Rectifier-Regulators, types & differences SH775 SH847 FH020, Shunt vs. Series

[whatnissan]

This is what I ended up doing to mine hooking it up to my open loop cooling system. Doing this it keeps the regulator from overheating (not sure why it does) and continues to charge my ski and run normally.. My harness looks fine and I’m running the 2021 new style stator that goes straight to the regulator so I’m not sure why but it will charge for like 20 30 min get hot then stope charging.

[K447]

… the regulator … it will charge for like 20-30 min get hot, then stop charging.

Which specific voltage regulator are you using?

Which battery type and capacity? AGM?

How old is the battery?

[whatnissan]

It’s a new battery less than a year old it’s the 2010 style battery so it’s bigger agm. I’m using the stock regulator. It all seemed to charge and work well this weekend.

[jetplane]

It’s a new battery less than a year old it’s the 2010 style battery so it’s bigger agm. I’m using the stock regulator. It all seemed to charge and work well this weekend.

I was thinking the same , I think that the key is to go with AGM battery .

[K447]

… mine hooking it up to my open loop cooling system. Doing this it keeps the regulator from overheating (not sure why it does) and continues to charge my ski and run normally..

My harness looks fine and I’m running the 2021 new style stator that goes straight to the regulator so I’m not sure why but it will charge for like 20 30 min get hot then stop charging.

It’s a new battery, less than a year old.
it’s the 2010 style battery so it’s bigger AGM.

I’m using the stock regulator.

It all seemed to charge and work well this weekend.

So your stock SH775 rectifier module has water cooling, and the AGM battery voltage stays close to 14 volts with engine running, even after riding for more than 30 minutes, correct?

AGM battery tends to absorb more amps continuously from the charging system until the battery reaches very close to fully charged.

It makes sense that the stock SH775 SCR type series rectifier would get quite warm while it is rapidly charging the AGM battery. The rectifier’s internal self-heating should abate once the AGM battery gets closer to fully charged, when the amps flowing into the AGM battery reduces.

[whatnissan]

If I’m idling I see 13.2 on the dash but if I’m riding it’s like 13.6-13.8 or so

[K447]

… riding it’s like 13.6-13.8 or so

If you compare the dash reading with a multimeter reading directly at the battery, you may find the dash reading is offset from actual battery voltage.

[1tommygunner1927]

This thread needs to be a sticky! Very useful info.

[CapsFanBen]

Shindengen SH847 appears to be a series type regulator.
I suspect (at the moment) that the SH847 is using SCR semiconductors (so not the cooler running mosfet transistors).

Let me make sure I understand. A FH020 will cause the stator to run hotter, but the regulator itself will run cooler than the SH847 (presumably because the SH847 is non-MOSFET).

I am hoping I can get to the bottom of this. This threat is one of the best I have seen on this topic. I actually don't have a jet ski. I have a 2016 Triumph Street Twin. The stock FH020 is located on the fork, but I would like to relocate it to behind the radiator where it is much hotter and there is much less airflow. Apparently Triumph relocated them to this location in later model years I think because movement of the fork was causing too much stress on the wiring in the stock location. However, I am a little hesitant because of the heat issue. I was considering getting an SH847, but it sounds like this may not be a good idea for my purposes?

[TimeBandit]

When comparing the two common types of shunt regulator designs (aka SCR -vs- MOSFET), both still do a good job at shunting Power by means of 100% current flowing (circulating) back into the next stator windings, when energized, complements/attracts the rotors approaching magnetism poles - hence the shunting "unloads" the rotor. This works because shunting is a timed/phased short in rotational successions, verses fully shorting the entire stator at once.
The difference, is that the MOSFET type is a more pure 100% flow than the SCR type because SCR's have a bit of internal resistance within them, resistance = heat. MOSFET having super-low resistance is why the regulator housing the MOSFETs runs cooler than SCRs.

As for the stator running hotter with MOSFETs, I cannot buy into that notion. With the regulator offering less resistance, the stator and rotor are seeing less "work" in heating up the regulator.