Greetings, wondering if anyone can help me understand if this battery will do the job. First I thought cca or ah where the name of the game but then Duck said you might be able to run as low as 10ah. Then I found this battery which is relatively cheap and specs are low but in the description they claim it can start very big machines so now I am unsure. This is for a cafe racer I am building and no accessories will be connected(abs,gps,heated grips...). Thanks in advance.

Antigravity Batteries AG-SC-1 Battery https://www.amazon.ca/dp/B00VM7O6NC/ref=cm_sw_r_cp_apa_ODy5Bb7MJWZGW

I am successfully using a 12amp li-ion battery in Big Block. It's physically half the size of the 51913 battery that is commonly used in K bikes. No 'extra' electrical components are used on this bike. The battery cranks the bike over with gusto and the alternator charges it as intended. Due to a reduced reserve capacity, and your battery choice being only 5ah and 180cca, keep your charger handy if the bike is used intermittently.

To expand upon TWB's observation, here is a caution about use of that model by its manufacturer:
NOT RECOMMENDED FOR DAILY DRIVER TYPE VEHICLES!!!! It has a smaller capacity than recommended for regular use in street-only vehicles. USE for RACE.

First of all, thank you for both replies. Secondly, I have read the description thoroughly but your not answering my question, why* would it be good or not for a daily commuter, what makes a battery better suited to racing? Does it have to do with capacity like twowheels said? Just looking to understand better.

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marc.antoine124 wrote:...but your not answering my question, why* would it be good or not for a daily commuter, what makes a battery better suited to racing? Does it have to do with capacity...?

You're..it's you're, not 'your'.

Manufacturers make all sorts of hyperbolic claims about their product, but they're actually being honest in the small details. A battery used in a racing capacity will not have a demand placed on it for very far or for very long and can be easily charged between races, which may or may not occur on the same day. A battery used in a daily capacity has all manner of demand placed on it, so you're answering your own question. 5ah and 180cca isn't much reserve capacity for a Mighty K with its big lump of an engine in a cold climate; you will be asking a lot from it. Left out on the street for a day or three, will it crank the beast over after running three kilometres cross town to a cafe then back home again? That is why I recommend you keep a maintenance charger handy.

What TWB said. 

It seems that custom bikes just get parked outside bars, have photos taken and are hardly ridden more than a couple km at a time.  That kind of life is pretty hard on batteries, even worse than daily riding.  Long periods of idleness is hard on batteries and machinery, especially when that machinery is designed for frequent long distance operation.

Racing bikes on the other hand, lead a pretty plush life.  They are hardly ever outdoors when not on the track.  They are fussed over incessantly between races.  They are only run a few times a year with fairly long, well planned intervals between races when they are serviced.  Their batteries live on trickle chargers when they're not on the track.

Lithium batteries are, of course, very cool technology but in my experience AGM batteries are pretty good and reliable these days and beat the snot out of the old flooded lead-acid batteries. Even "half-sized" AGMs like an Odyssey 680 are lights years beyond an old full-sized battery in terms of weight, performance and reliability.

JM02

I'm with Duck. My one (really bad) experience with a lithium battery that died almost out of the box has meant I've stuck with AGM batteries since then. The battery was for my 600 Bandit and the f****g ebay seller accused me of overcharging it, despite me having bought a lithium charger from him at the same time. ebay refunded all, as it happens. I then bought an AGM and found it was barely larger than the lithium battery anyway.

Hi Dai guess your keyboard has run out of * with your response saying f****g ebay seller being being one * short to explain it fully.
Happy to send you 1x * to correct it and also send you a few more  ********** to use as spares or in need.

Allright guess I'll try AGM!

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I just installed a Shorai lithium battery in my K100RT. It was sized for a K1600 so is bigger than a K100 needs (it was in my 2011 K1600 that I traded in and it won't fit in the 2018 K1600)

I would not suggest putting in any battery that is so small as the one the OP wants to use.

At the prices I have seen for an AGM battery it is not all that much extra to get a lithium battery these days.

