Topic: battery question for cafe bike (i searched...)

[timdhawk]

Im looking for the thinest battery that i can find meeting the 12v 14Ah minimum for a 78 cb750. I have scoured the web (okay 4-5 places) and and searched here and can only come up with batterises right at 3" in width.

Anybody have any links or know of any batteries that are smaller in width than 3" that can lay on its side?

any ideas or info would be appreciated! thanks

[KingCustomCycles.com]

Try Batteries America out of Wisconsin.  I use them for my Unmanned Aerial Vehicle power needs. 

[dusterdude]

you might look at batterymart.com too

[MJL]

How about a cycle x alternator and forget about the battery? Kick start only...

[timdhawk]

How about a cycle x alternator and forget about the battery? Kick start only...

$500 vs. maybe $75.00... att his stage i'll go for the battery. (i did consider it, though!)

[eldar]

You are going to find 3 main types; lead-acid, gel, agm and all are about the same size for the amp hours. You can ditch the starter (or not) and use a smaller battery. If you want it on its side, I suggest an agm though.

[gribbs]

What specs should I be looking for if I want to buy a small battery that will power only headlight/tailight/gauges?  As in what volt, AH, etc?  man I know nothing about power or wiring   

[eldar]

Well voltage is always 12. if you are doing just lights and such, a 7 should be enough. Maybe even less if you switch out the incandescent bulbs for LEDs and the headlight for an HID setup.

[mateo tomas]

Try Batteries America out of Wisconsin.  I use them for my Unmanned Aerial Vehicle power needs. 

now THAT I've gotta see!

[timdhawk]

What about this: 2 of the 6v ones below wired in paralell?
Is my thinking corret here: 2 6v's will give me 12v (that part i know) but will the Ah stay at 10 or will they double like the volts... and go up to 20Ah?

NP10-6   6v 10.0 Ah    5.95 x 1.97 x 3.84"   4.41 lbs   $ 22.00

[KingCustomCycles.com]

Series wiring increases voltage but NOT amp/hour capacity.
Parallel wiring increases capacity but NOT voltage.

What you are looking at is a series circuit with two 6 volt batteries wired to make a 12.  capacity will remain at the level of the individual batteries.  Thank you for the review, I used to teach that stuff in aircraft mechanics school and have since forgotten. 

[my78k]

King correct me if I am wrong on this but it will only perform at the peak of the weakest battery right? Sorta the weakest link analogy...

I mention this since the the battery life of running them in series would likely be less would they not?

Dennis

[timdhawk]

Series wiring increases voltage but NOT amp/hour capacity.
Parallel wiring increases capacity but NOT voltage.

What you are looking at is a series circuit with two 6 volt batteries wired to make a 12.  capacity will remain at the level of the individual batteries.  Thank you for the review, I used to teach that stuff in aircraft mechanics school and have since forgotten. 

thank you for that info!

King correct me if I am wrong on this but it will only perform at the peak of the weakest battery right? Sorta the weakest link analogy...

I mention this since the the battery life of running them in series would likely be less would they not?

Dennis

well, if i cant get the Ah i need then theres no point to running 2 together which takes me back to a regular 12v that is thinner than 3".

[KingCustomCycles.com]

The point of two may be that they could be located at different points on the bike.  I humbly suggest you move the location and go with a readily available 3" battery.  There is room under the transmission for example that is usually not as low as the pipes.  The pipes would still be the lowest point.  I put my batteries right behind the engine and about even with the transmission vent.  Tucked in tight and right side up so I can use a regular flooded lead acid.

[aussie]

Well voltage is always 12. if you are doing just lights and such, a 7 should be enough. Maybe even less if you switch out the incandescent bulbs for LEDs and the headlight for an HID setup.

Is this information on the money , i also have been looking at batteries and have found a really small gel battery that can lay on its side and is 8 amps.
I am loosing the starter and only running lights , hopefully it will do the job

[timdhawk]

The point of two may be that they could be located at different points on the bike.  I humbly suggest you move the location and go with a readily available 3" battery.  There is room under the transmission for example that is usually not as low as the pipes.  The pipes would still be the lowest point.  I put my batteries right behind the engine and about even with the transmission vent.  Tucked in tight and right side up so I can use a regular flooded lead acid.

might you have a detailed picture of this set-up?

[eldar]

If you have your charging system in good order and everything connected well, you should have no issues. You MAY need an electronic regulator but those are more efficient anyways.

On a different note, 2 batteries hooked like that will most likely die sooner. As you increase voltage, you decrease resistance and as such the plates will probably die sooner. As you double voltage, you halve your resistance. It is kinda like speakers. 2 8ohm coils together drop ohms to 4. Same principle more or less.

[KingCustomCycles.com]

pictures, we got pictures....

