Topic: Will Ander's Charging system fix my low battery problem?

[Xxthegonzxx]

Hi all,

I have a 1978 CB750F. I've upgraded the following:

-Dyna S ignition
-Dyna 3ohm coils
-55/60 Watt HID headlight
LED tail light and regular non-LED blinkers.

With all these upgrades I constantly have a low battery problem. I have my bike on a trickle charger every night and once it's fully charged I turn it on and the headlight lamp is very weak. I can only drive it for about 45 min to an hour max then it dies.

I've posted before and HondaMan commented  that because of my upgrades my stator/alternator cannot produce enough to charge my battery. I know that forum member Anders produced a stator upgrade for the CB750's. It supposedly produces up to 32 amps (32 amps x 12V = 384 watts?). Anyway, my question is this. If I upgrade to Ander's stator will my system produce enough to power everything? I would love to ride my bike more than an hour!  Would love some input guys/gals. Please help me out here as this is killing my motivation.

[flybox1]

You say it cannot produce enough to keep your batt charged......well, what is the state of your charging system? 
Do you have a known good battery? 
In what rpm range do you do most of your riding?
What is the voltage at the battery at: rest, key on, idle, 2000rpm, 3000, 4000, 5000?
Have you adjusted your regulator to compensate for the draw?

[Xxthegonzxx]

You say it cannot produce enough to keep your batt charged......well, what is the state of your charging system? 
Do you have a known good battery? 
In what rpm range do you do most of your riding?
What is the voltage at the battery at: rest, key on, idle, 2000rpm, 3000, 4000, 5000?
Have you adjusted your regulator to compensate for the draw?

I checked the three yellow wires in the stator and had a mechanic check the stator before my rebuild and all was well. Charging was working. At the moment I'm only taking the bike to work and back which is about a 5 min drive away.  No freeway speeds and the RPM range to work and back averages about 3k-5k with some stops. The battery is brand new and tested well. The voltage of the battery at rest is about 13.4 and when I rev the engine higher than 3k RPM the battery reads 12-13V range but not much higher. The regulator rectifier is an upgraded all-in-one unit from electrosport.

Here is HondaMan's quote as well:

With 3-ohm coils and a Dyna S, you have now maxed out the alternator capacity on your 750. If you also have a halogen headlight more than 50 watts, you will have a perpetually low battery problem. This is because: the Dyna S uses 1.2 amps extra current, and the coils use another 1.4 amps on top of that. This totals to:

(1.2 + 1.4) amps * 12 volts = 31.2 extra watts being consumed.

This will also slowly begin to melt your RUN-OFF switch, and the Red and Black contacts in your keyswitch.

[flybox1]

You say it cannot produce enough to keep your batt charged......well, what is the state of your charging system? 
Do you have a known good battery? 
In what rpm range do you do most of your riding?
What is the voltage at the battery at: rest, key on, idle, 2000rpm, 3000, 4000, 5000?
Have you adjusted your regulator to compensate for the draw?

I checked the three yellow wires in the stator and had a mechanic check the stator before my rebuild and all was well. Charging was working. At the moment I'm only taking the bike to work and back which is about a 5 min drive away.  No freeway speeds and the RPM range to work and back averages about 3k-5k with some stops. The battery is brand new and tested well. The voltage of the battery at rest is about 13.4 and when I rev the engine higher than 3k RPM the battery reads 12-13V range but not much higher. The regulator rectifier is an upgraded all-in-one unit from electrosport.

Here is HondaMan's quote as well:

With 3-ohm coils and a Dyna S, you have now maxed out the alternator capacity on your 750. If you also have a halogen headlight more than 50 watts, you will have a perpetually low battery problem. This is because: the Dyna S uses 1.2 amps extra current, and the coils use another 1.4 amps on top of that. This totals to:

(1.2 + 1.4) amps * 12 volts = 31.2 extra watts being consumed.

This will also slowly begin to melt your RUN-OFF switch, and the Red and Black contacts in your keyswitch.

see the bold statements above.
you should get over 14v at the battery at 4000+rpm
you dont spend enough time above 4000 rpm to allow your charging system to actually charge the battery.
your battery will run out because of this.
if riding at a higher rpm doesnt help, and your vreg is maxed, you'll have to get rid of something to decrease the need.

[calj737]

It does sound as though your charging at a lower than optimum rate. Another consideration is to change your headlight from Halogen to LED. They are not inexpensive, but they do draw far less current.

