Li-ion Battery

Oops. Got one of these Shindengen kits and Motoelectrix advises it won't work with my charging system as the KZ750 has a field coil instead of a permanent magnet system. However... It seems to me the problem I'm trying to solve is the old r/r would fry my new Li-ion battery. So if I installed the new MOSFET r/r I get a nice rectified and regulated current to charge the battery and kept the old regulator circuited through the field coil to power all the lights etc I should be OK? Can't have too many regulators no?

Bowman wrote: Oops. Got one of these Shindengen kits and Motoelectrix advises it won't work with my charging system as the KZ750 has a field coil instead of a permanent magnet system. However... It seems to me the problem I'm trying to solve is the old r/r would fry my new Li-ion battery. So if I installed the new MOSFET r/r I get a nice rectified and regulated current to charge the battery and kept the old regulator circuited through the field coil to power all the lights etc I should be OK? Can't have too many regulators no?

Why run two? Cant' you just run everything off the new r/r?

I'm well over my head here but my trusty manual tells me that the stock regulator sends a switched current to the field coil turning it off and on as necessary to keep the dynamo output at 14-15V.

The new MOSFET unit is wired to the output of the dynamo and after it does its r/r duties it sends a + to the battery to charge it and a - to ground.

So if I get rid of the old regulator I no longer will be switching the field coil on and off (if that matters) but it also sends current to everything else (lights etc.). If I can live without switching the field coil I suppose I could jumper the output of the new MOSFET unit to the now unused + and - that were connected to the old regulator?

Alternativelydoes anyone know of a modern r/r unit that plays nice with a charging system that has a field coil?

I would start by taking a look at the 1976 KZ750-B1 wiring diagram to see the number of wires running from the generator to the rectifier (you will see there are 3 yellow wires because the bike has a 3-phase charging system). Then I would determine if my new combo rectifier/regulator has the capability to attach those 3 yellow wires. If it does not, it will not play nice with the generator.

Take a look at the link below. It contains the wiring diagram for the 1976 KZ750-B1. Ed

kz750twins.com/wp-content/uploads/2009/07/kz750b1.jpg

baldy110 wrote: Been using one for about 7 years now on my ELR, bought the battery in 2008. It has never been on a charger and I do not do anything to it during the winter just ignore it. Every spring it fires the bike up like new. Expensive but with going on 7 years of use I am very happy with it.
It was not a drop in replacement but wasn't to hard to get it to work. When I need a new one I will buy another.

With this track record how can you go wrong....... will seriously think about this when my fairly new standard one dies. Outstanding bike of the month too.

Yes indeed the wiring diagram (and the bike) has 3 yellow wires coming from the generator. The new r/r has a three pin connector meant to accept those 3 yellow wires and a 2 pin connector they say should be routed (+) to the battery (+) terminal and (-) to ground.

I guess at this point I'm wondering if I have a properly regulated and rectified current going to the battery and I ditch the old regulator then all that means is I'm no longer cycling the field coil off and on, it will always be off. [strike]Does this matter?[/strike]

OK, that was a stupid question now that I've read a bit and beginning to understand how my generator works. Sent an email to oregonmotorcycleparts.com to see if they have any ideas.

Bowman wrote: I'm well over my head here but my trusty manual tells me that the stock regulator sends a switched current to the field coil turning it off and on as necessary to keep the dynamo output at 14-15V.

That is the "modern" style of regulation used in most cars alternators. There are two coils: the spinning armature coil and the static field coil. By varying the small current through the field coil you control and adjust the large current in the other coil which feeds the electrical system load. This design only supplies what you need.

The old motorcycles were different: the coil windings crank out full current and there is a shunt that passes the excess to ground. It's kind of wasteful because it essentially runs wide open and shunts what isn't going to the system load to ground but it was cheap and it worked.