[KingCustomCycles.com]

You may get a few cranks out of an 8 AH battery which is all you need on a properly tuned bike.  You can always kick these old girls when in doubt.  I don't know what the absolute minimum is and suppose it depends on the individual bike.  The starter will cause a real drop in voltage on a small battery that the ignition may not like.  Slow crank + weak ignition = starting problems.  ( that was a math story problem) 

[eldar]

Yep, best off using kick on a small battery. my bike starts pretty good and I could probably do it but I would still do kick. If nothing else, you drop the weight of the starter.

[timdhawk]

pictures, we got pictures....

Moochus grassy ass!

Maybe i should clarify, my intent was not to run a smaller battery in power, only in size. I want stock battery abilities in the smallest package possible.
i have found a 12v 10Ah this size: 5.94" L x 2.56" W x 4.37" H
and the same but in 21Ah in this size: 7.14" L x 3.03" W x 6.59" H

however, from all the sites i've looked at (a lot now), 3" is about the "thinnest" i can get keeping within or above the 12-14Ah minimums.

[jonbuoy]

You will be fine running two 6volt batteries in series - as long as they are the same Ah capacity and the same age and there are no long cable runs between them.  In a normal motorcycle battery you have 6 x 2v cells connected in series inside the battery itself.  Trucks and boats normally use 2 x 12v batteries in series to give 24vdc.  Submarines used a few hundred in series/paralell.  The only time you'll get problems with series connecting batteries is when the capacities are different - one gets "full" before the other - one gets undercharged and one gets overcharged.

[eldar]

Difference is you are comparing to batteries designed to run separately to ones made to be combined. Of course it will work but the life will most likely be reduced and I doubt there would be any gains in anyway. More than likely the 2 6v batts will be just as heavy. There are more connections to pay attention too. If one needs to be replaced, it will be harder to figure out which one PLUS if one starts to go bad, it will put greater strain on the good one and shorten its life or cause it too die.  You talk about trucks using 24v, maybe it is an Oz thing but only semis and heavy trucks do that here and you are not just going to grab a battery off a shelf and use it. Many of them use a deepcycle batt which is constructed much heavier.
In short, it is made for that style of use. A small 6v batt is not.

So yes, it will work but I seriously doubt there will be any real benefit. There is more benefit from using a smaller AH battery.
Another thing is that when you raise voltage by doubling batteries, the power will be used up faster as resistance internally is dropped.

[jonbuoy]

Difference is you are comparing to batteries designed to run separately to ones made to be combined. Of course it will work but the life will most likely be reduced and I doubt there would be any gains in anyway. More than likely the 2 6v batts will be just as heavy. There are more connections to pay attention too. If one needs to be replaced, it will be harder to figure out which one PLUS if one starts to go bad, it will put greater strain on the good one and shorten its life or cause it too die.  You talk about trucks using 24v, maybe it is an Oz thing but only semis and heavy trucks do that here and you are not just going to grab a battery off a shelf and use it. Many of them use a deepcycle batt which is constructed much heavier.
In short, it is made for that style of use. A small 6v batt is not.

So yes, it will work but I seriously doubt there will be any real benefit. There is more benefit from using a smaller AH battery.
Another thing is that when you raise voltage by doubling batteries, the power will be used up faster as resistance internally is dropped.

No its pretty standard practice all over the world, all ships, boats, trucks, fire alarm backup batteries, UPS batteries, submarines even your torch at home has batteries in series.  A deep cycle battery is meant for deep cycling - ie being charged and then run flat nothing to do with being wired in series or parallell. It works.  Not sure how you can drop the internal resistance by connecting two batteries in series??  The battery is the source not the load.  I'm a marine sparky by trade and it IS standard practice.

[eldar]

It IS standard practice but in most of those cases, the batteries are designed for that purpose. An average battery is not. yes it will work fine but its life may not be as long. Plus you cannot deny the fact that if 1 goes bad that the draw is greatly increased on the other batt(s).

Also as for changing internal resistance, that is well known. FOR EXAMPLE: in ANY battery pack if you have 1 cell at 1.5 volts, lets say resist is 10 ohm and amps are 1. If you add another in series, you jump the voltage to 3, BUT your resist DROPS to 5 and amps stay at 1 HOWEVER; as the resist has dropped, power can flow faster and the battery will die sooner.
This is fact. Why do you think electricity is cranked up to high voltage to transfer? Resistance is lower and thus less line loss.
So my point is that a standard lead-acid batt is made to offer fair life when used in a steady state for which it was designed. It is not designed to be charged/discharged all the time. Also a powersupply, flashlights, backup batteries and such are NOT lead-acid. They are most likely a bi-metal based battery and as such, react differently than a chemical based battery.

Besides, for the sake of simplicity, drop the starter and get a smaller 12V batt.