No no dont try this connection two batteris and end up destroy your starter, yes you can paralell two battery and get twice the amp. But you dont get 24V, thats if you connect them in series, dont see any point doing this. I have never had problems starting engine even if its winter and cold, buy a good battery and problems gone.

I agree, 24 volts will increase the current thru the starter a great amount. Brushes will arc more and the starter will take a hit on longevity. Paralleling 2 makes more sense. The actual starter voltage will rise under load and a volt or so more makes a huge difference in starting power. Will not hurt the starter and will actually make it last longer as it will be working better in its design range.

Way back ( I know I am dating myself) hey I'm 65. It was pretty common practice in the early 50's to change out a 6volt battery in a car with a hard starting engine with an 8 volt battery. You had to re-adjust the regulator so it would charge, put a "voltadrop" going to the tube type radio or change the vibrator I think, hey I was a kid but I paid attention. Everything else was fine. A couple more volts made the starter much more efficient. 1955 or so, 12volt batteries showed up. Kind of makes you wonder how the 6 volt point and coil could make a spark at all under tough starting conditions... I expect Jumper cables were the norm....

Here's the info, not mine but is what has been done and do successfully run 24v through the starter. Unless a person physically tries something ,any guess as to what will or won't work is just that, A GUESS. I personally wouldn't do it unless absolutely necessary and only after trying a parallel setup, then have at least one extra starter waiting to be replaced.

It looks to me like this is 12V battery, the charging is 12V. And they are hooked up for paralell giving 12V, sure he didnt mean to get twice amount off AMP to startermotor and the normal for the rest? Honestly i cant find any good reason for making all this, just connect two battey in paralell and thats it you have all the amp you need.

Ya it does look to be a parallel setup , never really looked at it close, just put it in my "possible fixes" folder for how they had it hooked up. Although I think with the extra relays when the starter button is hit it switches that system over to series. It does that so nothing is 24v otherwise and both batteries get charged.

I had remembered about it with my new bike and its need for more juice. One high amp/hr battery solved it but had to go with the new tech. One thing I can say is through the years I've done a lot of stuff that people insisted just won't work only to find it works great and solves a big issue, not whats needed here though.

My battery is 9Ah, it fits and gives enough power. I have 55W headlight, heated grips, LED rest of the bulbs. Most importen thing with battery is maintence and charging, check you charging and give the battery external charging now and then. Use a good charger that will max it.

If i dont recall someone wrote about lithium beeing low on amp, thats not correct. You can buy them with 18Ah same size XT use, give us feedback how it works out with charging system on the bike after a year thanks. And dont forget you need special charger for lithium battery if you want charge it at home.

The setup on the drawing is a parallel-setup when relay#1 is deactivated and series when relay#1 is activated..

It's "common" in system where you have increased volume and compression. The reason to do it is that torque increases with voltage. It will also spin faster when cold.

The starter doesn't get supplied with 24V but far less, typically 16-20V, current will also increase which might burn your wires...


The starters tend to last for a while, but on a standard engine I would rather have fixed the problem.

Edit:
Two batteries in parallel is not a good solution. The worst battery will always discharge the better one, and guess what happens if a battery gets an internal short....

Great way to destroy the startermotor, it was never built for this. Many ways getting thing to work, how long it last is another question..

Well, the starter-motor will probably make it for a while. Increasing voltage is a common way to increase torque - usually for a limited time.

In many cases it will be better for a motor to run on higher voltage for a few seconds then to struggle on max torque and low/no speed for 30 seconds.


If you are really interested in "what things are built for" you should not install a battery with a lot more CCA then your ordinary battery. Your wiring and starter are not designed for it and you might have enough current available to fry it.
Remember that unlike most other electrical motors the starter have no protection (overcurrent, overload, temperature, etc).

But again; I would not have done this on a standard bike. This comment was to tell that some people use 2 batteries in series without issues.

http://unitedhoisting.com/wp-content...tinguisher.jpg

Mezo. :blushing:

It's not the voltage that kills you!
 

My old night-classes-in-electronics lecturer used to demonstrate this very well; he took an old 12V battery and simply put a wire across the terminals holding the ends of the wire in contact with two insulated pliers.
The red glow turned to white hot and, pretty soon after that, the wire melted.
This was his demonstration of how a fuse fails, thereby performing as per its' purpose and design.

'Elf and safety freaks avert your eyes, but I very much doubt that such great demos of fuses are done in colleges nowadays.