79 XS11 Battery?

[Bodi]

Hey,

Brand new guy. I recently picked up a 79 xs11 that had been cut pretty badly from the rear back. All that was left was the engine cradle forward, and the rear swingarm/shaft drive. It was a bobber project that had stalled, and was in danger of finding its' way to the recycling bin. I have since done a hardtail on it mounting to the stock shock location. I understand the stance on a forum like this about cutting up a beloved motorcycle, and I want everyone to know that I am experienced in doing this sort of thing. I understand that this thing will be an ill tempered nasty riding machine, and I do not have any illusions that I am going to hop on and head across county.

That being said;
I have the stock SIZED (cheap Walmart Everlast) battery, and it is FAR too large for the battery location now that it has been hardtailed.

The battery I have has NO numbering on it for me to cross reference. I need to know the battery part number, or the specifications of the battery so that I can find something capable of handling the cranking/reserve but in a much smaller more modern package.

If you guys could help me find the stock battery number, or the stock batteries specs it would help me on my way to getting my battery box made, and getting this thing back on the road.

This started life as a 79 XS1100 standard
Thanks a ton.

[bikerphil]

Copied this from somewhere a while back, I hope it is somewhat accurate,

Battery Cross Reference: Champion 18LA2, Energizer 02420200, GS (JSB) GM18Z-3A(S),
GS (ZYI) C50-N18L-A3, Motocross M2218Y / M3218Y / M228A3 / M328A3, Napa
740-1855, Sears 44359, Wal-Mart ES50N18LA3, Yacht C50N18L-A / C50-N18L-A3, Yuasa
Y50-N18L-A / Y50-N18L-A3, Powersonic PTX18L-BS, PowerSonic PIX50L-BS, PowerSonic
PIX50LBS-FS, PowerSonic C50-N18L-A-LM, Odyssey PC680 Cross Reference: Deka ETX18L, GS (ZYI) GTX18L-BS, Napa, 740-1889, Sears
44006, Yacht CTX18L-BS, Motocross M6250H / M7250H / M2218C / M3218C, NAPA
740-1889, SEARS 44006 / 44030, Yacht CTX18L-BS / CTX24HL-BS / C50-N18L-A-LM,
Yuasa YTX24HL-BS / Y50-N18L-A-CX

[DGXSER]

If I recall correctly, T99Ford put a very small battery in an XS11 or something similar. This battery was REALLY small.

[natemoen]

If I recall correctly, T99Ford put a very small battery in an XS11 or something similar. This battery was REALLY small.

No that battery was in his sport bike. There was just a thread discussing how a shorai battery wouldn't work in the XS because of the inconsistent charging system.

http://www.xs11.com/forum/showthread.php?t=33215

[clcorbin]

I have ordered some A123 cells to build up my own battery for my 79F. My problem is I need the space where the current battery is for a header tank (eventual fuel injection conversion). I will be able to build up a "stick pack" that is only a little over 1" tall, by 1 1/2" or so wide and a bit less than 9" in length. The A123 cells are a LOT more durable than standard LiPOs, so I'm not worried about them going up in flames or anything.

I am also looking into building a digital regulator to maximize the power from the stock alternator. Hopefully, it will all be enough to power the FI system, along with the help of the LED conversion.

[crazy steve]

Well, in the 'spirit' of the hardtail conversion, if you fit a permanent kicker to it (that has issues too, but I won't go into those! ) so you don't need the big starting current, you could fit pretty much any 12v battery.

[Bodi]

I've been looking into possibly using a Bat-Cap for this application. One I have found is 3.5" x 3" x 4". FAR smaller than the stock battery. It doesn't have the reserve that a battery would have, but, specs out to 400 peak amps for 8 seconds. That should be enough to crank over a well tuned 1100. I would hope to have it tuned well enough to not need over 8 seconds of cranking.

Crazy Steve,

I've looked into mounting a kick starter. I have one from an XS850 that came with the bike, but, it looks like drilling and tapping would be required for a permanent mounting.

