Bonneville Alternator Output - Triumph Forum: Triumph Rat Motorcycle Forums
Twins Technical Talk Technical Talk for Hinckley Triumph Twins: Bonneville, T100, Speedmaster, America, Thruxton, and Scrambler.
Sponsored by: Long Beach Motorsports

LinkBack Thread Tools Display Modes
post #1 of 3 (permalink) Old 12-03-2012, 03:14 PM Thread Starter
Grand Prix 250
Main Motorcycle: 2010 Bonneville (mags)
psychodeathbot's Avatar
Join Date: May 2012
Location: Saint Paul, MN, USA
Posts: 76
Other Motorcycle: BMW R1150R
Extra Motorcycle: Masi CX (man-powered)
Bonneville Alternator Output

I'm trying to figure out just how much juice can be gotten out of the charging system to run accessories on a mag wheel bonneville.

Here's what's on the draw side...

Running Gear
ECU/Ignition 100
Headlight 55
Tail/Brake light 21
Turn signals 10

Vest 45
Grip warmers 25

Total draw = 256W

According to the manual, the output is 23A @ 2000 RPM, which means about 275W (@ 12V), so it looks like I could run the accessories I want. However, I've read that the rectifier is weak, so the actual output at idle is probably just barely enough to keep the stock running gear from killing the small (10 AH) battery.

I'm not well-versed in electrics, so I'm wondering what options are available to boost the charging system so that the battery can remain charged at idle. Bigger battery? Better rectifier?

psychodeathbot is online now  
Sponsored Links
post #2 of 3 (permalink) Old 12-04-2012, 03:39 AM
Super Moderator
Site Supporter
Main Motorcycle: Custom 955 Speed-Tona
DEcosse's Avatar
Join Date: Feb 2005
Location: Pleasanton CA
Posts: 17,979
Originally Posted by psychodeathbot View Post
ECU/Ignition 100
Nowhere near = 1/2 that at most
(predominantly Fuel Pump - after that, is minimal - if Carb a LOT less)

... Tail/Brake light 21
Turn signals 10...
You can get rid of most of this by converting to LEDs
Also - remove front parking light bulb - ever use that feature?

Adding 70W is not a problem - even if you are discharging slightly momentarily at lights etc, for most part when riding normally you will not and will recharge any lost at this time
DEcosse is online now  
post #3 of 3 (permalink) Old 12-04-2012, 05:06 AM
Senior Member
Supersport 600
Main Motorcycle: Bonneville T100 Black2012
Captain Bert's Avatar
Join Date: May 2012
Location: South Australia
Posts: 169
Other Motorcycle: prev: BSA,Suzuki,Yamaha
with any generating system the output is dependant on a few things
1: the number of turns in the armature
2: the strength of the magnetic flux in the field windings or pole magnets
3: motion, rpm , turning etc.
at idle the output is minimal until revs are increased to a point where
max output is achieved. There is nothing to increase output at idle apart from a bigger generator or rpm. The circuit diagram I have the generator looks like a 3 phase ac output, put through a 6 diode network to give 12dc. Life expectancy of the rectifier is only compromised if it output rating is exceeded for extended periods and heat! + over voltage spikes if any!
Captain Bert is offline  
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Triumph Forum: Triumph Rat Motorcycle Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter your valid email address, that can receive an automated confirmation message. Otherwise, you won't be able to gain full access.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Similar Threads
Thread Thread Starter Forum Replies Last Post
Alternator output? Tiger Workshop (archive) 2 07-19-2008 06:37 PM
alternator output okiecityflash Classic, Vintage & Veteran 3 04-15-2007 08:45 PM
alternator output of S3... TiggerTwo Speed Triple Forum 2 01-08-2006 12:44 AM
Alternator Output Trophy 1 10-27-2004 08:55 AM
Alternator output Hinckley Classic Triples 2 04-20-2004 01:47 PM

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are On

For the best viewing experience please update your browser to Google Chrome