[...the maximum voltage stated in the service manual (15.5V for the NC700)...]
If it ever got to 15.5V, something is amiss with the Reg/Rec because voltage that high will probably "cook" the battery! I have a digital voltmeter mounted on my bike and when riding, it reads 14.3-14.4V, with no other electrical drains except my GPS which only takes a microscopic amount of current. If I'm using my electric vest, it will drop 0.2 to 0.5 volts depending on the heat setting.
Last edited by DirtFlier; 14th January 2018 at 04:33.
I know, it’s extreme but this the reference value that Honda give us in the service manual and it’s not a typo... I doubt that we will ever see that. Probably under extreme conditions like high heat...
Anything more than 14.6 V is not suggested for an AGM battery. 14.4 V is the sweet spot to keep sulfation low, and have more accurate OCV readings, but it has the disadvantages of more grid corrosion and can cause gassing.
I forgot one important thing about the charging system test: engine’s RPM. Must be around 5,000 where is the maximum output of the generator. Though 2,500 - 3,00 and up will be ok.