[Duanob]

Try this diagnostics:

http://www.oregonmotorcycleparts.com/FAQ.html

Worked for me. I had three bad wires/connectors that were preventing full charging of the battery.

[TwoTired]

Your alternator makes 210 Watts at 5000 RPM and about 1/3 of that at idle (70 watts).   

Unless you rev the engine, there is no way your stock alternator can run the bike with all your "upgrades".  So, the battery is supplying the offset power draw until it depletes.

[Scott]

G'day Gonz
Mate I put Anders alt upgrade on my bike about 3 weeks ago.
Before the upgrade my volt meter reading at the battery was 3000RPM = 13.5v and 4000RPM = 14.5v
After the upgrade my volt meter reading at the battery is        900RPM = 14.5v  and 1100RPM = 14.6v
I put heated grips, spot lights (LED), head light upgrade to 60/100 halogen (with relays)and a 12v outlet to charge phone.  I plugged at volt meter into the 12v outlet to read while I am ridding, turned heated grips up to full, spot lights on and head light on high beam.  The volt meter changed from 14.6v down to 14.5v.

I'm not sure if this helps but if you want me to do any other tests or info let me know.  I love mucking around with my bike and any excuse to do so is welcome.

Scott

[Xxthegonzxx]

Your alternator makes 210 Watts at 5000 RPM and about 1/3 of that at idle (70 watts).   

Unless you rev the engine, there is no way your stock alternator can run the bike with all your "upgrades".  So, the battery is supplying the offset power draw until it depletes.

Makes sense to me. Unfortunately this is going to kill my short rides. Anders' upgrade is looking more and more appealing.

[Xxthegonzxx]

G'day Gonz
Mate I put Anders alt upgrade on my bike about 3 weeks ago.
Before the upgrade my volt meter reading at the battery was 3000RPM = 13.5v and 4000RPM = 14.5v
After the upgrade my volt meter reading at the battery is        900RPM = 14.5v  and 1100RPM = 14.6v
I put heated grips, spot lights (LED), head light upgrade to 60/100 halogen (with relays)and a 12v outlet to charge phone.  I plugged at volt meter into the 12v outlet to read while I am ridding, turned heated grips up to full, spot lights on and head light on high beam.  The volt meter changed from 14.6v down to 14.5v.

I'm not sure if this helps but if you want me to do any other tests or info let me know.  I love mucking around with my bike and any excuse to do so is welcome.

Scott

Thanks Scott!

That awesome that it's working great for you. It sounds like this upgrade is well worth the investment and time. How difficult was the install? Did you have to piece your own stator cover together or can you use the Honda Stock cover?

[Scott]

Install is a easy.  The couple of times I had questions I emailed Anders and he got back to me very quickly.
You take off the front sprocket cover, gear shift cover and alt cover.
Hard bit for me was taking off the rotor (you need a puller)
Then put the new rotor on, take the existing 2 stators out of the alt cover and put in the new one.
Run the wires up to the new regulator which I mounted on the side of the battery box and put the covers back on.  At this point I got slowed up a bit because I forgot to order new gaskets and had to wait for them to come in.

The wiring is easy.  3 wires from the stator to the regulator and 2 wires form the regulator to the battery.
I left the existing wiring in place and just tied it up out of the way rather that cut it out.

The things that took a little bit of time and I do mean a little bit only was making sure the wires from the stator were positioned inside the cover correctly so that the rotor did not touch them and then mounting the regulator on the side of the battery box, to do this I removed the existing regulator and rectifier and made a simple "L" bracket to move the starter solenoid over a bit.

I can email you a photo if you want from my phone but I'm not sure how to put one on the computer.

Any questions, please ask.
I going to work now but will be home latter today
Scott

[anders288]

 On the F bikes I mount the regulator upside down under the battery box. I remove and discard vapor chamber cut off it's mounting tab use the pem nut studs I supply.
 Same way on 77-78 K bikes and early K bikes.

[MRieck]

On the F bikes I mount the regulator upside down under the battery box. I remove and discard vapor chamber cut off it's mounting tab use the pem nut studs I supply.
 Same way on 77-78 K bikes and early K bikes.

...and it works perfectly I can say from experience. Whole system works fantastic.

