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To blast, or not; CO worries; sticky loo valve; splitting the charge; what horsepower?
QMy alternator’s internal regulator allows the voltage to rise to 14.7v, but I have lead acid batteries which, I understand, should not be charged at more than 14.4v. The alternator is a pattern replacement; it has the main B+ output, the W terminal (for rev counter – not required) and just two other terminals: L (for the warning lamp circuit) and a small + (for connection to the batteries while the engine is running). Would it be possible to insert something into the path of the feed to the small + terminal to force the alternator to bring down its output voltage?
ATONY REPLIES… I assume that the small terminal is for a battery sense cable, in which case increasing the voltage on it is likely to reduce the alternator’s charging voltage. It is easy to fool the regulator into boosting the output voltage by inserting a diode in this cable to cause a voltdrop; however, raising it is a different thing all together. You may be able to purchase a voltage booster, but you are only looking at 0.3-volt and obtaining that with stability across the operating temperature range is unlikely to be easy. You might be worrying unnecessarily. Modern lead acid batteries have changed from a lead-antinomy plate alloy to lead-calcium or lead-calcium-silver. The calcium increases the battery’s gassing voltage significantly so it may well be 14.8 volts – but check with the battery manufacturer’s sheet.