As far as the smaller batteries, what would be the problem with running anything much smaller? I'd figured that alot of more modern batteries would be up to the task. I know that the battery in my dad's Road Star is far smaller, and is cranking a 1600 v-twin that I'd imagine has far more compression. I would think there would be plenty of more modern batteries out there that would have even better specs as far as Amp hrs, and cca.

If anyone would care to, please enlighten on what problems I may encounter running a smaller battery if I can find one with similar specifications.

Thanks in advance.

[natemoen]

The XS charging system is very inconsistent and because the shorai Li-Pho battery needs a very consistent and steady charge it just would not last in the XS system. I would imagine that would be the same with most li-pho batteries.

Even with the capacitor you are talking about, better do your homework on it. The XS is not charging really at all under 2000rpm so of you are sitting at a light how long will your cap last?

[cywelchjr]

+1 on the insufficient charging system. At idle you need enough capacity to run the bike as the battery is discharging at that point and the headlight, taillight and ignition system is actually running off the battery with the charging system just slowing down how fast it's running down a little bit. I doubt that a batcap would have the capacity to handle much if any idling, as it would be expecting the bike to be able to run without a battery and these bike will NOT run without the battery, not only will it kill the charging system (which I'm sure the batcap would prevent as it would provide the damping load for the charging system) but below about 2500 RPM in stock form the charging system doesn't provide enough voltage to run the bikes systems.

This is unlike other bikes I have had such as my old Honda CL360 which would run and even start without a battery, but it had a system that actually took half the stator windings (or maybe more I forget) out of circuit when the headlight was turned off to prevent overcharging.

[crazy steve]

.. I'd figured that a lot of more modern batteries would be up to the task. I know that the battery in my dad's Road Star is far smaller, and is cranking a 1600 v-twin that I'd imagine has far more compression. I would think there would be plenty of more modern batteries out there that would have even better specs as far as Amp hrs, and cca..

Lead-acid batteries really haven't improved all that much over the years, in spite of the advertising claims you may see. It's still the same old chemical reaction, and while there's been improvement in how it's 'packaged', you still pretty much need 'X' amount of plate area for a given output. There have been improvements in starter motor design/efficiency, so that probably explains the smaller battery you're seeing in some bikes. Or the willingness of the manufacturer to cut corners on the design...

Yamaha didn't give 'full' specs on the OEM battery (at least that I ever saw), merely noting that it was 20 AH, so your best bet would be to look up current specs on a stock replacement. It has been noted that the stock XS starter draws roughly 90 amps while cranking if everything is working right, but if anything gets a bit marginal, that can go up pretty fast. I'd look for the least-expensive one you can find, as that will probably give you an idea of the minimum CCA needed. Then see if you can find a suitably-sized smaller battery that can deliver the same. But to be honest, unless you go to a 'exotic' type like the Shorai, I don't think you'll see any huge difference...

[crazy steve]

...I've looked into mounting a kick starter. I have one from an XS850 that came with the bike, but, it looks like drilling and tapping would be required for a permanent mounting..

Not quite a bolt-on, but to use that 850 kicker all you need to do is file/grind a notch in the lever shaft for the clamping bolt. It can get very close to the stock sidecover when folded, some guys have bent the arm slightly, some haven't. That part is the best choice for a permanently installed kicker...

[oldnortonrider]

.........help for battery and charging system

Long years ago I installed separate off/on switch for the headlite; I turn it to OFF when I'm trying to start it. Without the switch, if the engine even coughs, and doesn't catch~~headlite will come on. Sure, you can turn the key off, and back on, to get headlite off; but you'll go nuts doing this during a difficult starting session. Separate switch; it works. ALSO, a switch to turn the taillite off. Stoplite is separate electrical. You don't need the taillite burning and drawing juice during daylight hours; leave it off except when things "darken". Starting with taillite off and headlite off will help one to have a happier battery~~not to mention easier starts. Here's something else that one can do if one doesn't want the hassle of putting the separate switch for the taillite;~~ if you're running daylight hours only~~mostly~~you can pull the taillight fuse. Not too handy if you've got the glass type fuse(s)~~best, by far, with blade type fuse block. If you make a run in the dark, ever few months~~put the blade fuse back in for the taillight.