Alternator upgrade - done! (1 Viewer)

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FrazzledHunter said:
My understanding of their explanation is that the windings must dissipate heat under load anyway.
But if you have the perfect storm of high load and low RPM's it means the heat can't be removed fast enough.
They mentioned an alternator can actually catch fire.
Click to expand...
Yeah that's actually a common problem when trying to charge lithium batteries off a vehicle alternator. Lithium has almost no internal resistance (at least until you get up to the ~90% float level), so if you have a 100A lithium battery which is nearly empty, it'll cause the alternator to run at full tilt for an extended amount of time, which can cause it to overheat, especially when sitting idle. I've wondered if a water cooled alternator like they sell down under would help in that case.
 
Our fire trucks see enormous electrical loads (six huge batteries, just in case) but don’t use water cooling for the alternators.. I was thinking that had a lot to do with sealing the unit from contaminants..

They are brushless though, if I remember correctly. Maybe that impacts heat management.
 
linuxgod said:
Yeah that's actually a common problem when trying to charge lithium batteries off a vehicle alternator. Lithium has almost no internal resistance (at least until you get up to the ~90% float level), so if you have a 100A lithium battery which is nearly empty, it'll cause the alternator to run at full tilt for an extended amount of time, which can cause it to overheat, especially when sitting idle. I've wondered if a water cooled alternator like they sell down under would help in that case.
Click to expand...
So thinking about heat and low RPM high power scenarios I looked into water-cooled alternators. I reached out to
Rapid Power. They replied they didn't have anything for the 200 series.
Rapid Power Alternators - Rapid Power - https://rapidpower.com.au/rapid-power/

I looked at other brands but gave up.
One thing I noticed was that the water cooled units had lower power output. I am assuming it's because cooling internals take up room.
So:
  • Get a water-cooled alternator with lower amperage but it might not overheat at low RPM plus is sealed against the elements.
  • Get a big honkin' alternator geared to spin faster and supply power at lower RPM's so it doesn't overheat in the first place
  • And so on...
Thinking about alternators can make your head explode.:bang:
 
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bloc said:
Our fire trucks see enormous electrical loads (six huge batteries, just in case) but don’t use water cooling for the alternators.. I was thinking that had a lot to do with sealing the unit from contaminants..

They are brushless though, if I remember correctly. Maybe that impacts heat management.
Click to expand...

I'm sure if they are designed for the load it's not a problem to handle hundreds or thousands of amps without burning out. OTOH normal automotive alternators will let their magic smoke out under continuous load. The DIY solar forum has many lengthy discussions

diysolarforum.com

LiFePO4 and auto alternator concerns...

Greetings. I am planning on replacing the 100 amp hr AGM house battery in my 2000 VW camper. I have a single remaining concern with the variety of Lithium batteries that advertise Plug and Play status. Because the BMS in a good lithium battery will shut the battery off when fully charged...
diysolarforum.com diysolarforum.com

The magic smoke gets released just after the 4 minute mark...

 
Water cooling is not necessarily an advantage for cooling as it can't touch all parts, especially the rotor. So it makes sense these are more for contamination resistance at some trade for output.
 
linuxgod said:
I'm sure if they are designed for the load it's not a problem to handle hundreds or thousands of amps without burning out. OTOH normal automotive alternators will let their magic smoke out under continuous load. The DIY solar forum has many lengthy discussions

diysolarforum.com

LiFePO4 and auto alternator concerns...

Greetings. I am planning on replacing the 100 amp hr AGM house battery in my 2000 VW camper. I have a single remaining concern with the variety of Lithium batteries that advertise Plug and Play status. Because the BMS in a good lithium battery will shut the battery off when fully charged...
diysolarforum.com diysolarforum.com

The magic smoke gets released just after the 4 minute mark...

Click to expand...

I watched that video a while back. It's a very scary video.:cautious:
 
TeCKis300 said:
Great info!

I'm still pretty keen on possibly overdriving the stock alternator as a poor mans upgrade. Or mitigation against too much idle load/heat. In the teardown of my 169k mile alternator, the brushes had plenty of life left, commutator was clean, bearings smooth. Probably failed regulator or windings due to loads overtime. I don't believe I need more peak amp output, rather more output support at idle including cooling.

With a stock 2.5" pulley, a 2.25" would be a 11% overdrive, 2" 25% overdrive.
At worse case scenario idle 500 rpm, 11% overdrive would be 555rpm, 25% is 625rpm.
Nominal idle 700 rpm, 11% is 777rpm, 25% is 875 rpm
Engine redline at 6k rpm with stock 3:1 pulley has alternator at 18k rpm. 11% is 20k rpm. 25% is 22.5k rpm.

Looking at the typical alternator output curve, even incremental rpm overdrives can greatly increase performance at idle. This graph also reminds me I'm often idling in the desert temps where underhood heat isn't helping.

Some eyeballing of nominal outputs of a typical 180A alternator with different pulleys
@500rpm stock 2.5" pulley - 28A, 2.25" - 32A, 2" - 45A.
@700rpm stock 2.5" pulley - 90A, 2.25" - 108A, 2" - 135A.

