advice on battery problem/charging

kwackless

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Not been on forum for a while due to working away.. but managed to ride my 2021 bmw r1250 gsa at least once a week bike as never failed to start in the 14 months I've owned the bike from new.. However this morning it did try to turn over but did not seem to have enough juice to turn the starter a full turn! bike as always been on a bmw motoradd trickle charger since brand new and charger is showing fully charge at 14.7 volt.. called bmw breakdown out and they did a test on battery and is fully charge but the battery failed the the test saying battery is unserviceable.. tech said the battery dose not supply the enough amp's to turn the bike over.. well you learn something new everyday! I thought if the battery is fully charged the it should turn the bike over.. anyway the tech fitted a new battery under warranty and it started first time :thumb.

been doing some research on this.. one dealer said it's the bmw battery charger can drain the battery and you should always charge the battery via direct connection to the battery terminals.. what a knob!! he sold me the o.e.m bmw Battery charger saying its just plug and play connects via the din port! another dealer said you must turn ignition on connect charger via din port so charges via the canbus then turn ignition off as this allows the canbus to except the charge.. since having the bike I've always just park with ignition off then connected the bmw charger via the din port always seem to charge the battery full hence never had a flat battery. the bmw tech who replaced the battery said there was some problems with the o.e.m excide batteries being faulty or the battery as been left to discharge from new then recharged at the PDI check over.


do have a datatool tracker and bmw oem alarm fitted from new but in the 14 months I've owned the bike never had a flat battery always started first press on the starter button..

can anyone had this problem or shed any light on this? as not sure if the bmw oem battery charger or the battery was at fault. hoping it was just a bad battery from new as the last thing I need is to be on a ride out stop for fuel or rest and the bike won't start :blast
 
if I was leaving my optimate 4 connected to a bike due to accessories munching electrons then I would want things as simple as possible and like bosnjo, connect direct to the battery via a fly lead. This eliminates a potential problem by removing any electronics and firmware from interfering with the charger's output. All you have is some dumb copper wire. Electrons like copper wire but can get confused when they start messing with silicon and the algorithms that emerge from the minds of BMW's code monkeys.
 
The battery can be fully charged but with reduced capacity.
Problem is, being constantly on a trickle charger will hide the symptoms of a failing battery.
 
Thanks for replies.. I've always used bmw din port to charge via canbus on my previous bmw gs's and never had a flat battery. I did ask the bmw tech who attended and replaced with new battery about this.. he said the bmw charger was charging the battery the way it should do.. and it makes no difference when bmw charger is connected either with ignition on or off.. either connected right away or at a later date.. most likely the battery was left to completely discharge at some point when new which damaged the cells and reduced the battery life.. however I do agree the bmw charger or any other trickle charger will masked the problems of a bad battery until the battery just gives up completely.. the new battery is under full warranty if it happens again then will consider using a optimate trickle charger direct from battery terminals. However must congratulate bmw assistant.. when I called bmw assistant they arrived at my home with-in 30 mins then rang round dealers to locate new battery which was in stock then the tech drove 90 miles round trip to main dealer to collect battery returned 2 hours later to fit battery.. got to give credit where due.. excellent service just goes to prove.. you only get what you pay for.
 
Dead batteries do appear to be reasonably common on BMW bikes. My bike (21) was stone dead in the showroom when I went to look at it and it was only 14 months old. It now has a Yuasa rather than the original and I have it connected to my Optimate 4 Canbus which appears to be doing its job.
It’s not a “constant trickle charge” it’s a monitor that only comes on if it detects a reduction in the charge state.
 
On my 20 months old GS I used trickle charger (direct to the battery) only twice, when I was 1 month away for work. Then I stopped using it. During my last trip I was away for 20 days and bike started fine after that.
 
Trickle charger

Aberdeenangus.. Suppose not.. but something I've always done on all my bikes.. never had a problem with a flat battery before.. reason why bikes always on chargers is always had at least 2 bikes at any one time.. also got a 21 plate R nine t which I love to bits.. so tend to use 4 wheels pending weather..... hence bikes can go weeks without turning a wheel.. hence trickle chargers.. that's the British weather for ya!! plus I've gone a bit soft in my older years.. lol....
 
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I never leave a bike on a trickle charger, I don't trust them to remain connected long-term regardless of their sales bumph.

I give my GSA an occasional recharge with my CTEK MultiXS charger via an accessory port wired across the battery as I know its Datatool tracker will deplete the battery over time if the bike is not ridden.

Each cell of a lead acid battery is 2.2 to 2.3 VDC at full charge, so multiplied by six cells is typically an open-circuit voltage of 13.2 to 13.7 VDC. If your battery shows 14.7 VDC open-circuit without being connected to a charging source, something is wrong.

