Alternator/reg/rec question ...

[daktulos]

I took a 45 minute trip recently to see my mother recently with the headlight on. Unfortunately, I turned the key too far and left the side-light on when I parked it. After a couple of hours, I needed a jump start to get going again.

A 5W bulb for 2 hours is about .8Ah and the battery is 10Ah I think, so it clearly wasn't anywhere near fully charged or at full capacity.

I have a cheap battery, and I'm definitely not sure it was fully charged, so I'm not too worried about it.

However ... in the garage, I started the engine with the headlight on to check it is charging. The headlight brightens noticeably once the bike has started and idles which I expected, but revving the engine caused it to dim somewhat, which I wasn't expecting.

So, here are my questions: Is this normal? Is the alternator/reg/rec on the sv650 (curvy) so finely balanced that riding with the headlight on could result in the battery discharging? Or, does it look like I may have a problem?

Thanks.

[Bibio]

first thing you should be asking yourself is how old the battery is.

most charging problems are due to a fubar battery and not the charging system.

a fully charged battery should be able to keep a good 12-13v charge for days/weeks not connected to anything.

[daktulos]

It's two years old - I do make short journeys and start the bike occasionally without going anywhere, so it's not going to be fully charged when I left (it's a council garage away from the house, so no power either).

[Bibio]

unless there is an alarm fitted to the bike the battery should hold a 12-13v charge for a good month or two.

take the battery out and charge it in the house. once charged take the charger off then check the voltage after a week or so, it should still be the same charge voltage or very near.

[R1ffR4ff]

Further to the good advice you have been given get to the main Connector block between the Stator and the R/R and check for corrosion on the pins and sockets.

Unfortunately mine is located under the rear seat fairing so it was seats off and fairing off and it took a while for me to spot the two small JIS(Phillips look alike) screws near the rear underneath that have to be removed as they were hard to see.Before I put them pack I painted them with some white paint just so I would know where to find them next time.

If corrosion found remove with a small jeweller's/electrical screwdriver with a bit of 500 grade grit/wet-and-dry paper wrapped around the end and gently rub the male and female contacts to remove corrosion.Then blow them out with some Carb/Brake cleaner and let dry and then and spray out with Electrical cleaner/Contact spray(I also treat mine with ACF50).

https://www.toolstation.com/shop/Automotive/d60/Lubricants+%26+Sprays/sd2795/Contact+Spray/p81507

Any build up of corrosion on these High Current contacts causes electrical resistance that robs the charging circuit of current and can eventually lead to component failures and the connector to melt and possibly short and destroy parts in the system.

[SV650rules]

It's two years old - I do make short journeys and start the bike occasionally without going anywhere, so it's not going to be fully charged when I left (it's a council garage away from the house, so no power either).

Can you get a solar trickle charger to mount on garage roof out of sight to keep the battery happy, they are fairly cheap these days and well worth thinking about if your garage has no electricity supply.

[glang]

I took a 45 minute trip recently to see my mother recently with the headlight on. Unfortunately, I turned the key too far and left the side-light on when I parked it. After a couple of hours, I needed a jump start to get going again.

A 5W bulb for 2 hours is about .8Ah and the battery is 10Ah I think, so it clearly wasn't anywhere near fully charged or at full capacity.

I have a cheap battery, and I'm definitely not sure it was fully charged, so I'm not too worried about it.

However ... in the garage, I started the engine with the headlight on to check it is charging. The headlight brightens noticeably once the bike has started and idles which I expected, but revving the engine caused it to dim somewhat, which I wasn't expecting.

So, here are my questions: Is this normal? Is the alternator/reg/rec on the sv650 (curvy) so finely balanced that riding with the headlight on could result in the battery discharging? Or, does it look like I may have a problem?

Thanks.

45mins riding should be plenty to charge the battery - remember the R/R isnt a trickle charger so puts plenty into the battery until the the volts come up.
The standard R/R is very crude in operation and actually dumps the excess power of the generator as heat (hence adequate cooling is very important) once the correct system voltage is reached so, at higher revs, using more power like lighting actually helps the R/R.
Your lights dimming when revved is unusual and I cant think of any explanation so best to follow the steps that have been recommended....

[R1ffR4ff]

Another alternative for a bike in a council garage with no power is what I did for a pal in a similar situation.I kept and old but good car battery from a scrapped car.Got him to fit an SAE connector


https://www.ebay.co.uk/itm/Battery-Tender-SAE-DC-Power-Automotive-DIY-Connector-Cable-with-Fuse-Fad-RT/253581404551?hash=item3b0aa12987:g:tzMAAOSwB09YQA5 v

to his battery like I have for my Maintenance charger.And the another one with some big crocodile clips to go on the Battery.Fully charged the Car battery lasts for months as a float-charge for his SV650. Electrically the bike thinks it's got a 60amp+ reservoir.

You do really need a car though as he takes the Car battery away and charges it from time-to-time.


My SAE connector is discretely run under the rear seat/frame and you can't see it unless you were looking for it.

HTH :)

[daktulos]

Thanks all - the solar charger would be a problem as there's another garage above me and it would be a bit awkward to get a wire out of the front. I might give the car battery idea a go, as I do have a car to lug it about. I was actually thinking about putting an SAE connector (or similar) in anyway so I could carry something like this around with me:

https://www.amazon.co.uk/DBPOWER-12000mAh-Portable-Emergency-Flashlight/dp/B01DLRGY8A/

But then I decided that it was crazy and I should just try and find/fix the problem.

As well as checking the connectors, etc., if I have time I'll check the voltages at the battery and lights this weekend, and I may even see if I can get an ammeter in line (although not when starting).