I'm really liking the idea of a 2.25' pulley. I do spend quite a bit of time in the upper RPM bands when towing so this is also trying to respect durability there. Now to source one and a shorter belt.

View attachment 3519080
Click to expand...
100% agree with this. A simple pully/belt upgrade will probably take 90% of overland builds out of the danger zone in terms of current demand at idle. Assuming whoever engineers the DC/DC charging systems takes any of this into consideration.
 
So this was for a 2018 with the 917 plug. Any folks who have intel on the 2016 model year split for alternators? I see some vendors have the aftermarket start at 2017 and some include 2016?
 
Great Thread, Thank you!
 
bjowett said:
Cool ducted air and heat shielding are requirements for any well loaded alternator, even stock units can benefit…. Otherwise, to some degree, we are just pissing into the wind.
Click to expand...
I have wondered if the location at the bottom was chosen for cooling reasons. Given all the downsides of having them submerged in water and getting choked by mud, I can't think of any other reason.
 
I didn't see it mentioned on their site, but I'm assuming these aftermarket alternators are not brushless? Meaning they would still be susceptible to dirt eating the brushes? Also, I'm not clear how your shop fixed the plug problem. This is an interesting upgrade. I'm very curious on longevity. Thanks!
 
joltman said:
I didn't see it mentioned on their site, but I'm assuming these aftermarket alternators are not brushless? Meaning they would still be susceptible to dirt eating the brushes? Also, I'm not clear how your shop fixed the plug problem. This is an interesting upgrade. I'm very curious on longevity. Thanks!
Click to expand...
The alternators by M2K/SBC are not brush-less.

Our interests are towing and off-grid camping. I don't really care to do the heavy off-roading, fording of rivers etc... Well I'd do it to save my life I guess...or maybe in someone else's Land Cruiser LOL. :p

However, I did look for a brush-less figuring that I might as well get one for the reason you mentioned. I mean why not? Brush-less might have been nice but was not a real requirement for me. What I wanted was simply the most power I could get with the most reliable hardware.

The only brushless one I found was made by Endura per the video & link referenced below. They are sold/made by a Company called Rapid Power who I reached out to. They replied in an email dated 10/4/2023 "Unfortunately we don't have anything suitable for your vehicle, really sorry we can't help".

I ultimately settled on the M2K/SBC due to it's robust build, super high power output and the simply awesome guys in the sales & tech department. I literally put those guys through the ringer with numerous rounds of niggling technical questions. Their patience is amazing. And I learned a lot about alternators.

I wasn't there for the mechanic modifying the plastic. As for how the mechanic modified the plastic he says he removed the plastic shroud which simply unbolts at the back. He then carefully used a precision sander (a Dremel type tool I assume) to carefully mill away what was needed. It took him only a few minutes he says. I imagine you could use a pair of nippers just as well.

BTW, the alternator has performed flawlessly. We pick up our new trailer this coming week with custom mods made by the dealer to charge the lithium batteries from the tow vehicle. The truck then goes in to the shop to have the alternator's wiring upgraded* and the Anderson connector put on the bumper.

*EDIT: by that I mean heavier + wire from alternator to battery, - wire from battery to frame and motor to frame.

Endura video REF:


Rapid Power REF:
Endura Power Brushless Alternators - Rapid Power - https://rapidpower.com.au/endura-power-brushless-alternators/
 
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FrazzledHunter said:
So thinking about heat and low RPM high power scenarios I looked into water-cooled alternators. I reached out to
Rapid Power. They replied they didn't have anything for the 200 series.
Rapid Power Alternators - Rapid Power - https://rapidpower.com.au/rapid-power/

I looked at other brands but gave up.
One thing I noticed was that the water cooled units had lower power output. I am assuming it's because cooling internals take up room.
So:
  • Get a water-cooled alternator with lower amperage but it might not overheat at low RPM plus is sealed against the elements.
  • Get a big honkin' alternator geared to spin faster and supply power at lower RPM's so it doesn't overheat in the first place
  • And so on...
Thinking about alternators can make your head explode.:bang:
Click to expand...
I really would like to get a sealed (water cooled) alternator as the alt location is susceptible to mud and water contamination.
Unfortunately so far there hasn’t been any marketed products, just one offs.

I did look into adapting alternative vehicle alternators that are water cooled by default (VW has a few) but making the mount work was non trivial. Now with carbon impregnated plastic 3d print adapters a possibility this might be a pathway again.
 
@FrazzledHunter you and I did the same homework, but you turned yours in! I was going to email those guys at Rapid Power and ask them if their alt would fit the 3URFE, however, after doing a little searching, it looks like there are 2 different part numbers for the alt in the VDJ200 and the 3URFE. Bummer that the SBC alt isn't brushless. I do find myself rarely going through a water crossing, and it can vary on depth. And I've seen that Jafffa Adventures guy. He's a little hammy in some of his videos, but his maintenance vids are spot on.