Battery terminal voltage readings are only a "rule-of-thumb" to the state of charge, to be accurate you need either a hydrometer reading (difficult with a sealed cell battery) or a drop-tester to put it under loaded conditions and measure it for amps supplied.
 
Trickle charger

Aberdeenangus.. Suppose not.. but something I've always done on all my bikes.. never had a problem with a flat battery before.. reason why bikes always on chargers is always had at least 2 bikes at any one time.. also got a 21 plate R nine t which I love to bits.. so tend to use 4 wheels pending weather..... hence bikes can go weeks without turning a wheel.. hence trickle chargers.. that's the British weather for ya!! plus I've gone a bit soft in my older years.. lol....
 
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Bike only reads 14.7 volt when idling when started which I assume is the alternator providing the higher voltage.. which tech said is correct.. when connected to bmw charger when ignition is off it reads battery fully charge and reads 13.7 volt.. which I assume is normal.. as the tech told me all is fine with the battery and charging system.. just bad luck I got a bad battery from new..
 
Yes the 14.7V is the regulated output from the alternator, the extra voltage needed to provide electron flow into the battery at its lower voltage level.

Batteries suffer from a condition known as plate-sulphation where lead sulphate builds up on the battery plates over age, leading to self-discharge within the battery itself which drags down its capacity and ruins its ability to accept charge due to a high internal resistance. Once the sulphation process starts it can become quite rapid so the battery that seemed fine recently can suddenly call it a day.

Some smart chargers can shock a battery with a quick blast of forced charge to break down the lead sulphate, but this often degrades an already depleted battery.

For the cost of a new battery IMO, its never worth the hassle of being stranded. They always seem to fail when you are far from home or in a rush. Once they start getting tired just change them.
 
I've used an Optimate 4 on all 3 of my GS' connected direct via the supplied flying lead as it also gets used to power my heated vest and airman pump. My 1250 went through far more top up cycles than the 1200s I had before it (based on how many times I randomly saw the yellow charging cycle in action) Now I've disconnected the datatool stealth tracker after cancelling my subscription normal business has been resumed and the optimate is invariably either solid green or flashing green when doing it's monitoring cycle when I visit where it's stored which is probably about once a day. I've not had any problems starting my bike at any stage after leaving my optimate permanently connected while it's not in use
 
Pukmeister.. never had problems before with trickle chargers being connected continuously either by canbus or battery terminals.. however I agree it's not required all the time to keep on trickle chargers. Also have my R nine t on optimate 4 charger via battery terminals. also have a spare optimate 4 TM lead if any more problems with bmw oem charger via canbus if it caused the charging to fail.. will fit the spare optimate lead to gsa terminals and use the optimate 4 on both bikes on a week on and week off basis.. either way Surrey.. it's makes sense to keep batteries on tenders to keep a good healthy state.
 
got a point there with cancellling trackers.. I'm also not going to renew the tracker on my r1250 and r nine t when next due.. as the trackers cost so much more than the discount allowed on insurance.. also I only got 12 pound discount on insurance for having datatool tracker fitted to my r1250 gsa also with me having a multi bike policy data tracker will only allow the discount on the one bike.. what a rip off.. doing the insurance a favor and they shaft you.. so wil not be renewing trackers when due..
 
Littleade.. so when cancelling trackers dose that not disconnect from elec system on bike? So even when cancelled the trackers still draw power? as I did not fit the trackers so not sure how they are disconnected From the elec system
 
update..

not sure if this info helps.. but completely cheesed off with paying for 2 trackers on my r1250 gsa and r nine t and getting a just a £12.00 pound discount on my multi bike insurance.. with the tracker per bike cost per year £120.00 to renew thinking why bother if the trackers drain batteries.. so called datatool tracker today and put the question of trackers draining batteries.. he said datatool I've no control over discounts on insurance "which is a fair point" but as assured me the datatool tracker will not draw enough power to drain a battery unless left weeks weeks without use and battery could go flat with or with-out a tracker fitted.. "which is also a fair point" and if bike is left on a battery trickle charger the tracker will not drain the battery.. in fact a small voltage draw will prevent the bmw trickle charger going into sleep mode and prevent the canbus shutting down.. do you agree this makes sense? or is the tatatool tech talking bollocks? at the moment.. my bmw r1250 gsa is on a bmw trickle charger and states fully charge at 100% and reads on charger charger 100% I=O.0A U=13.8V I'm not pretending I know this reading means but assume it means all well. the datatool tech also said if you cancel the datatool subcription and let them know you want to cancel the tracker they can shut the tracker down which dose not allow any elec draw so no need to have tracker removed or disconnected from elec system.. suppose this make sense as the next owner may want to reinstate the tracker..
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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