Battery choice also depends on where you are as in a very warm or very cold place. If bike is left in a frost all day and then expected to crank a cold engine you need a decent battery. Low temperatures play havoc with a battery.

The K spec seems to have varied from 20 to 30Ah, depending on whether its an early K100 or a late K100LT. Engines are same but the LT has a lot more gadgets that draw power.

Another thing that can impact the amps available for starting is having the headlight turned off.    Yes, the load shed relay will turn off the headlight during starting but the headlight draws power before the start button is pressed.

I didn't believe this until a friend of mine demonstrated it to me on his K75 with a Euro switch.  

US bikes did not come with a headlight switch and always have the headlight on. I always install a Euro switch on Ks that I buy.

Here's what a US right combination switch looks like:

Thank you all for your replies!

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duck wrote:Another thing that can impact the amps available for starting is having the headlight turned off.    Yes, the load shed relay will turn off the headlight during starting but the headlight draws power before the start button is pressed.

I didn't believe this until a friend of mine demonstrated it to me on his K75 with a Euro switch.  

US bikes did not come with a headlight switch and always have the headlight on. I always install a Euro switch on Ks that I buy.

Here's what a US right combination switch looks like:

So if I got this right, the relay box will only disconnect the headlight when the starter turns the engine over. What your saying is I would need to install an other switch to make sure the headlight is disconnected when the bike is not running?

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marc.antoine124 wrote:What your saying is I would need to install an other switch to make sure the headlight is disconnected when the bike is not running?

What duck seems to be saying is if your battery is in poor condition, having a switch to keep the headlight shut off when starting might provide just enough extra current to start the moto.

If your battery and charging system are in good condition you shouldn't need a headlight shutoff switch. The ignition switch in the Off position should shut down the engine and disconnect both the parking light and headlight.

In fifty thousand miles, the six year old battery in my K75 hasn't had any trouble starting. The load shed relay in the relay box has always cut the headlight current quickly enough to provide plenty of current to start the engine in temperatures down to 17ºF. I prefer having the headlight turn on automatically and riding with it on.

Laitch wrote:

marc.antoine124 wrote:What your saying is I would need to install an other switch to make sure the headlight is disconnected when the bike is not running?

What duck seems to be saying is if your battery is in poor condition, having a switch to keep the headlight shut off when starting might provide just enough extra current to start the moto.

No, you don't need to add another switch.  Just pointing out that if your battery is low or getting old that turning the headlight off will increase your odds of starting the bike.

Since I have several bikes and some don't get run that often I turn the headlight off before trying to start them.  If I know the battery has a good state of charge then I don't bother doing that.

Some light reading if your curious, I'm really impressed with my battery, left it for 2 months and worked perfectly.

https://www.k100-forum.com/t13576-is-this-battery-powerful-enough

Headlight off AND pull the clutch. Both place a load on the battery. At 60W plus a 10W rear light and a 3W warning light that's 6amps. Agreed the load shed relay cuts it but that's AFTER the headlight has started to draw current.

Pulling the clutch means no clutch and transmission drag when starting.

In very cold or marginal conditions this does make a difference.

DBRMN wrote:Some light reading if your curious, I'm really impressed with my battery, left it for 2 months and worked perfectly.
https://www.k100-forum.com/t13576-is-this-battery-powerful-enough

You have giving a positive review of your moto's battery, DBRMN and have referred readers to a discussion of battery quality but none of what I read seems to reveal which battery you finally installed.

What is the make and model number of the battery that you bought which has impressed you by not discharging after two months? Did you disconnect the battery's ground cable before it remained idle for that period of time?

Laitch wrote:

DBRMN wrote:Some light reading if your curious, I'm really impressed with my battery, left it for 2 months and worked perfectly.
https://www.k100-forum.com/t13576-is-this-battery-powerful-enough

You have giving a positive review of your moto's battery, DBRMN and have referred readers to a discussion of battery quality but none of what I read seems to reveal which battery you finally installed.

What is the make and model number of the battery that you bought which has impressed you by not discharging after two months? Did you disconnect the battery's ground cable before it remained idle for that period of time?

