraded' produce less amperage at idle than the stock items, you need the juice when idling in traffic perhaps with the heater on, HRW, radio, lights etc. Ultimately they burn up and get replaced prematurely, my stock 80 amp was working perfectly when removed after 19 years!

A few years back I went with the Sequoia stock 150 amp, bolted on with a minor adjuster bracket and uses the standard plug. Shedloads of amps/volts at idle but, you will need to up the heavy cable to the battery.

Going bigger is better when using factory parts.

regards

Dave
 
C'mon, where is that picture? I have been researching options for a higher output alternator for the 3fe's.
I noticed that the alternators from the 2005+ V6 Tacoma's are 100amps, which may work.
Then there is the option of Sequoia/Tundra alternators, but I understand that might be a tight squeeze.
Then I had the thought of, "What about a GM alternator?" and search led me to this thread.
I am mainly interested in the dimensions and electrical connectors.

@LS1FJ40 , what have you found out? I know you have been looking into this as well.

I haven't done anything with this yet. Been busy with work. I don't know a ton about electrical so it is going to take me a while to try to figure this out and research it.
 
sorry, I never go the picture that I promised... I will tomorrow.
 
Last spring I ordered a custom built 140 amp alt. When I installed it I had the same exact simptoms you are having. What I found out is that the pulley on the test machine used by the shop that built the alternator is smaller than the pulley on our crank shaft and on top of that our engine idles at a slow 625.
I called them up and here is what there "special problems guru", who happens to be an off roader himself, told me. He said that he can't understand off road guys feeling they need all this amperage capability when the battery will only accept charge at a certain rate anyway and that more reserve capacity found In a dual battery set up is more useful.
I went on line and found two different sites that charted typical loads for those components on our rigs that use electicty. I created a hypothetical situation where I was wheeling at night, lights on in the winter with heater and wipers running and stereo playing. What I came up with was a total load of 62 amps and that included what the engine uses to run. This does not account for a plethora of lights being on all at once or a refrigerator (how much do these really draw anyway) or a laptop or back seat riders playing Xbox or watching DVDs because this stuff won't be going on in my rig. So, I'm sure power needs may vary but 150 amps would be a huge demand.
It is possible to overcome your stock 80 amp alternator but you would need to be running everything at the same time and that never happens. And don't think that there is an alternator out there that will keep up with a winch, this is where two batteries are King.
I put new brushes in my original 1994 alternator, put it on my rig and I have yet to install a second battery and I would wager a bet that I use my winch more than the average Mudder and I have yet to have an issue. However, dual batteries are on my wish list. Cheers
 
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Last spring I ordered a custom built 140 amp alt. When I installed it I had the same exact simptoms you are having. What I found out is that the pulley on the test machine used by the shop that built the alternator is smaller than the pulley on our crank shaft and on top of that our engine idles at a slow 625.
I called them up and here is what there "special problems guru", who happens to be an off roader himself, told me. He said that he can't understand off road guys feeling they need all this amperage capability when the battery will only accept charge at a certain rate anyway and that more reserve capacity found In a dual battery set up is more useful.
I went on line and found two different sites that charted typical loads for those components on our rigs that use electicty. I created a hypothetical situation where I was wheeling at night, lights on in the winter with heater and wipers running and stereo playing. What I came up with was a total load of 62 amps and that included what the engine uses to run. This does not account for a plethora of lights being on all at once or a refrigerator (how much do these really draw anyway) or a laptop or back seat riders playing Xbox or watching DVDs because this stuff won't be going on in my rig. So, I'm sure power needs may vary but 150 amps would be a huge demand.
It is possible to overcome your stock 80 amp alternator but you would need to be running everything at the same time and that never happens. And don't think that there is an alternator out there that will keep up with a winch, this is where two batteries are King.
I put new brushes in my original 1994 alternator, put it on my rig and I have yet to install a second battery and I would wager a bet that I use my winch more than the average Mudder and I have yet to have an issue. However, dual batteries are on my wish list. Cheers

Still running the stock alternator on mine. :) If you're overlanding though, you want a second battery.
 
I have a 140 amp alt and my rig was idling for about an hour and I went to use my winch and the power drain killed my motor. Had to get a jumpstart back... One of the several lessons I learned this weekend. So that being said, I WILL be getting a dual battery setup asap. and replacing my parts store cheapo battery with a good one. or two.

I will also get that pic today at lunch.
 
I have a 140 amp alt and my rig was idling for about an hour and I went to use my winch and the power drain killed my motor. Had to get a jumpstart back... One of the several lessons I learned this weekend. So that being said, I WILL be getting a dual battery setup asap. and replacing my parts store cheapo battery with a good one. or two.

