ST1300-MOSFET Rectifier upgrade

[HelloEveryone]

Newer generation motorcycles are using MOSFET instead of the old style rectifier like the one found on the ST1300 which runs super hot and tends to break down overtime.

The modern bikes the MOSFET are placed in cooler location away from the alternator.

Anyone tried upgrading to MOSFET successfully?

The old traditional rectifier runs super hot, overtime will burn connectors and wears out faster and less stable voltage.

The never MOSFET type rectifier design runs cooler, better battery life, stable voltage with less stress on connectors.

Given than the alternator is sitting in between the V block where airflow and ventilation is not great, the alternator takes on a lot of heat stress.

Wondering if anybody has successfully upgraded to MOSFET transistors rectifier for ST1300.

 

[wjbertrand]

150,000+ miles on my 05 ST1300 when I sold it. The regulator and rectifier assemblies were still working fine. My cheap aftermarket battery was 8 years old as well, indicative that the charging system was not abusing it. Given the effort to access the alternator and the lack of reported problems for this part, it’s not worth the bother. If for some reason the rectifier fails, one could consider the options at that point.

PS, the part you have circled on the diagram and pictured is the regulator, not the rectifier, that is part #11.

 

[tnbill]

The st1300 alternator has an internal regulator and diode set. The mosfet units from all i have seen are for external permanent magnet alternators where yours is a field controled unit

 

[SMSW]

Replacing the internal VRR with an external one should not be difficult for someone with a decent electronics background - but you would probably have to either build it yourself from scratch or cob together pieces from other charging systems. Either way, as I said, knowledge is all. Since these parts are not considered to be one of the known issues with ST1300's and are long lived, why bother? Digging down in the bike to work on the alternator is not a trivial task, giving more reason to not do this 'upgrade'.

 

[Sadlsor]

I'm unaware of a real issue (as more than a handful) on the ST1300.
The early Honda Blackbirds, however, and some VFRs, were notorious for flaming hot voltage regulator/ rectifier.
My '97 XX smoked the VRR, and I heard someone singing to me. The battery, under the seat, was whistling and screaming like a tea kettle on the boil.
That battery WAS boiling.
STs, not so much.

 

[Alberto]

Thanks, now I know that there is such a thing as an "active bridge rectifier". I think it’s not complicated to build, but the main problem will be fitting everything into the same space as the old diode rectifier.

 

[Al st1100]

Thanks, now I know that there is such a thing as an "active bridge rectifier". I think it’s not complicated to build, but the main problem will be fitting everything into the same space as the old diode rectifier.

Your not a Honda engineer

• Application: While common in industrial and some advanced automotive designs for better efficiency, most standard automotive alternators still use high-performance press-fit diodes for reliability.
• Modification: If upgrading or converting, active rectifiers can be used, but must be designed to handle the high current demands of the vehicle's electrical system.