Sorry I got the Antigravity Battery AG1201, I did disconnect the terminal.

Hi Marc.  I initially put a Shorai lithium into a project I built for a friend.  Within a couple of months it started giving me grief, unable to hold a full charge etc.  It eventually shorted out completely internally and got massively hot an began to spew noxious fumes and overheat - while sitting in the garage.  If I had not come out to check something else on the bike there would have been a fire for sure.  So I would NEVER recommend a Shorai.  I replaced it (under warranty!!)with an AntiGravity battery and all is well.  YMMV.

club_c wrote:Hi Marc.  I initially put a Shorai lithium into a project I built for a friend.  Within a couple of months it started giving me grief, unable to hold a full charge etc.  It eventually shorted out completely internally and got massively hot an began to spew noxious fumes and overheat - while sitting in the garage.  If I had not come out to check something else on the bike there would have been a fire for sure.  So I would NEVER recommend a Shorai.  I replaced it (under warranty!!)with an AntiGravity battery and all is well.  YMMV.

One bad Shorai does not mean the millions of good ones out there are bad too.

BobT wrote:

club_c wrote:Hi Marc.  I initially put a Shorai lithium into a project I built for a friend.  Within a couple of months it started giving me grief, unable to hold a full charge etc.  It eventually shorted out completely internally and got massively hot an began to spew noxious fumes and overheat - while sitting in the garage.  If I had not come out to check something else on the bike there would have been a fire for sure.  So I would NEVER recommend a Shorai.  I replaced it (under warranty!!)with an AntiGravity battery and all is well.  YMMV.

One bad Shorai does not mean the millions of good ones out there are bad too.

I agree. Products of all kinds suffer failures. No product is perfect.

I have a 4 year old Shorai in my RT

I have to agree that a once-dubious reputation shouldn't be enough to spoil a product for evermore. About six years ago I worked in a large, metropolitan Beemer dealership which sold Shorai products. Initially, they had a lack of durability due to what was at the time, of having too small of a rating for each individual model listing they were spec'd for. We returned heaps of them. Failures left and right, although some would have been because - gasp - a majority of owners expect a battery to last a Winter with little or no maintenance.

It took Shorai two or three goes to get their catalogue corrected and model line-up sorted and up spec'd. They did it. Nowadays they are rated a top tier lithium battery seller, with good result. The latest company I worked for, and from which I recently parted, is a wholesaler of Shorai, and I can say unequivocally that it was their best selling battery, lithium-wise. This is my experience and I am not beholden to anyone about the product, don't currently use them personally, and wouldn't have to give it a second thought if I did use one.

Full props to Bob and TWB. I shared my experience because of the severity of the failure. I was only a few minutes from a full on vehicle fire and likely structure fire if not for divine intervention. In my situation it was not merely a breakdown or part not fitting correctly but a significant risk of property loss and threat to personal safety. That’s why I wouldn’t recommend it to my friends. There are other good options out there, they’re not the only game in town. Maybe they have resolved the reliability issues, but my story is from April 2018.

club_c wrote:Full props to Bob and TWB. I shared my experience because of the severity of the failure. I was only a few minutes from a full on vehicle fire and likely structure fire if not for divine intervention. In my situation it was not merely a breakdown or part not fitting correctly but a significant risk of property loss and threat to personal safety. That’s why I wouldn’t recommend it to my friends. There are other good options out there, they’re not the only game in town. Maybe they have resolved the reliability issues, but my story is from April 2018.

I am sure that over the last 40 years there has been a severe failure of something critical on a BMW K100 that either did, or nearly caused loss of life. That one failure should not put everyone off riding a K100.
The trouble with forums and the internet is that one person has a problem and spreads it around. The other 50,000 people who have the same product and have no problem say nothing. Then 20,000 people who have a rival product highlight the one persons problem to justify buying the rival product. It won't take long for the first product, with a failure rate of only 1 in 50,000, to become unpopular.
I understand that you have a 100% failure rate with that particular Lithium battery, but that company produce thousands of them with a problem.