mik*2 replied:

It should be charging around 14 volts. It could be either your voltage regulator or the alternator. I don't know whether your regulator is part of the alt or not. My guess is that it is. Either way you should get someone to check it out and tell you for sure. In most cases if you take it somewhere, they'll check it out on the spot and tell you if it needs repairs or not.

cheers
mike

Mark replied:

An alternator should charge a lead acid battery at 13.5-13.8 volts for maximum recharging when low. It should then trickle charge at ~12.5-12.9V when nearly recharged. However, 12.59V will slowly recharge a flat battery, hence you have probably not noticed the problem, especially if you do long runs and otherwise have a good battery.

I am not sure what alternator the lux runs, but it looks like only the regulator may be at fault. A 5 year old alternator will probably have used a significant percentage of its brush life and who knows how well the bearings are fairing. If you can remove/repair the alternastor yourself, simply replace the regulator (usually buit in to the alternator) and check everything else while its out. But if unsure, get an auto sparky to do it, last thing you want is a flat battery at the boat ramp!!!

But do get the alternator checked properly, it would not be the first time a RACQ volt meter is out and you have a good battery that simply when flat because the lights were left on!!!

Cheers

Mark

Nav 80 replied:

Shaun,,, A blown diode can produce the same simptom with a low charge rate, get it checked by a auto sparky.