• Welcome to the BMW R18 Forums. Member registration disables ads and allows you to post and share. Register Here.

BMW R18 battery

  • <i class="fa--xf fal fa-check "><svg xmlns="http://www.w3.org/2000/svg" role="img" aria-hidden="true" ><use href="/data/local/icons/light.svg?v=1768230793#check"></use></svg></i> Discussion starter Discussion starter beemerbanjara
  • Start date Start date
B

beemerbanjara

New member
Joined
Jan 25, 2025
Messages
12
Location
Los Angeles
Visit site
Bike
bmw r18
Hi everyone,
I was getting the battery with ? logo and the bike would not start. Once I used the jump started, it turned on like butter- A day later it did not charge. So, yesterday I took the battery out ( side note: it was only 3 screws and the battery comes out quite easily compared to 114 M8 harley) and I charged it.

Should I do any recommended test to see if the battery is still hanging in there? or just buy a new one? FYI- I also ordered an entry level millimeter from amazon-


Bike
2021 R18

Any advise is much appreciated-
 
I’ve had motorcycle batteries last five years and some go at two. The original OEM batteries tend to go first. The bikes sit around for long stretches and the batteries likely discharge fairly often requiring a charge to bring them back. Not so good for the health of the battery.
Based on your description, I’d say it’s time for a new battery.
 
Stay away from lithium batteries. They have an unacceptable failure rate.
A good name brand AGM battery should be fine.
I just bought a Duracell AGM from Batteries Plus for my wife’s Chieftain.
 
MilwDave said:
Stay away from lithium batteries. They have an unacceptable failure rate.
A good name brand AGM battery should be fine.
I just bought a Duracell AGM from Batteries Plus for my wife’s Chieftain.
Click to expand...
I was thinking of going to a Li type battery when the time comes to replace the AGM on my R18 B; the used FE that I purchased this past Summer, already had a Li battery installed. It seems to work well and has been holding it's charge during the long idle periods. I may configure my trickle charger for Li and move it off of the B and over onto the FE Project bike and give it a couple of days to recharge.

Is there a high quality Li battery manufacturer that might not be subject to failure? I think BMW sells Li batteries for a handful of their models that come stock with a Li battery?
 
Star-Lord said:
I was thinking of going to a Li type battery when the time comes to replace the AGM on my R18 B; the used FE that I purchased this past Summer, already had a Li battery installed. It seems to work well and has been holding it's charge during the long idle periods. I may configure my trickle charger for Li and move it off of the B and over onto the FE Project bike and give it a couple of days to recharge.

Is there a high quality Li battery manufacturer that might not be subject to failure? I think BMW sells Li batteries for a handful of their models that come stock with a Li battery?
Click to expand...
Here’s my experience for what it’s worth.
4 years ago I tried a Shorai lithium and it failed after 3 months. I got a replacement under warranty and sold it. Last summer I bought a NOCO lithium for my wife. After 6 months it failed. NOCO sent me a replacement under warranty. That one was DOA. I replaced it with a AGM because it is for my wife’s bike and I can’t have her getting stranded with a bad battery.
NOCO is sending me another replacement and this time it’s going in my FTR that doesn’t get ridden as often. We’ll see how that goes.
At this point I’m going to stick with AGM in all my bikes. But in another 5 years, who knows?
 
I have a 23 Anniversary model. I already swapped out the factory battery for a Lithium. I ride canyons and I don't want a problem ever starting the bike. Could be my imagination but the bike runs better...
I've been using Lithium batteries in my other BMW and Harley, never had a problem, effortless cranking power, hold a charge a long time....
 
beemerbanjara said:
does it make a diff that my oem battery says 26Ah and this one here is 18Ah?
Click to expand...
Lithium iron phosphate batteries stay powerful over a ton of cycles whereas the lead acid quickly diminish. I'm not sure what the power requirement of the R18 electrical system is, but apparently 18ah is plenty. I'm sure your old lead acid oem battery if measured now or even six months ago was nowhere near where it started out at 26ah. Lead acid weaken quickly where LiFeOr4 batteries are described as energy dense and long lasting.
 
Boritch said:
Lithium iron phosphate batteries stay powerful over a ton of cycles whereas the lead acid quickly diminish. I'm not sure what the power requirement of the R18 electrical system is, but apparently 18ah is plenty. I'm sure your old lead acid oem battery if measured now or even six months ago was nowhere near where it started out at 26ah. Lead acid weaken quickly where LiFeOr4 batteries are described as energy dense and long lasting.
Click to expand...
The BOS is what typically fails in lithium motorcycle batteries.
 
Man, I've had two Shorai batteries and both have worked great, outside of needing to warm them up below 45 degrees. The one was in a V-Rod, I had it 6 years with the Shorai, sold it to a buddy, and the battery was still working when he sold it a couple years later. Impressive longevity.

The other one is in my 1200 GSA and I've got 5 years in it so far and still working well. Curious how long I will get out of it.

Now, I do have the Shorai charger I use a couple times a year, that may help. Not sure. Both bikes I used it in got / get ridden pretty regularly.

Sorry you had a bad time with them. My R18 battery is going strong (2021 demo model) but I do need a battery in my Triumph this spring and I'm likely going Shorai in it.
 
PistolPeteSTL said:
Man, I've had two Shorai batteries and both have worked great, outside of needing to warm them up below 45 degrees. The one was in a V-Rod, I had it 6 years with the Shorai, sold it to a buddy, and the battery was still working when he sold it a couple years later. Impressive longevity.

The other one is in my 1200 GSA and I've got 5 years in it so far and still working well. Curious how long I will get out of it.

Now, I do have the Shorai charger I use a couple times a year, that may help. Not sure. Both bikes I used it in got / get ridden pretty regularly.

Sorry you had a bad time with them. My R18 battery is going strong (2021 demo model) but I do need a battery in my Triumph this spring and I'm likely going Shorai in it.
Click to expand...
Well I’m pretty certain no product has a 100% failure rate. But a battery that just quits and then won’t accept a charge (which is what happens when a BOS failure occurs) is too risky for the type of riding we do.
 
First appreciate the help from the community. I charged the battery using a tender and that was sunday night. Today is tuesday night and used the mm to check the voltage and it shows 12.4V .

Should i wait a few more days and check voltage again to see if the battery has really gone bad?
 

Attachments

  • 20250128_163410.jpg
    20250128_163410.jpg
    1.5 MB · Views: 9
beemerbanjara said:
First appreciate the help from the community. I charged the battery using a tender and that was sunday night. Today is tuesday night and used the mm to check the voltage and it shows 12.4V .

Should i wait a few more days and check voltage again to see if the battery has really gone bad?
Click to expand...
Nope, it’s done and you need a replacement.
A healthy battery should charge in a few hours to 13.4v.
 
You must log in or register to reply here.
Back
Top