Hello everyone Im looking to replace the battery on my 87' K100rs , it seems that as soon as I enter the word BMW when searching the price doubles , I know is nothing magical about our batteries , so what can I use for under U$100 ?? looking for something decent but dont need to have the latest battery on the market , also it has to be something that I can get in the US. Thanks
PS: Mine says 30AH , does it has to be a 30amp battery? not sure if the PO just install what ever he found.

That is the standard size Chris. Many sizes fit and the thing to make sure of is that the height is correct because the long screws dont have any extra to play with.
I use a gel battery in all my Ks they are maintenence free and supply a good wack of current when you hit the button. I have no personal experience with the length of service as all mine are under 3 years old but I know of several people who have got 5 or more years out of one. They are a bit more expensive but do last so the cost is really good if you take it like that.
Check this one out http://www.ebay.com/itm/UIX30L-YIX30L-BS-BMW-K100S-K100RT-1000-R-R100CS-Battery-/130511178937?pt=Automotive_Services&vxp=mtr&hash=item1e63128cb9

Check Deka (East Penn Manufacturing Oc)

This is what I use for the last 5 years.

CF

After replacing many batteries over the years and , like you, mentioning BMW I came up with a cheaper solution. Take your battery out and take it to a trustworthy battery place. Place battery on counter and explain that the battery is stuffed and you need a replacement. The blokes here measured the battery, checked the specifications and produced a battery from out the back of the store.

Apparently the cross reference charts do not always line up amongst the manufacturers and the BMW name suggests wealth, therefore price hike.

So work from the battery, rather than the bike.

true that ainsjac ...i got mine for $85...

ainsjac, I just ordered a battery from here http://www.batterystuff.com/powersports-batteries/sYIX30L.html Ordered it on Monday and it arrived today, no tax and free shipping. Hope that helps.

Sorry, that was supposed to addressed to Cris_A

Bert ... did you get that Deka battery in Halifax or did you import it? Which model #? Ken

CaperKen wrote:Bert ... did you get that Deka battery in Halifax or did you import it? Which model #? Ken

I got the ETX16L from East Penn on Ackerley Blvd in Burnside.
Here are the specs and price
It is a bit physically smaller, but they provide a spacer and the battery fits perfectly.

CF

Thanks, Bert. I'll need a new one in the spring. Ken

Thanks to everyone the Deka is looking good , but as long as the battery is 30amp and it can fit I can just get anything , guess the key part is the 30amp

No one answered if it needed to be a 30amp battery...

martyman wrote:No one answered if it needed to be a 30amp battery...

Yes it has to be 30A.

My K100LT battery died on a Friday up in the west of Ireland. Not in a million years could you get a battery there...or so I thought.

On the back of my son's bike, battery in hand, we headed tot he nearest Halfords at the next big town about half an hour away, only to discover this branch did not sell motorcycle batteries. 'Try up the road, there is a place sells ride on lawnmowers, he might help'.

So off we went. I duly placed the battery on the counter and sheepishly asked 'you wouldn't happen to have one of these?' Without moving he lifted a box out from under the counter and said 'like this?' Exact match size, not being in a position to refuse I took the 20mp battery for the princely sum of €50. Fitted in the LT it ran perfectly for3 years and more.

All I wanted was one to get me home but it did the job again and again. Seems the RT only calls up 20 Amp......so the difference must be to cater for the accessories. Engine, starter, lights etc are all identical.

However, in times of trouble that extra 30 Amp over 20 Amp is worth having.

My yuasa 53030 will still start my bike up but will not fully charge...would like to find a replacement that is not a pain in the butt to take in and out...that is why I was curious if I could use a slightly smaller width battery with less Amps...thank you.

martyman wrote:My yuasa 53030 will still start my bike up but will not fully charge...would like to find a replacement that is not a pain in the butt to take in and out...that is why I was curious if I could use a slightly smaller width battery with less Amps...thank you.

As I said earlier in this thread, the ETX16L is a bit physically smaller, but they provide a spacer and the battery fits perfectly.
It's very easy to pull this battery out.

Thank you I will try to find one of those...


DEKA is 19A

My K100 has an EXT15L. It saves pounds of weight and $$$.

I would only recommend it though if you plan to keep the bike on a tender or plan to ride it at least once a week or so. If kept fully charged, it starts the bike just fine.

http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/batts/batteries.htm

Just clarifying, 30AH (not 30A) means it will deliver 30 amps for 1 hour before it's flat, or 1 amp for 30 hours or any other combination of amps and hours that multiplies to make 30. 
It's a measure of the amount of electrical energy stored in the battery. 

The other important measure for a battery is CCA or cold cranking amps - the maximum current that can be delivered for starting the engine. Engines vary in how much much they require, but my Haynes manual doesn't have the figure for the Ks. Batteries vary in how much CCA they can deliver, too. Not always related to AH or size.

Normally, you only use a fraction of the energy in the battery to start the engine, then the alternator takes over the job of supplying all the electricity for running the engine and all accessories, as well as recharging the battery.

The extra battery capacity is to allow for multiple starting attempts if necessary and running accessories (lights, phone chargers etc) while the engine is not running. It also runs the engine etc for a time if the alternator fails while riding. It will also take up the slack to a degree if you have something temporarily attached which lifts demand over the alternator's delivery capacity. If you do that a lot, you need a bigger alternator. e.g. driving lights

In most cases, a much smaller battery is all that is needed, but a larger capacity battery gives the extra insurance for those multiple starting attempts or running accessories while stopped. A smaller battery may also not deliver enough CCA for the engine.
If you go for a smaller battery for weight, availability or space reasons, it will be OK if it delivers enough CCA, but you take the risk for multiple start attempts, etc.

