bmw genuine battery tender advice please!

[kwackless]

This is my 4 th bmw gsa and never had a flat battery until now.. last week at to call bmw breakdown service as my 2021 r1250 gsa refused to start due the flat battery.. the tech said the battery is un-serviceable and fitted new battery under warranty.. always kept my r 1250 gsa on a bmw genuine battery tender.. however the bmw tech said.. the genuine bmw battery tender cuts it self off then the bike will drain the battery.. what!! he reckons some bikes did this and a software update will prevent it from happening again.. I asked him about the so called "this is what you should do connect the bmw tender" meaning you turn ignition on connect tender via din port the turn ignition off.. he said that's not correct just plug in and the tender will mantain the battery as is fully auto..

My gsa is due for the shaft drive prevention drill hole with the rubber bung recall.. and asked the tech about this software update to prevent the canbus shutting off power to the din port causing the bikes to drain the battery! he said never heard of any soft ware update to prevent this from happening.. to be honest not sure if the bike did shut off the dinport causing the battery tender to turn off..

Reckon it's best to ask the guys who own and ride these bikes when using the genuine bmw tender if theirs shut down and drain battery.. it's possible of course I was just unlucky and got a "not so good battery from new" as the bmw tender always seems to be on.. it charges the battery to 100% full then reverts to power saving mode.. it's states battery full yellow light led on and states "power saving mode" not sure if this states now maintaining battery and will add charge if required or it means the canbus as shut off the din port.... any advice on how the bmw genuine tender works and what the yellow led and power saving mode means.. I.E all well or tender as shut down would be appreciated.. as now thinking of binning the bmw tender and using a optimate 4 tender direct to the battery terminals... I understand I could just use the croc clips and the bmw tender direct to battery but the reason I bought the bmw tender is I could just plug into the din port and not keep removing the side panel to gain excess to the battery terminals.. ok removing the side panel is not a big job but the bmw tender is suppose to be designed to plug into the din port and maintain the battery and not shut down when the battery is full and then to drain the battery.. also just to confirm I do not have any other elec accessories connected to my gsa except the o.e.m nav 6..

 

[DJ123]

No battery charger continuously chargers. They all allow the battery to fluctuate in voltage and they will top it back up if necessary when it drops to a particular level.

If you're going aftermarket Ctek are a decent brand as are Noco. Both have the option for a small connection eyelet to easily be accessible & hidden away when not in use - they also have the option for one which shows battery health status too.

 

[kwackless]

bmw tender

No battery charger continuously chargers. They all allow the battery to fluctuate in voltage and they will top it back up if necessary when it drops to a particular level.

If you're going aftermarket Ctek are a decent brand as are Noco. Both have the option for a small connection eyelet to easily be accessible & hidden away when not in use - they also have the option for one which shows battery health status too.

DJ123.. thanks for the reply.. but I already know that! I also have a r nine t that's on a optimate 4 tender.. which charges the battery and can tell when it's in maintenance mode as the green led flashers for 30 mins then either supplies small charge with a yellow led or the green led turns solid green.. easy!! just need to know when the bmw genuine tender via the din port when it's states battery full and in power saving mode with the solid yellow led on dose it mean the tender is maintaining the battery or as the canbus shut the din port off? to be honest I think the bmw tender is working correctly.. and I just got a drained down battery from new hence it only lasted 12 months!! but with the bmw breakdown tech saying there is a software update to prevent the canbus shutting the dinport down and a bmw dealer tech saying he never heard of a software update to prevent the canbus shutting the dinport down.. if someone could explain what the 100% full and stating power saving mode and yellow led on means on the bmw tender.. I.E maintaining or not! then I will know if the bmw tender is maintaining or shutting down.

 

[Combine man]

Have used the BMW charger for a couple of years,just plug it in and CAN connects after a moment, the charger goes through its check/ charge cycle,and then if all ok reverts to power saving mode,it will maintain contact via CAN whilst connected and correct any changes in the battery whilst it is connected. The advantage of the CAN is that any consumers that are drawing current shouldn't be able to drain the battery with the charger connected
There is no magic with CAN Bus systems they are very reliable and stable carriers for charging with devices like you are using. The life expectancy of modern batteries can vary dramatically on all machines,so perhaps just bad luck.
Have no knowledge on BMW software updates,in my market,agricultural machinery,people reach for a software update too easily,if its a mandatory update that is vital to install the Dealer network would all be informed,and paid for the installation,if there are later versions of Software avaliable,but not mandatory, discretion should be used,also the if its running don't fix it mantra.
You are better using the socket than connecting direct if the facility is avaliable, modules that CAN serves are prone to damage from unstable charging especially jump starting.
We can no longer jump start our machines,diesel engines over 500hp, for fear of spikes in voltage damaging modules. Another good reason to do all you can to avoid flat batteries.
Most engines need to crank at a certain speed before ignition is allowed to commence by the various systems, so slow cranking is bad.
Modern electronics are all high consumers on power,the TFT screen for example,and as battery size decreases and demand increases on the battery their condition and correct monitoring is vital.
You can find an ops book for the BMW charger on the Internet,explains lights etc,sorry to go on,but it is a wide and varied subject,what ever machine it applies to.

 

[Engineer]

The latest BMW charger works just fine on my 2021 1250GS TE

 

[kwackless]

bmw tender

Combine man/engineer.. Thanks for the conformation on how the bmw tender operates.. at least I know when in power saving mode.. the canbus as not shut down the bmw charger and is still maintaining the battery. have always had the bmw tender via canbus dinport connected since I got my gsa from new.. so most likely a battery fault from new.. new battery fitted under warranty now and bmw charger seems to be maintaining the battery.. the charger is in power saving mode now so seems to be maintaining the battery.

 

[kwackless]

My bike dose have a software update available so it's booked in to have it updated.. so hopefully it will prevent the canbus from shutting the din port down which the discharges the battery.. took my 2021 gsa in for the shaftdrive recall where they drill a hole in the shaftdrive and fit a valve to let any water if trapped and prevent any condensation that may build up. The tech said there was a problem with the canbus shutting down the dinport which drains the battery.. and there is a software update that prevent this from happening..