I have a battery problem.

[sonofwind]

Hi eveyone.I built a diesel bobber which has 10 hp Katana diesel engine and 4 speed gearbox.I don't like pull start and I want to use a battery for my bike.12v 36Ah and 12v 45 ah battery are both big size and heavy but 12v 20Ah battery is very well dimensions for my bike which has small and light.Is it suitable for my 10 hp diesel engine or what should i use (ex:12v 12Ah,12v 18Ah etc)and my last question:Can i use ups batteries?Thank you for your help...
My bike is here.
https://fbcdn-sphotos-e-a.akamaihd.net/ ... 0160_n.jpg

[coachgeo]

Nice Nice looking bike. do a search for industrial equipment (Generators, Farm Pumps, Mowers etc.) that utilize something close to the specifications of your engine and then see what their OEM battery specifications are. Then consider something just a little better lol.

Im sure some folk will pipe in on your Battery Questions soon.

[gilburton]

I used a yb14-A2

[sonofwind]

Nice Nice looking bike. do a search for industrial equipment (Generators, Farm Pumps, Mowers etc.) that utilize something close to the specifications of your engine and then see what their OEM battery specifications are. Then consider something just a little better lol.

Im sure some folk will pipe in on your Battery Questions soon.

Thank you very much.My engine needs 12v 36ah or 12v 45ah baterry but they are both big size and heavy.I have to find more small battery than others.

[tappy]

If you do a search on here you'll find various threads concerning the best types of batteries for diesel motorbikes. Getting good quality AGM batteries and the like can help as they can deliver very high cranking power. Beware that the "CCA" ratings (cold cranking amps) and reserve quoted are at fairly idealised conditions - you can use them to compare batteries of similar types and quality, but not really to give you absolute numbers.

If your engine has pull start, it probably has quite a heavy flywheel and possibly a decompressor? If so, then you can use these to seriously reduce the peak torque - and therefore starter amps - during starting.

If your engine doesn't have a decompressor, perhaps there are other decompressor systems from other engines that will fit? Many of these engines - particularly the singles - are pretty similar in layout and function.

[sonofwind]

If you do a search on here you'll find various threads concerning the best types of batteries for diesel motorbikes. Getting good quality AGM batteries and the like can help as they can deliver very high cranking power. Beware that the "CCA" ratings (cold cranking amps) and reserve quoted are at fairly idealised conditions - you can use them to compare batteries of similar types and quality, but not really to give you absolute numbers.

If your engine has pull start, it probably has quite a heavy flywheel and possibly a decompressor? If so, then you can use these to seriously reduce the peak torque - and therefore starter amps - during starting.

If your engine doesn't have a decompressor, perhaps there are other decompressor systems from other engines that will fit? Many of these engines - particularly the singles - are pretty similar in layout and function.

Thanks Tappy.Yes,I searched but these are not answers of my question.My engine has decompressor.

[Eddy Wane]

You mentioned using UPS batteries. I would not recommend using them they are designed for running continuous power (although they do not last long doing that on a mains power UPS) as opposed to high instant current for engine starting. It is the obvious choice to find an automotive battery to start your engine. Have a look at the specs for Honda Goldwing or Harley if you want a motorcycle friendly size of battery. Do not forget that it is not only the size but how quickly you can recharge the battery so that you can guarantee starting every time.
Eddy.

[tappy]

Great - so your engine has a decompressor!
How is the de-compressor activated? Is it in any way automatic? Does it have to be used when you use the electric starter?
Depending on your answers it may be possible to use it to seriously drop the current drawn when using the starter motor, and therefore allow use of a much smaller battery.

[sonofwind]

Great - so your engine has a decompressor!
How is the de-compressor activated? Is it in any way automatic? Does it have to be used when you use the electric starter?
Depending on your answers it may be possible to use it to seriously drop the current drawn when using the starter motor, and therefore allow use of a much smaller battery.

It's not automatic.I use decopressor before I start the engine.Thanks for your help;Tappy

[gilburton]

I can't understand why you need such a large battery as 20+amps?
Most people with 10hp single cylinder engines usually find that any large bike battery around 14 amps is enough.
Is your engine similar to the Yanmar type Chinese clones? I don't think these are available in the UK but may just be different name brand for your market?
Another option might be to have 2 smaller batteries linked in parallel ??

[sonofwind]

I can't understand why you need such a large battery as 20+amps?
Most people with 10hp single cylinder engines usually find that any large bike battery around 14 amps is enough.
Is your engine similar to the Yanmar type Chinese clones? I don't think these are available in the UK but may just be different name brand for your market?
Another option might be to have 2 smaller batteries linked in parallel ??

Hi gilburton.I think that all chinese 10 hp diesel engines are similar.I used 12v 7 amp battery and engine didn't start .So I used 12v 45amp baterry(the factory of my engine adviced to me this battery )and it started easily but it is both big and heavy.12v 20amp has almost semi-power of 12v 45 amp and I think that 12 v 20amp jel baterry starts my engine.14 amp is wonderful size for me.I was glad to hear it. Thanks:D

[tappy]

If the decompression is manual, then hold it open and turn the engine over gently by hand a few times. If it turns over freely then the slightly open valve isn't touching the piston so all should be well. If you run the starter motor like that it will spin the engine up with very little current. Once the flywheel's got that momentum you can release the decompressor and the motor will still be able to keep spinning it over without huge peak currents so it'll start.
If you can get hold of a clamp meter you can measure the starter motor current and then choose a battery to suit.