Battery questions

[Excess Impulse]

I have searched through the forums and read the thread about batteries, but I'm still not exactly sure I know what I need. I want a compact battery. My bike is a 1980 SOHC, and I'd like to make a small compartment under the seat to put all the electronics as others have done. However, after reading about amp hours, etc, I'm still in the dark. I have the starter on, but the bike kicks over so easy I don't think I'd need to use it. I prefer to kick it, but I will leave the starter in place...for now. So, what options do I have if I
1) just want to run non led lights (brake, tail, turn, indicators, headlight) and kick start only.
Or 2) all the above but with the possibility of electric start if I feel lazy that day?
I have seen the small batteries(anti gravity, etc) with over 200 crank amps, but it's really the amp hours I don't understand. People have said the bike will burn up the wiring, scary stuff like that if it's not right. Can someone clear this up for me?

 

[thegrouch]

For sure you can't ride the bike without the battery. The "amp hour" is typically stating a total charge in the battery and is used mostly to "size" the battery. I mean "11Ah" is smaller than "25Ah". This value doesn't really mean anything special unless you use your bike only for really short rides; Then it may happen, that after 10th start and <10miles ride your battery will start losing power (etc.) if you choose too small capacity.

To crank the engine it is the "crank amperage" - as you mentioned. The 11Ah Yuasa may give you around 160Amp and this depends strongly on condition of the battery and its temperature.

Nowadays Li-Po batteries are being more popular to "simulate" a normal 12V battery, but I don't think it is a good idea to use them in a vehicle. They are very prone to low temperatures and different other issues like overcharging/overdischarging etc. With the bike that uses pure mechanics to ride - don't go this way; in case your charging system fails you will (I think) do more miles on a standard battery.

You can try installing a smaller battery and see what happens. If you notice problems with the electric starter - you will know it's too small (thanks God there is a kickstarter)


regards
oscar the grouch

 

[Excess Impulse]

Oscar the grouch,
Thank you for your reply. I was beginning to wonder if I just asked a dumb question, or if nobody knew the answer. I did see in the online manual it says the standard battery is 12 amp hours.
I also have seen pictures here in posts of guys running these smaller batteries, but can never find them when looking, and was hoping that anyone that had used them would chime in on the subject.
I can believe the cold weather will affect the charge(my lithium ion batteries for my drill/driver go dead in the cold garage soon after charging) but if I only ride in warmer weather, and go for longer rides, and use kick-start only, will a lower amp hour battery work out ok?
Particularly looking at the Anti Gravity 8 cell, which is 9 amp hours, and would be small enough to stash under the seat.

 

[Excess Impulse]

I certainly don't want to be the helpless poster that asks questions without a thorough search, but have been really stumped after looking through and not finding the information I needed. After some more research, it looks as though the Lithium Ion type batteries can be troublesome for our charging systems. Some people run them without much trouble, some have less than desirable results. Seems like a led acid based AGM battery would be a better solution.
I'm still back to concerns(questions) about the lower amp hours, which are only a concern if you
1) go for short rides and use electric starter?, or 2) use a lithium ion battery?
If just using the kick-start and running longer rides, the lower amp hours on an AGM battery is not an issue?
Sorry if it sounds like I keep asking the same question, just want to get the correct battery in the smallest possible size.

 

[thegrouch]

I haven't been using this kind of battery "replacement", I'm just talking about differences between li-ion and lead acid batteries.

Li-ion have advantages - smaller size, higher currents, longer "on the shelf" life, less of self discharge currents. They may serve well if made well. For 180$ I suppose this antigravity stuff should be OK.

Lead-acid battery is a crude technology, it will survive almost anything. Li-ion must have additional electronics for protection, which will cut off the ie. battery if voltage rises too high. I could expect, that if your bike and its electric system is in a good shape - the Li-ion will work well and you won;t have any issues even with 9Ah or even less.

If your regulator is bad or some wiring problems arise - you may experience higher currents in your wires, some power cuts or very short life of the battery...

On the other hand - if people are using it - means it works (at least for some of them)

regards

 

[XSLeo]

Amp hours is a rating on battery size. As mentioned a 25 AH battery is larger than an 11 AH battery.
Now what does amp hour mean. With an 11 AH battery it means that the battery can supply a current of 11 amps for one hour. or 1.1 amps for ten hours.
This knowledge can help when your charging system goes south. You can determine how much the bike draws from the battery. As in 5 amps. Divide the Amps in the amp hour rating by the draw, as in 11 divided by 5 = 2.2 this means your bike with a 5 amp draw can run about 2.2 hours on just the battery.
Leo

 

[Excess Impulse]

That is good information to know, and explained in a way i can understand! I dug a little deeper and did find that if going kick start only, I can use a low amp hour battery,and not have to spend around $200 on an anti gravity battery. http://www.batterysharks.com/Yuasa-NP2-3-12-p/np2.3-12_b12-2.3.htm It looks like this may be the one I get.