As to your shop upping the wire gauge from your alt to battery, you should check out this diagram from Blue Sea (weblink to article):

1709414204525.png


For your alternator to battery, you should probably put in at least 3/0 AWG(3 aught) cable. I know you're not going far, but you definitely want to size up. I would probably ask for 4/0 wire. And, the cable and wire that's used is super important. You want lots of fine stranded copper (not copper clad aluminum) wires in your cable. The jacket of the cable should also be resistant to oil and gas. You do not want simply "welding cable". I would recommend this at a minimum. You could also upgrade to their marine cable which fully meets ABYC code. <dad joke> We definitely want that because we're driving land boats. </dad joke>

For your camper (caravan for our Aussie friends) requiring 60A, I'd recommend the same type of cable above, but in the minimum of 2 AWG. Again, sizing up is important, so maybe consider 1AWG. It looks like Battery Cable USA also has an Anderson connector with 2 AWG cable they will sell you as well as a 1AWG. Just get a nice long length.

Probably wouldn't hurt to get some sort of plastic corrugated split tubing for all cables. Then pickup some heat shrink with glue in it and the proper sized tinned copper lugs for your ends. I'm a stickler for doing electrical correctly. I would want to do some homework and then know exactly what a shop would be putting in my truck.

I am not affiliated with BCUS at all. I've purchased cables from them for my 200 wiring to Blue Sea Safety Hub 150 and to my Victron 12/12-30 DC DC Charger in the cabin. They are high quality cables, but more importantly, they're rated to be in the engine bay.

Good luck! Hope to see some pix of the wiring job! I've never upped the alt wiring, and I'm curious where it snakes through the engine bay.

Jim
 
joltman said:
@FrazzledHunter you and I did the same homework, but you turned yours in! I was going to email those guys at Rapid Power and ask them if their alt would fit the 3URFE, however, after doing a little searching, it looks like there are 2 different part numbers for the alt in the VDJ200 and the 3URFE. Bummer that the SBC alt isn't brushless. I do find myself rarely going through a water crossing, and it can vary on depth. And I've seen that Jafffa Adventures guy. He's a little hammy in some of his videos, but his maintenance vids are spot on.

As to your shop upping the wire gauge from your alt to battery, you should check out this diagram from Blue Sea (weblink to article):

View attachment 3571680

For your alternator to battery, you should probably put in at least 3/0 AWG(3 aught) cable. I know you're not going far, but you definitely want to size up. I would probably ask for 4/0 wire. And, the cable and wire that's used is super important. You want lots of fine stranded copper (not copper clad aluminum) wires in your cable. The jacket of the cable should also be resistant to oil and gas. You do not want simply "welding cable". I would recommend this at a minimum. You could also upgrade to their marine cable which fully meets ABYC code. <dad joke> We definitely want that because we're driving land boats. </dad joke>

For your camper (caravan for our Aussie friends) requiring 60A, I'd recommend the same type of cable above, but in the minimum of 2 AWG. Again, sizing up is important, so maybe consider 1AWG. It looks like Battery Cable USA also has an Anderson connector with 2 AWG cable they will sell you as well as a 1AWG. Just get a nice long length.

Probably wouldn't hurt to get some sort of plastic corrugated split tubing for all cables. Then pickup some heat shrink with glue in it and the proper sized tinned copper lugs for your ends. I'm a stickler for doing electrical correctly. I would want to do some homework and then know exactly what a shop would be putting in my truck.

I am not affiliated with BCUS at all. I've purchased cables from them for my 200 wiring to Blue Sea Safety Hub 150 and to my Victron 12/12-30 DC DC Charger in the cabin. They are high quality cables, but more importantly, they're rated to be in the engine bay.

Good luck! Hope to see some pix of the wiring job! I've never upped the alt wiring, and I'm curious where it snakes through the engine bay.

Jim
Click to expand...
I'm familiar with Blue Sea - the breakers we will be using will be Blue Sea.
There is a DC-DC charger in the trailer and it is a REDARC BCDC1250D, I expect it to draw 60A to deliver 50A.

This means the power budget is expected to be as follows:
  1. 100A truck
  2. 25A 2nd battery
    1. Expected not to be drawn down that often. We use this battery mainly as a backup for jump starting and running the fridge.
  3. 40A charging the 100Ah Yeti Goal Zero 1500X portable battery.
  4. 60A trailer - only when towing obviously.
    1. I expect the REDARC to draw 60A to deliver 50A. If we have 400Ah (4800Wh) batteries that are discharged 10 10% that’s 4320Wh/600W or 7.2 hrs minimum to recharge the batteries. It is expected that this will be used only when towing.
So that’s 225A max. expected use. The way the alternator is installed with a 2” pulley we can get 200A at idle.

With that said I’d like to make sure the wiring for the alternator can accommodate at least 300A output from the alternator.
I do not expect to EVER reach the alternator maximum of 390A.
Getting 390A would require high engine RPM anyway and therefore isn’t practical.
 
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