I will also get that pic today at lunch.

One word: Odyssey.
 
The consensus is the Interstate batteries are excellent bang for the buck. When I finally get around to installing my dual battery set up and Renogy solar panels I will be replacing my batteries with two from Interstate.
 
The consensus is the Interstate batteries are excellent bang for the buck. When I finally get around to installing my dual battery set up and Renogy solar panels I will be replacing my batteries with two from Interstate.

Good brand; my Cruiser came with a group 24 that lasted 6 years. I've read about Odysseys going 10-13, but they are costly.
 
Amp are amps, if your winch pulls say 150 amps then even with the engine running say a 150 amp alternator the battery will eventually give up in fact, 2, or even 10 batteries will give up eventually, it will simply take longer to happen. This is about demand versus available supply, even holding the revolutions at say 2,500 RPM (most alternators are 'all in' by now), the battery will still go flat.

So to clarify, if you have a genuine 150 amp alternator and you are turning the revolutions and you pull 150 amps via a winch, you will eventually flatten the battery/s. This is because of the draw of other loads, fuel pump, ignition system and so on.

Taking rblain82's example, if his engine is idling for an hour and he has typical electrical loads his battery should be pretty much fully charged, this would be the case with a normal 80 amp alternator, at idle these can easily supply 30 plus amps, we already know the stock alternator can supply enough amperage to run the fuel pump, ignition radio and say the AC. He applies the load from the winch (let us assume 150 amps), his battery should supply that load easily if it is good condition, that draw is up there with the amount needed to start the engine, but his engine cut out. This in theory should not have happened but it did so why?

Conclusion is one of the following:

His alternator supplies less than the idle load on the battery (fuel pump, ignition for example), this indicates the alternator may be faulty or, it is a modified version that now offers less amperage at idle traded for higher amperage at elevated RPM. Also the voltage regulator must be around 14.4 volts, low volts means nothing goes in the battery.

His battery is not accepting the charge due to a fault, the activation of the winch pulled all the available amperage from the alternator, leaving nothing for the components needed to run the engine.

His battery has a faulty cell and is unable to supply the 150 amps required by the winch, which exceeds the 140 amps which the alternator would definitely not be supplying at idle, unlikely to be the battery if the car started fine before winching commenced.

The wiring to the winch (or the winch motor itself) has a dead short, a 150 amp short would probably kill any engine at idle.

Next, the above thought that there is no need for a bigger alternator and two batteries are king, this is also wrong. Agree the battery will only absorb what it can handle but, what if the amps it can absorb are not there in the first place?

'baldilocks' comments demonstrates this possibility very clearly.

You have just drawn say around 150 amps by starting your engine, how long before the battery is back to the 'pre cranking' level? Ten minutes, perhaps 20? But he started his car at night, it was cold, the heater blower is on, as are the lights and HRW, oh and it is raining, sounds like a typical night in the UK!

His hypothetical set up drawing 62 amps is indeed correct except for one thing, it did not allow for an amount to charge the battery, it is going to take at least 15 - 20 minutes to put back that charge! The reason? Even if the stock 80 amp was brand new he is left with a mere 18 amps to charge his battery, and this assumes he kept his engine RPM's at around 2,500, and the battery is new as well, the moment he eases off the gas his battery will be supplying at least half of that 62 amps as the alternator will simply not be turning fast enough. He drives the kids to McDonalds three miles away (5 minutes), parks up and drives them back after a great meal (well alright it is only Macy Dees). The battery did not get fully charged on the way there OR back, in the morning he is about to start the engine with a battery that is not fully charged but, there is sufficient capacity and the stock alternator will 'offer' the battery perhaps 40 amps and the battery will take it...............er no. There is now an internal resistance of about 10% - 15% that needs to be overcome so 40 becomes 44 +, but the radio is on along with the heater and it's raining, the alternator has no more to offer, again the battery is bearing the brunt of the workload........unless his alternator was capable of say and extra 20 or 30 amps that the battery was looking for.

This scenario can only go on for so long, batteries do not like being half charged, the battery life will be shortened, how long will be dictated by the quality and type of battery being used, or how long before you go for a proper drive of about an hour or so to fully charge the battery. And we are going to fit a winch anyway! Here the second battery is a good idea but, if your winching is done with a stock alternator then ultimately both batteries lives will be shortened. None of this set in stone as there are many variables, your stock radio has been replaced by an all singing all dancing ear blasting amp eating mean machine, there was a serious traffic jam on the way to work, the engine was idling most of the way to the aforementioned burger shop, your drive to work takes only 10 minutes on the motorway, high speed but too short a duration.

