LMTV Alternator replacement 24 volt

[GeneralDisorder]

As a contrary to Ronmar - no disrespect intended or implied because there's plenty of ways to skin this cat and it's down to what you are personally comfortable with - I would point out that the 260A is the standard alternator used on all A1P2 trucks and I have no reason to believe it's any different on the new A2 trucks (still running the C7 - heck maybe they all got the 300!) so surplus is not going to be an issue in my lifetime anyway. And if the world ends in nuclear holocaust and despite all odds and beyond reason you happen to still be driving your FMTV and need one...... There will be plenty of them laying around for the taking.

 

[Ronmar]

yep, lots of ways to do this! But by my observations, surplus supply has always been hit and miss, and not nearly as good a deal as it used to be especially as more people(hike the HumVee) have gotten into the LMTV arena. This is especially true when it comes to alternators it seems. In line with my personal experience, Alternators are consumables... with few exceptions(diesel tractor and a Mitsubishi EclipsE GSX I ran for 11 years) I have put an alternator on every vehicle i have ever owned at some point...

Can running these trucks be expensive? yes! Does it have to be? not necessarily... Cost not being an object is all well and good, but isn't it nicer when it doesn't cost?

Any plan involving power should always involve a power study. There is often a huge gap between what people actually need and what they think they need.

IMO 100A@24V/2800W is a LOT of power, but then again my home emergency generator is 3KW but I harvest waste heat from it also In my case, my service batts need 25A worst case. The truck may use another 25A max with everything turned on. That leaves me 50A to play with or <50% loaded. 50A@24V is the equivalent of 1200W of solar on the roof. If my service batts are charged, they won't need the 25A I have allotted to them, that's now 75A to play with or comparable to 1800W of solar on the roof... 100A@24V alts are pretty common, and not horribly expensive.

Just my take on something that should be simple and robust...

 

[GeneralDisorder]

Agreed. Power study suggests you could get away with a 100A alternator that is at times pretty close to running at capacity.....

On the other hand, the 260A in the same circumstances, will only be running at 1/3 to 1/2 it's rated capacity. Meaning it will run cooler and easily tolerate sending 68A to my house batteries even at idle. Remember that the 100A literally *isn't* 100A at idle. That rating is only if you rev it up. It's lucky to provide 60A at idle IIRC. Now I have to go drive the truck if I want anything decent from the alternator for house charging since I clearly can't turn on 68A of Victron Orion's at idle......

Sure I could run fewer of them. Charging will just take longer. But I don't wanna!

And I want 4 batteries for redundancy. 4 can be reconfigured to two. Two cannot be reconfigured to one. Not with 12v batteries and a 24v starter.

 

[Ronmar]

Well that additional alt load is only a backup for the 1600W solar on the roof anyway. I don’t expect it will be used much… Backup? we don’t need no stinking backup Thats what the house batteries are for, same as in many RV and marine configurations…

My main point is that 2800W is actually a LOT of power, and obtainable at not a horrific cost…