Voltage regulator

[Dave]

Hi, whats the maximum volts that should be measured at the battery terminals with the engine running, on putting a meter on the battery on my commander i get a reading of around 15 volts at tickover(lights off), and 15 volts at higher revs with all lights on, is this a bit high? my manual shows 13-14 volts as a maximum, does this mean my voltage regulator could be faulty, or is it within acceptable limits, thanks dave ( can a voltage regulator get an intermittent fault?,)

[graham]

Hello Dave,Anything higher than 14.2 volts is too high.You've probably caught it just in time, the regulator side has failed but the rectifier is still working. Unlikely to be intermittent, just not so noticeable until you boil a battery, pop a headlight bulb or destroy an ignition box :-).Graham

[Richard Negus]

Dave,There was an apparently trivial assembly fault on some Commanders which may be the cause of your high reading - and worth checking.The regulator is fixed to a plate mounted on the r/h side of the fuel tank, with the regulator earth wires (black/white x 2) going to one of the M5 fixing bolts. The loom earth ring terminal should go the the same bolt - but some bikes had it fitted under one of the plate fixing nuts. Over time, this can corrode and introduce a high resistance, making the regulator think that battery voltage is low and put out more amps.Clean all the ring terminals and put them together on one bolt.My boat engine has an external 'intelligent' regulator to control the 70A alternator output. This initially displays 14.8 - 14.9 volts and gradually reduces to 12.7 as the battery becomes full. A voltage over 15.0 would cause me concern on any charging system.While you're looking, check the 3-way connector block by the generator. That often suffers corrosion in the terminals, causing heat to melt the plastic housings.R.

[Ian]

"My boat engine has an external 'intelligent' regulator to control the 70A alternator output. This initially displays 14.8 - 14.9 volts and gradually reduces to 12.7 as the battery becomes full. A voltage over 15.0 would cause me concern on any charging system."Can I get one of these for my Commander?

[Richard Negus]

Sorry - no, different rectification/regulation systems.The bike alternator chucks out its full a/c output all the time and the regulator converst it to d/c and limits the charge into the system. Any excess is converted to heat (which is why the box has fins).A car-type generator has an internal rectifier and separate internal regulator that controls the output in accordance with the load. Low battery = full output, full battery = minimal output.My boat system does away with the simple internal regulator, replacing it with a programmable one that gradually ramps the output up after starting, maintains a fixed output for a while and then ramps down to a steady trickle charge when the battery volts have stabilised.R.

[Dave]

Thanks for your replies, i have only just found time to have a look at the bike, the wires on the regulator were on the one bolt, and although they looked clean i did remove and clean them up, however on checking the 3 wire connector Richard mentioned, it has got the covers burnt through on the two wires that run across the plastic connection block. (this is the covers over the blade connectors, not the block itself which is perfect, so whether it was engine heat that caused it or just shorting between the two i don't know ) The covers are burnt right through, and it appears the wires have been touching at times, i will have to remove the block and make good the connections, could this cause the symptons i mentioned??, but either way they will have to be repaired, thanks again for all your replies, dave

[Ian]

Hello there, a bit of advice please.I have an ammeter on my Commander and it says that after startup my battery is charging at more than 16 volts. I've checked this with a voltmeter and it is actually 17.1 volts. OK, not good and probably why I boil batteries!After about 10 miles, when I suppose the batteries are now fully recharged, it drops back to the officially agreed figure of 14.1 volts.I have checked and cleaned the earth connctions on the regulator and also the 2 x black and white wires. All seemed good, but I did them again. Also I checked the block connector from the alternator. As new.So, should I look somewhere else, and if so, where? Or should I bite the bullet and buy a new regulator?The bit that puzzles me is that the blasted thing seems to work fine after 10 miles or so...All suggestions welcome!Ian

[Interpol2471]

Ian I have a Commander Regulator. It is not brand new but believed to be a good spare, one thing it is original and not a copy replacement. If it is any good to you I can sent it and if it works perfectly I guess it is worth £25.00 plus postage if it doesnt work for you just post it back.

[Ian]

That's very generous and I'll take you up on the offer, if it is still OK.Where do you want the money sent?Thanks again.Ian

[Interpol2471]

Ian PM sent to you

[Ian]

I've replied but it seems stuck in the outbox.How can I make the reply send?Ian

[Interpol2471]

got both lol

[johnbirchjar]

Are there any early warning signals to look out for if the rectifyer/regulator are going on the blink,?or do they just stop working,J.B.

[Dell Boy]

Your battery runs dry due to "boiling up" & the battery performance falls off. Last saturday John I thought when you started your bike the battery sounded sluggish. Didn`t notice it on wednesday though. Derek.

[Ian]

Hello all.Well, see my posts above for symptome, but I can say that a new regulator fixed the problem. It was a b****rd job though. I never knew those lads at Shenstone had such small fingers and three baby-sized hands... Cue for jokes, but it would be unworthy.The bike ran fine, just boiled battery fluid away until I bothered to check it.Ian

[Dell Boy]

All that space in the headlamp fairing with easy access, cooling airflow & dry & they stuck it all in the hottest, most inaccessable place with water splashing over the electrics when it rained. Whenever I work on a piece of machinery I always think the guy who designed this should have been required to service/repair it for a year & see if it would be the same after a year or much modified. To change the petrol pump on a Suzuki Supercarry van you have to unplug an electrical connection located above the petrol tank in a one inch gap. If the lead was just two inches longer it would be a doddle to get hold off but it isn`t & it is a real struggle to unplug & plug in the new unit. End of moan. Happy fiddleing!!! Derek.

[kanonkopdrinker]

Quite .... try changing an oil filter on a Nissan Micra!!

[Interpol2471]

Glad I could help Ian, at least thats one more spare the wife isnt moaning about that I have left somewhere in the kitchen