R100GS: EnDuraLast 450W Generator

... from Euro Moto Electrics.


Look, the design of the stock electrical system is astoundingly bad. Yes, it's better than the Zener shunt regulation which was current on Britbikes in 1970. No, it sucks compared to Japanese systems from the mid-Eighties onwards.

The worst aspect is the location of the diode board, inside the engine casing. Not only is there relatively little airflow, but the case gets more than a little warm when the engine is running. Semiconductor failure rates are exponential with temperature, and diode junctions are 100x as likely to fail at 100°C as they are at 40°C. And the diode board has 11 of these, baking away! Plus there's brushes to wear out, a field coil which doesn't operate if its warning lamp burns out, etc, etc.

The EnDuraLast system replaces all of these parts ... and all of its semiconductors are outside the engine cases!

This document outlines the operation of the regulator: Regulator Info .PDF.
I hope to take some measurements of my own and provide a little more information soon. In summary, though, this is a switch-mode regulator, and so "excess energy" is not "wasted" any more than a light bulb wastes energy while it is switched off.

The "450W" bit is a bit misleading, and misses the point anyway. Sure, it can supply 32A at ~8000rpm, but when is an airhead ever revving that high for long? The important point is that it can generate a lot of current even at low RPM ... it really should be called the "20A at ~2000rpm" generator, but I guess most people would miss the point!

Pack & Post

Very nicely packed for it's international trip, which took all of 4 days from the USA to Australia with USPS/AusPost. The stator/rotor were in not two, not three but FOUR boxes ... plus layers of foam and such.



I've ended up locating the rec/reg in exactly the same way as Bcostell did. I was considering mounting it on top of the coil, but I was a bit worried that it'd block airflow to the ignition module. It should get a fair bit of air back there. The space where the old regulator sits can be used for headlight relays.

There's suddenly a huge amount of space under that front cover!

(The bracket which the rec/reg is attached to was already broken. You can't see it, but there's an extra ground wire running forward to the bolts which attach the ignition controller, just to be sure to be sure. I tapped the power line into one of the blue/green wires in the loom. Yes, this bike really could do with a wash. No, the frame spine isn't bent, it's just the lens.)


My one criticism of the kit is that the electrical hardware supplied may cause problems for the overenthusiatic amateur. There's lots of folks who are quite decent home mechanics, but terrible butchers with their electrics. Those $5 crimp tools aren't worth a cent for a high-current application like this. EME supply a good assortment of parts so that you can construct a suitable setup for any airhead, but if I was them EME I'd pick the two or three most popular models (the GS almost certainly being one of them) and produce wiring kits for them. Other models would still require modifications, but at least there'd be an example to show how it is meant to be done. The risk is that dodgy installations will lead to electrical fires, and damage EME's reputation ...

I strongly recommed crimping and soldering and heat-shrinking all the connections. The crimp provides physical strength, the solder electrical conductivity, the heatshrink electrical (and moisture) insulation. For example, for the connection between the two red battery wires from the regulator and the fuse holder, I removed the supplied crimp barrel from its yellow insulating sleeve, cut bits of heatshrink to sit over the wires, crimped the wires into the barrel, flooded the barrel with solder (the solder gets drawn into the wires by capilliary action, magic) then shrunk the bits of heatshrink around the joint to provide a double layer of insulation. I'll try to remember to take some photos next time.

More information

There's an EnDuraLast thread on ADVrider too. Actually, there's several. Try searching for 'EnDuraLast' or '450W'. I need to copy some of the information I posted in those threads back into this page when I get the chance.

Of particular note is this comment from Kevin Beretta, who's on his way 'round the world:

15,000 miles of abuse so far (www.nohorizons.net). Still charging as if new. The battery is getting abused (overnight charging of computer etc.) but seems to be holding up. Glad I got this setup, as the other day it took 2 days to cover 40 miles over a pass, at walking pace. Strange to not get out of first gear for 2 days ... The RPM's were low, thankfully there was cool air to cool the bike. Not sure how you would do it with a stock setup ... I don't think I got over 3k rpm...


I'm not an employee or representative of EuroMotoElectrics, just a satisfied customer. There are less radical alternatives out there, like the Omega 400W system from Motorrad Elektrik, which has been around a lot longer, and have a very good reputation too.
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