Fit two decent batteries and a genuine high output alternator and not some Mickey Mouse upgrade and be done with it, demand MUST be met by supply or something has to give eventually.

regards

Dave
 
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Before you drop the coin on the big Grp 31 Odyssey, realize it takes a weird charge profile to live a normal life. How many of our alternators will charge at 40 amps up to 14.8 volts? None. It will basically force you to buy an expensive charger and plug your truck in every night. To me, it makes far more sense to just buy a decent conventional battery. No strange charging profile, no special needs, you can add water if you need to, and for the price of 1 AGM battery you can buy 3 conventional batteries.

Interstate is now made by Johnson Controls. Interstate does not make batteries. They market batteries. I don't know if that is good or bad, but the exact same batteries are available at Costco.

I think it is best to look at batteries as a consumable item, and just 1 more thing to replace at a scheduled interval. Conventional batteries with a bit of care go 4-5 years. AGM batteries go 4-5 years too. If you have special mounting needs, like placing it on it's side, by all means get an AGM battery. But if you don't, you're just paying more and not getting more.

We had some of this same discussion in the Sequoia alternator thread, but if you don't have a need to generate 150 amps, why would you bother? Batteries can only accept charge so fast. So a bigger alternator will not recharge them faster. Plus, their last 10% of charge is accepted VERY slowly-just a few amps, so no matter how much alternator you have, it will not matter. The only reason you might need a bigger alternator is if you have a large continuous need-like giant lights, life support equipment, or huge powerful radios. That's why ambulances have upgraded alternators.

The 80 has a 90 amp alternator stock. Someone added up and measured the worst case scenario in an 80 and came up with 57 amps continuous. And that's literally every electrical item turned on high. So you can see why a 90 amp alternator is actually plenty, and even has a 40% reserve capacity already.

Regarding Dave 2000's comment-He is confusing amps with power. Assuming starting your engine uses 150 amps for 5 seconds. That's actually 0.21 amp-hours. Your average car battery has about a 75 amphour capacity. So to replace the cranking power back to the battery is nearly instantaneous. Even if you have a charging current of just 1 amp, all the power would be replaced in 12 minutes, at 10 amps(more realistic), just over 1 minute. The point is, the power to start your car is trivial interms of the capacity of the battery. It takes a high current though, but for just a few seconds.
 
Very interesting. Thanks for the info guys. I have been thinking of this after a quad projector retrofit, possible install of a LED bar and running a fridge. Sounds like with a factory alternator in good condition I have nothing to worry about.
 
Before you drop the coin on the big Grp 31 Odyssey, realize it takes a weird charge profile to live a normal life. How many of our alternators will charge at 40 amps up to 14.8 volts? None. It will basically force you to buy an expensive charger and plug your truck in every night. To me, it makes far more sense to just buy a decent conventional battery. No strange charging profile, no special needs, you can add water if you need to, and for the price of 1 AGM battery you can buy 3 conventional batteries.



Regarding Dave 2000's comment-He is confusing amps with power. Assuming starting your engine uses 150 amps for 5 seconds. That's actually 0.21 amp-hours. Your average car battery has about a 75 amphour capacity. So to replace the cranking power back to the battery is nearly instantaneous. Even if you have a charging current of just 1 amp, all the power would be replaced in 12 minutes, at 10 amps(more realistic), just over 1 minute. The point is, the power to start your car is trivial interms of the capacity of the battery. It takes a high current though, but for just a few seconds.

Agree with the first paragraph, my recent battery purchases prove that to be very valid. Re the next paragraph I do not entirely agree.

Your figures are assuming 100% efficiency and in the real world that just does not happen. A battery is never at 100% charge to start with, there will be natural losses in efficiency from the date of manufacture,t the battery would have stood a period of time with parasitic losses, these range from, ageing, cold, alarm systems, and even damp on the surface of the battery itself. Also batteries will accept a fair charge until the gap from nearly charged to a 'near' full charge closes, then the charge rate will fall even lower, so batteries IME rarely reach a fully charged state in normal use. And to use the 75 amp hour battery analogy, just how many times can you pull 150 amps for 5 seconds from a 75 amp hour battery?

Start run for 1 minute, switch off and restart, run for 1 minute, switch off and restart, do you think this would work or do you think the battery would start to fail after about 60 starts? The theory is agreeable but given the variables I would guess the battery would be on it's knees within an hour?

regards

Dave
 
Is there a way to check actual amp output from battery and alt? How can I test all these theories?

I'm not sure my battery is good. It was installed by the PO.
 

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