I've recently replaced the voltage regulator on my TW125 and it seems the voltage is a bit high for the AGM 12V battery that's inside.

At the moment, I have north of 15V unloaded with just the full battery connected and 14,6-7V with the headlights on.

I suspect this is just due to production tolerances (it's probably a chinese-built regulator copy) but I'd like to keep my (new!) battery working and not gas it prematurely.

So I thought of putting a big power diode in the regulator to battery line but I'm afraid of frying it... Please note I didn't say I was putting a diode between the battery and the starter. The common wisdom is to never run a motorcycle without the battery : is it to keep a load on the regulator? smooth the output? not completely clear depending on where you ask... But in any case, I'm afraid of a regulator malfunction because of that.

Am I in the clear or is there something I'm missing?

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    \$\begingroup\$ Inserting a diode between the battery and regulator isn't a good idea. The diode will prevent the regulator from sensing battery voltage. \$\endgroup\$ – AlmostDone Feb 26 '18 at 14:17
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    \$\begingroup\$ 14.6 V doesn’t sound very bad unless ambient temperature is very high. You’re not spending that many hours charging it but sure, over the course of one year, you will loose some water. If everything else fails and you can’t replace the regulator, a sturdy 14.something V zener diode with a resistor in series should clamp it. \$\endgroup\$ – winny Feb 26 '18 at 14:31

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