Bill

PS following Duck's contribution.
A larger battery will also likely still have enough charge to start an engine if it goes down a bit by non use or non charging over time. Another insurance factor of the larger battery, but keeping it on a maintenance charger or using more frequently will limit the risk, as Duck says.

I'm on my third Motobatt MB51814 (in various Beemers) now. It's an AGM rated at 260 CCA and is a 22Ah. It's the slimmer version of the two that fit K75/100/1100 & Brick 1200, and has both positive and negative terminals at each corner for multiple applications, though it's intended for and fits BMW K and Oilheads as an OEM does.

Here are the specs:

MotoBatt MB51814 Sealed AGM Battery Specifications

Model

Ah

CCA

L x W x H (inches)

L x W x H (mm)

Spacer Height

Total Heght

Total Terminals

MB51814

22

260

7.20

3.15

6.69

183

80

170

na

na

170 mm

6.73"

4 QuadFlex

The Ks don't need a big battery for starting and many of the K75 and K100RS had 18AH as standard. Most of the RT/LT had the 30AH because they were the authorities bikes and needed the bigger battery for the flashing lights and high power radios.AFAIK the LT in Oz had the 30AH as standard but the retail version of the RT was optional.
I have a large battery because I need to run a CPAP machine when camping and some extra lights.
The battery cradle has provisions for both sizes. Actually the large battery that was used was a 24AH not 30AH but with the AGM batteries now a 30AH can fit.

If I could only have one battery it would be the Odyssey PC680. They LAST and in my experience are extremely reliable.

My experiment with the EXT15L was just to see how small of a battery I could "get away with."

Westco's weigh a little more than the PC680 but are also a "tank" of a reliable battery with a well-deserved excellent reputation. If I were to do a RTW or similar I would probably start with a fresh Westco.

Hello!

18 Amp is enough for the K.
I take the Kung long build for the solar industry or alarm systems.
Last the last 4 years and starts perfect, even with ABS, witch is quit sensitive for low power.
I prefer a stronger Alternator 50amp

The best price on the market.

Kung-Long-WP18-12-12V-18Ah-UPS
Or
Kung-Long-WP22-12-12V-18Ah-UPS

http://www.ebay.com.au/itm/Kung-Long-WP18-12-12V-18Ah-UPS-Battery-/281342287045?hash=item41814e9cc5:g:jGsAAOSw-jhULdM5

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Cheers

I'll concur with the opinion that 18AH is sufficient. My K75 came with a Yuasa YTX20HL-BS 18AH battery when I bought it used from a guy who didn't ride any more. So, he had that battery in the bike, stored in the garage, for a year or two prior to selling.  I've used the same battery reliably for three years ever since.  It has 310 CCA which is enough to get the K75 engine turning over briskly.

Battery threads can sometimes seem a bit like oil threads in that riders can have varying experiences with the same battery.  Case in point: I have an Odyssey PC680 in a non-BMW bike that is about 10 years old.  It must be one of the best batteries I've even had. That battery has an extremely slow self-discharge rate.  I subsequently bought others (PC680) and both failed within 2 or 3 years.  My experience with these batteries suggests that quality control is inconsistent.  
My K100RS now has a Deka full-sized battery I bought from EME.  It's only one year old but seems to be a solid item, with a self-discharge rate I can live with.  
I parted ways with flooded cell batteries years ago.  Topping up those cells and the invariable acid etching of the bike are things I no longer worry about.

If you let a K bike sit, the clock will discharge the battery quicker than "self-discharge." It's a very small current but over several months it can drain the battery.

If you know the bike is going to sit for a while then it's a good idea to disconnect the battery ground.

I let my K11LT sit for a year in storage (Panasonic large 20A battery.)  Hooked the ground back up and it started right up.

Maintenance is mandatory for any batterie!
I don't want any acid batterie, destroys my frame and needs water.

Avery first of the month I charge my batteries, winter and summer.
Prevents from discharging.

To disconnect the batterie I use this for 3€
It is connected to the ground cable to the gearbox
It also prevents/helps in case the starter is sticking.
The ground/batterie connection is interrupted.

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Cheers

Although I usually disconnect the battery ground if I know a bike is going to sit, upon further reflection, a simpler approach might just be to remove the unswitched Fuse #3 which powers the clock.

Chocolate wrote:Maintenance is mandatory for any batterie!
I don't want any acid batterie, destroys my frame and needs water.

Avery first of the month I charge my batteries, winter and summer.
Prevents from discharging.

To disconnect the batterie I use this for 3€
It is connected to the ground cable to the gearbox
It also prevents/helps in case the starter is sticking.
The ground/batterie connection is interrupted.

" />

" />

Cheers

SLA (sealed lead acid) batteries do not leak acid, even if installed upside down, and require no maintenance.

I installed anderson plugs on my K1100 and my wifes K75. It makes it easy to unplug if I am working on the fuel system or if the starter relay did it's trick.

Excellent info, have a line on a Deka thank you...


Found one from this place that is very close to where I live...good price also

http://www.motorcycleinnovations.ca/ETX16L_p/etx16l.htm

An anderson plug is what? 

This

I've got them fitted on my earth cable.

"It makes it easy to unplug if I am working on the fuel system or if the starter relay did it's trick." Exactly.

Oh...and for what it's worth, my 18Ah golf buggy battery is on its 4th year of service.