[Parkwood60]

You could always try turning off your headlight during the day. My charging system was not putting out enough power and I fixed it by just putting new connectors on the end coming from the stator. I'm sure someone on here can tell you what the resistance should be between the 3 yellow wires, but mine was high measured at the rectangular plastic plug, and still higher than the suggested ohm reading where the bullet connectors plugged in under the shifter cover. I may be wrong, but your Dyna shouldn't use much more power, and your alternator ought to put out more for a net higher reading as you rev the motor. But you are saying it reads lower with the bike revving to 3000rpm. My guess is you're alternator isn't putting out anything at all. Test the voltage at the yellow wires with the motor running and see what you got.

Anyone have the link to a troubleshooting flow chart specifically for these bikes handy?

[andy750]

+1 on Anders upgrade. I have it on my CB750K4 and run heated gear (gloves and jacket liner) in the Winter. Now in the summer it just makes my 55w Halogen nice and bright. I also have a Dyna S with CB900 coils and never have a problem with low battery. As Scott said its a constant 14+ v. Works for me.

Install was easy and Anders did mine

cheers
Andy

[Xxthegonzxx]

Alright I hate to revive an old post but I just thought I'd update. I ended up buying Anders alternator upgrade. Here are some pictures if the install. It was pretty straight forward although I did come across some minor issues.









Does anyone know what the hell these are? I didn't drain my oil prior to the install so just I left my side cover off with the oil pan underneath to catch the drips. These were in the oil pan.



Another angle:




Sent from my iPhone using Tapatalk

[Xxthegonzxx]

After doing a google search, it looks like they are rollers from the old alternator. Can I put everything back without these?


Sent from my iPhone using Tapatalk

[Jerry Rxman Griffin aka MuthaF'er]

Those are not alternator parts. Those are the starter clutch rollers. There should also be 3 springs and 3 caps. That clutch is attached to the back of your old rotor.

[PeWe]

I had charging problems with Dyna S and 3 ohms coils. (CB750K6-76)
I replaced the coils after first test ride when the headlight could not be on without discharging the battery really quick. Changed to 5 ohms coils, much better but still not enough. I need to trust the bike without need of connecting my battery charger after each ride. Charge battery one day/month when not used is Ok

Went back to points with Dyna 5 ohms coils (new TEC plate) and NO problem with battery voltage despite headligtht on daytime (H4 55W)

[MRieck]

After doing a google search, it looks like they are rollers from the old alternator. Can I put everything back without these?


Sent from my iPhone using Tapatalk

Yes. The new rotor has a much better roller set up than the the original 3 rollers. Make sure the 3 springs and spring caps are with the old rotor too.

[Bankerdanny]

You could always try turning off your headlight during the day.

Is that legal? I thought headlight on all the time was a federal law, that's why bikes built from the mid 70's or so onward don't usually have an off switch for the headlight.

[MRieck]

You could always try turning off your headlight during the day.

Is that legal? I thought headlight on all the time was a federal law, that's why bikes built from the mid 70's or so onward don't usually have an off switch for the headlight.

Not in the case of FJ1200's....they can do whatever they like.

[calj737]

Not Federal, Danny. State-by-state. Like helmets and lane splitting.

[2wheels]

What about something like this?

7 inch headlight with LED's that could be the day time running light.

http://www.ebay.ca/itm/7-INCH-ROUND-H6014-H6017-H6024-CHROME-GLASS-AMBER-LED-RING-PROJECTOR-HEADLIGHTS-/141267930462?pt=Motors_Car_Truck_Parts_Accessories&hash=item20e4398d5e&vxp=mtr

[PeWe]

You could always try turning off your headlight during the day.

Is that legal? I thought headlight on all the time was a federal law, that's why bikes built from the mid 70's or so onward don't usually have an off switch for the headlight.

My bike (CB750K6-76) has an headlight off switch.
Off, Parking, Headlight On. I have a headlight reflector with 5W parking light and H4 for Hi/Lo.
Left side switch for HI or LO.
I think this is typical for European deliveries.

I have one new right handle bar switch extra for just on/off. Think that is for US bikes. I missed the Parking so I ordered a new from Germany with same functionality is the OEM switch for my bike that was too old and ugly.
http://www.ebay.de/itm/Honda-CB-400-F-750-Four-K3-K6-Lenkerschalter-Armatur-rechts-Neu-switch-handlebar-/360743748559?pt=DE_Motorradteile&hash=item53fe00c3cf

Left side:
http://www.ebay.de/itm/Honda-CB-500-K2-750-Four-K3-K6-Lenkerschalter-L-switch-handle-bar-left-side-/360901625022?pt=DE_Motorradteile&hash=item540769c4be

These might not fit CB750 F?