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[m1ks]

One thing that's been throwing me, I've always worked on the principal of 14.7v max charge rate from the Reg, but in online literature, manuals etc and in this video it mentions output from the reg at 16v max?
It's weird as everything seems to be fine otherwise, starting and running OK, battery not bubbling or fizzing, (aside from the rear tail light not working but that's a feed problem, just need to work back from the feed in the loom)
I guess we'll see what happens with the new Reg/Rec when it arrives

[Les H]

Hi Mk1S...I would say that just over 15V that you are getting is acceptable and not worth changing the regulator, as I'm pretty sure they will all be very similar. It might be worth measuring the charging current (in series with the battery)...and I doubt that it will be much above 1 amp fully charged. Some slight gassing of the electrolyte will occur but not so much as to boil it dry very quickly. It seems that auto regulators have quite crude electronics and the regulation curve is quite shallow rather than a steep cut off characteristic that you would expect from a Laboratory Power Supply, so when they start to limit the voltage there is some overshoot but nothing to really worry about.

[Les H]

I’ve done some more studying as regards charge voltages of lead acid batteries. If you study the article: http://www.autonopedia.org/renewable_en ... Volts.html....... you will see the plots for “12v lead Acid Battery State of charge vs Voltage” on the x axis at 100% charge you will have the plots that correspond to the C/5 to the C/40 charge rates …where C equals the ampere hour Capacity of the battery. At around 15.5V battery voltage you will see the curves equate to something like a little over a C/10 charging rate. Now if your battery is a 5 ampere hour capacity, it will mean you battery is being charged at around 5/10 or ½ Amp. This would seem an acceptable amount of overcharge and enough to ward off sulphation at the expense of some water loss. The 14.7 volt maximum charge level we talked about equates to the 2.45V maximum per cell a shown in this article: http://batteryuniversity.com/learn/arti ... id_battery...... but probably does take into account the slight internal resistance of the battery as is shown in the first article. I hope this dispels some of your concern, as regards the regulator, and hopefully if you have sent back the original reg. the one you get back is OK too.

[Les H]

CORRECTION: "but probably does NOT take into account the slight internal resistance of the battery etc etc.

[m1ks]

Thankyou kindly and wow, that's a brain scrambler, especially for this time in a morning. As electrics were never a strong point of mine and you seem to know your stuff I'm quite happy to accept that you've clearly thought this through and it's thoroughly appreciated and has put my mind at rest a bit, the battery ultimately isn't an enormous worry, they're cheap enough and if one is damaged I can then dig further into the causes, given it's working and holding a charge is miraculous anyway as it was bone dry when I got the bike, fortunately fresh battery acid and a couple of days on the optimate revived it. Topping up occasionally is no problem.
My real concern was possible damage to other parts of the electrical circuitry. I've requested a replacement unit anyway do we'll see what that does and if it's about the same then fair enough.

[m1ks]

Just for interest, the video I referenced but completely neglected to link to is this: