Is my battery weak?

I

insomnia

Active member
2022-r18.b
I have a brand new R18B FE sitting in the garage. I haven't even ridden it yet, waiting for spring. I have a Ctek charger connected to the positive terminal and the ground terminal under the cylinder.

But the battery never gets better than 12.9V read from the LCD panel on the bike itself with ignition on, engine off, charger still connected. It decreases to 12.4V within 30-60 seconds. This must be too low for a new bike/battery?

I recently saw a picture here on the forum of a TC LCD panel where it said 14.2V, and I think it was with engine off too. My battery should be up there, shouldn't it?
 
What does the battery voltage read when the bike is idling? If you have a volt meter, maybe see what the charger is putting out voltage wise, also measure the battery voltage off the battery.
 
The bike is in a closed room for the winter, so I cannot start it just now.

Don't have a volt meter. I have thought to acquire one, but have no idea of the requirements for a reliable/good one. Are cheap ones any good? The ones you connect to the outlet on the bike, are they any good?

To measure off the battery accurately, could you connect the same way as I connected the charger, i.e. to the positive terminal and the ground terminal under the cylinder?
 
If buying a VOM, I have a Fluke which is a great tool to have around the house, as well as the garage.

Your bike could be reading the float voltage that the trickle charger is putting out to maintain the battery charge.

The alternator typically puts out a higher voltage in order to restore what depleted energy was used to start the engine; typically 13.8 V DC is a general number - but based on what others are seeing, I guess as high as 14.2 V DC.

A couple of us are thinking of sneaking out for a 50°+ weather day tomorrow, I'll take note of what my B model reports in terms of voltage while sitting on the trickle charger, disconnected prior to starting and while on the road.
 
Thanks, it would be great to have your voltage for comparison.

I'll also check my voltage without the charger connected as soon as I can. Bike is located at work for winter, and right now I'm home from work with a severe cold.
 
insomnia said:
Thanks for the pic, it seems we have similar voltages. But you have a faster bike, capable of 200 mph...! :ROFLMAO:

And I found the pic I was referring to here: https://www.r18forums.com/threads/2022-r18-transcontinental.1819/

To me it seems that it shows 14.2V with engine off, perhaps @R12C-R18TC can confirm or correct?
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As was my R18

I would have much rather had a US spec one that went to 130mph but I believe there is some old regulation here in the UK about being able to display mph/kph.


About 1:20 in this vid scrolling through the menu shows over 14v running.


About 7:30 in this one 12.6 not running.
 

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Thanks for checking your bikes. Since we have similar voltages with engine off, my battery should be ok.

What's still nagging a tiny little bit is that I've heard that AGM batteries should measure higher than regular batteries, or perhaps that the charging voltage should be higher. I'm not sure what I've heard, anybody know something about it?
 
I trust that the trickle chargers do as advertised and optimize the proper voltages necessary to maintain my motorcycle battery for at least 5 years; owning an RV and upgrading and maintaining the DC plant, I've come to learn that there are many different energy storage chemistry types.

I'd be willing to bet your motorcycle battery and charger are fine; there's many different rules that folks follow when maintaining their motorcycle. My bike isn't a daily commuter, so I plug it in after each ride and leave it plugged in; I don't remove the battery either over the Winter, but do keep it connected to the trickle charger. I've had great luck with an older GS Adventure (2008), where it's stock battery was replaced only once and the bike logged over 96,000 miles.. following my above mentioned regiment.

My GS used a BMW brand trickle charger and I now have my R18 B connected to the newest BMW smart charger ( I think it can accommodate Li batteries, if equipped).

Funny... I had to jump start my buddy's HD before heading off to a ride yesterday; he swears that it's bad for a battery to be left on a trickle charger... Again, I trust the newer trickle chargers have some intelligence behind them these days..
 
14V is what comes out of the bike's charging system. The battery tender charges at 12. The battery by itself will never output more than 12V +/-.
 
While riding, my screen reads 14.3V with auxiliary lights on, brights on, heated seat on, heated grips on.
Well, it reads 14.3 with none of the above on too.
(With engine off it was 14.2, but that was immediately after shut off)
 
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Scott Semone said:
Funny... I had to jump start my buddy's HD before heading off to a ride yesterday; he swears that it's bad for a battery to be left on a trickle charger... Again, I trust the newer trickle chargers have some intelligence behind them these days..
Click to expand...
I had the previous BMW charger (grey little box) for my R1200RT. It destroyed two brand new gel batteries, even though I followed BMW's instructions to the letter. With the first battery the BMW dealer told me to have the charger connected for the whole winter. By spring, the battery was completely dead (tried to refresh it with a different charger to no avail). Got a new battery under warranty. To my surprise, BMW had revised their instructions, so this time the dealer explicitly told me to not have the charger permantly connected during winter. Instead they said to charge the battery every 2-3 weeks and disconnect. So I did this off season and by spring, the second battery wouldn't start the bike unless directly after a charge up. It couldn't hold its charge for more than a couple of hours. BMW wouldn't replace the second battery, even though I had cared for it exactly as they had advised. They stated they would only replace one battery under warranty. So I scrapped the BMW charger, got a Ctek one and managed to salvage the second battery to some extent, but it never came back to a reasonable strength. So I dumped it after a few months and bought a third one which I succesfully charged with the Ctek for many years. I continued with the "every 3 weeks method", never had it permanently connected. Just to be on the safe side.

Sorry for the rant. Point is that I don't trust BMW for taking battery charging seriously, not then not now. Their new charger is supposedly better, but is it really on par with the leading brands? Time will tell perhaps, when there are more long-term testaments. Anyway BMW has no competence in this area - they buy this technology and presumably not from the leading brands.

For convenience though I might buy the new BMW charger if I don't hear bad words about it, and because I don't charge continuously anyway, even with the Ctek. The battery certainly doesn't need a permanent charge, and even if some chargers can be connected continously, it doesn't add any benefit to the battery charging. I have easy enough access to the garage to connect the charger every 3 weeks or so. Another argument for the the BMW charger would be that BMW warns you in the manual from using anything but their own charger. :oops:

Scott Semone said:
I trust that the trickle chargers do as advertised and optimize the proper voltages necessary to maintain my motorcycle battery for at least 5 years
Click to expand...

Before I possibly spend any money on the BMW charger just for the sake of convenience, I need to make sure what the correct voltage is for charging an AGM battery. Yesterday I had a brief phone call from a buddy who claims that AGM batteries should not be charged at the usual 14.4V but instead at 14.7V which the Ctek is capable of in its "snow fling" or "AGM" mode (depending on model). I don't know if this is correct or not, but it is likely what I've been hearing myself. Started googling a bit, but opinions were all over the place and I still have a cold/fever so my brain couldn't handle it for now.

I suspect that the new BMW charger isn't capable of 14.7V. Anyone know? I think the voltage is stated on the display whilst charging?
 
tommymck said:
14V is what comes out of the bike's charging system. The battery tender charges at 12. The battery by itself will never output more than 12V +/-.
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I'm confused, what do you mean? My Ctek charges at 14.4V or 14.7V depending on mode. The new BMW charger only at 14.4V I think (for AGM, correct me if I'm wrong).
 
I'm going to register for a college chemistry class; I'll report back in 3 months or so..

Not sure if motorcycle chargers can bulk charge an AGM; typically, this is a process to optimize the battery after it has fallen below a optimal charge holding percentage. Basically speaking, the process tries to remove any sulfation that accumulates on the lead plates; thus returning the battery back to a healthy charge holding state (however, not at 100%)

I'm going to try and get 5 to 8 yrs out of my AGM battery, with the newer BMW charger; I'll continue charging or maintaining it like I've done with my past GS Adventure. New Bike, New Battery and Charger - only time will tell
 
insomnia said:
I'm confused, what do you mean? My Ctek charges at 14.4V or 14.7V depending on mode. The new BMW charger only at 14.4V I think (for AGM, correct me if I'm wrong).
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The voltage at the output terminals of the BMW charger is 12V (+/- a few tenths) and switches to 14 (plus or minus a few tenths) when the battery is charged and the charger is in maintenance mode. Different chargers operate differently. In any case, your battery, while not hooked to a charger and when the bike is not running will not show more than 12 and a few tenths.
 
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