[R1ffR4ff]

Thanks all - the solar charger would be a problem as there's another garage above me and it would be a bit awkward to get a wire out of the front. I might give the car battery idea a go, as I do have a car to lug it about. I was actually thinking about putting an SAE connector (or similar) in anyway so I could carry something like this around with me:

https://www.amazon.co.uk/DBPOWER-12000mAh-Portable-Emergency-Flashlight/dp/B01DLRGY8A/

But then I decided that it was crazy and I should just try and find/fix the problem.

As well as checking the connectors, etc., if I have time I'll check the voltages at the battery and lights this weekend, and I may even see if I can get an ammeter in line (although not when starting).


I have one of those but it might not be any use through the SAE connector as the current they supply is very large.However it's bailed my Car out of the poo several times as I've not been using it much in the Winter and the Alarm drains the battery :O


It's still good to fit an SAE connector though as then it's easy to plug a charger in when needed.Also it supplies my Keis Heated inner gloves in the cold.

[daktulos]

I have one of those but it might not be any use through the SAE connector as the current they supply is very large.However it's bailed my Car out of the poo several times as I've not been using it much in the Winter and the Alarm drains the battery :O


I did have a look at it, and there are SAE connectors with AWG 12 wires which may do it, and there are US sites with AWG 10 wired connectors which should definitely work, but I never managed to find an answer about what the connector is rated at ... but this is really just idle curiosity as I'm not going down that road.

[R1ffR4ff]

I did have a look at it, and there are SAE connectors with AWG 12 wires which may do it, and there are US sites with AWG 10 wired connectors which should definitely work, but I never managed to find an answer about what the connector is rated at ... but this is really just idle curiosity as I'm not going down that road.

These power boosters are well worth having as the USB battery block can be used with mobile phones anyway and they come with all the connections for Android/Iphone etc :)

[daktulos]

So, I've had a look at as much as I can - the generator looks fine (resistance within normal range, output on all three pairs rising from ~25V to ~90V going from idle to 5k RPM). All contacts clean and corrosion-free.

With the engine started and idling, the R/R was generating 14.1V. At 5k RPM it was 13.7V, with the headlight on at 5k it drops to 13.3V.

For some reason I didn't write down the voltage idling with the lights on. But, the voltage drop without the lights on would explain why the lights are dimming. At the end of the day, 13.3V means it would still be charging the battery to some degree.

So, my conclusion is that my battery isn't holding its charge as well as it did when new, and I probably need a new one at some point.

That said, I'm still a little concerned about the R/R voltage drop as the engine revs. Either the R/R is having trouble, or there's something drawing a lot of power when I rev.

Anyway, thanks for all your help!

[Biker Biggles]

I would start by checking all the connections from alternator to battery and battery to earths.Then borrow a known good fully charged battery and check those charging numbers again. You might find it all checks out with just that.

[glang]

If your RR is worrying you have a search on here or in the manual and it shows how to check its diodes. This wont completely discount it as a problem (unfortunately theres no easy way to check the internal voltage regulator part) but at least reduces the possibilities....

[R1ffR4ff]

So, I've had a look at as much as I can - the generator looks fine (resistance within normal range, output on all three pairs rising from ~25V to ~90V going from idle to 5k RPM). All contacts clean and corrosion-free.

With the engine started and idling, the R/R was generating 14.1V. At 5k RPM it was 13.7V, with the headlight on at 5k it drops to 13.3V.

For some reason I didn't write down the voltage idling with the lights on. But, the voltage drop without the lights on would explain why the lights are dimming. At the end of the day, 13.3V means it would still be charging the battery to some degree.

So, my conclusion is that my battery isn't holding its charge as well as it did when new, and I probably need a new one at some point.

That said, I'm still a little concerned about the R/R voltage drop as the engine revs. Either the R/R is having trouble, or there's something drawing a lot of power when I rev.

Anyway, thanks for all your help!

Faulty batteries can cause spurious readings and no end of problems.If you are looking for a new battery my SV came with a Dynavolt Sealed gel and is 3+ years old and no signs of failing.If it did I would buy a Motobatt AGM replacement as I have one that is 6 years old from an older Bike but won't fit the SV :(

Proper Sealed Gel or AGM batteries come"Sealed"maintenance free and fully charged and are,"Fire-And-Forget".

[Bibio]

So, I've had a look at as much as I can - the generator looks fine (resistance within normal range, output on all three pairs rising from ~25V to ~90V going from idle to 5k RPM). All contacts clean and corrosion-free.

With the engine started and idling, the R/R was generating 14.1V. At 5k RPM it was 13.7V, with the headlight on at 5k it drops to 13.3V.

For some reason I didn't write down the voltage idling with the lights on. But, the voltage drop without the lights on would explain why the lights are dimming. At the end of the day, 13.3V means it would still be charging the battery to some degree.

So, my conclusion is that my battery isn't holding its charge as well as it did when new, and I probably need a new one at some point.

That said, I'm still a little concerned about the R/R voltage drop as the engine revs. Either the R/R is having trouble, or there's something drawing a lot of power when I rev.

Anyway, thanks for all your help!

those figures are fine. 13.3v @5k with lights on is a tad low but not enough to worry. i would say that there is a furred connector somewhere rather then the charging system being fubar.

dont but cheep battery's, its false economy.

[daktulos]

those figures are fine. 13.3v @5k with lights on is a tad low but not enough to worry. i would say that there is a furred connector somewhere rather then the charging system being fubar.

dont but cheep battery's, its false economy.

Thanks - the resistance from r/r to the battery was 0.2 and 0.4 ohms, which doesn't look too high to me. I'll hold off and buy a decent battery when I can afford one!