WTF - Watt the fock?

[Rob Frankham]

You can increase the Voltage output at low RPM by fitting a diffrent Voltage regulator, its available from BMW Motorworks in the UK and the part is located under the fuel tank, part number is ELA44410

Site link https://www.motorworks.co.uk/vlive/Shop ... 5&spPage=3

Sorry, the Motorworks statement is rubbish. The voltage regulator can't increase the output of the alternator at low revs. This is dictated by the alternator. The regulator is designed to reduce the output to maintain the required voltage no matter what the revs are.

What the 'high voltage' regulator does is set the output voltage of the system to a higher voltage independant of revs, provided the alternator is capable of producing that voltage... which doesn't happen until the output of the alternator is capable of supplying the required voltage into the ambient load.

In effect, what you are getting is a higher voltage on the battery once the engine is running at greater than - say - 2,500 rpm. at lower revs than that, there will be no difference. The good side is that it will bring the battery to full charge quicker once you are riding at road speed... useful if you are doing short periods of riding interspersed with periods of idling... but not in 'normal' use. The downside is that a higher voltage on the battery isn't necessarily good for it and could reduce battery life.

The bottom line is that the only way to get higher output on an airhead (if you really need it...) is to replace the alternator and the only way to get reliable charging at or just off idle is to fit a geared or belt driven alternator with the shaft speed stepped up to a useful speed.

Rob

[Zombie Master]

Installing my Led headlight H4 replacement, has my voltmeter always sitting at 13 volts. It's a 15 minute install and costs under $100.

I wonder if one of these new, very compact, lithium power packs could be installed as a buffer for the main battery.

Probably could be mounted near the main battery.

If you have to pack a rotor, and diode board along as a back up, perhaps adding pre-charged storage. could be a simpler solution.

I often plug a battery maintainer into my accessory socket when I park it.

[jackonz]

BMW Motorworks never claimed that fitting the higher voltage output regulator would give more current, only that it would begin charging at lower RPM, new style batteries such as AGM require a higher voltage to charge them.

In all cases the oly way to get more current in a Airhead is to replace the generator with a higher output unit.

[Rob Frankham]

BMW Motorworks never claimed that fitting the higher voltage output regulator would give more current, only that it would begin charging at lower RPM, new style batteries such as AGM require a higher voltage to charge them.

In all cases the oly way to get more current in a Airhead is to replace the generator with a higher output unit.

Okay, I can see that perhaps my point wasn't clear enough. The 'police' or 'high output' regulator does not allow charging to begin at lower revs, no matter what Motorworks say. The regulator (any regulator) does not affect the output of the alternator at all (either in terms of voltage or current) until the output voltage reaches the limiting voltage of the regulator. No stock type regulator ever increases the output of the alternator (either in terms of voltage or current) it only reduces (limits) it.

Rob

[jackonz]

Am sorry but in this case you are wrong.

[Rob Frankham]

Am sorry but in this case you are wrong.

Justify...

Rob

[daz]

Jackonz, AGM batteries (glass mat) are actually sensitive to overcharging. You want to be careful not to put too high of a charge so as not to do damage. Also, voltage (pressure) and amps (current) (rate) are two different things. Although of course related.

[PAS]

daz, My PC680 has this written on the battery: cyclic charge voltage-14.4-14.8V. Any battery would be sensitive to over charging, dont you think?

[barryh]

Any Valve Regulated Lead Acid battery is sensitive to long term overcharging as excessive gassing off can release electrolyte via the safety valve. That includes AGM and Gel batteries but of the two Gel is usually more sensitive due to the possibility of gassing creating bubbles in the Gel.

You can equally make a case that an AGM is sensitive to under charging in that it's life will be compromised if it never gets up to 100% full charge. To take a battery from 80% to 100% during the so called absorption phase takes several hours at the manufacturers recommended voltage. For PC680 that would be 14.7 volts. Odyssey specifically warn against using a trickle charger to achieve a full charge as it needs that 14.7 volts.

[daz]

Actually PAS that's where the confusion comes in. Those new light weight lithium batteries like to be charged at a greater voltage than we usually use on traditional batteries.