Just installed a lithium iron phosphate (LiFePO4) battery

[Star-Lord]

This does not sound right.... a lithium should sit happily at the normal 14.4v..... all most sounds like it's bms is open circuiting for some reason and the bikes electrical system can then not regulating properly.... make sure the terminals are tight etc.... no loose earth. Generally the battery will take all the current your bike can give it and eventually the bike will settle at max of 14.4v and current would tail off.... no way would the bike regulate to 18v unless it can't see a functioning battery (cells).

In broad terms, lithium act like lead acid.... basically "4 series cells" that are happy in the 13.2 to 14.6 or so voltage range..... So for 18v to be seen the bike's electrical system isn't seeing a functioning battery at that time. So reasons for this could be: bad connection, faulty battery, bms activating to protect cells (over heat, to cold, over current, over voltage).

Has anyone poked around on the GS-911 in order to see if battery type or chemistry is a variable parameter..?

Maybe the HEX site has something listed..?

 

[Keehn]

Has anyone poked around on the GS-911 in order to see if battery type or chemistry is a variable parameter..?

Maybe the HEX site has something listed..?

I haven't. However, if the Lithium battery has an onboard BMS (like it should), and the seller advertises it as a "drop-in" AGM replacement, then it shouldn't matter what type of charger you use, so long as it doesn't exceed the max charge voltage of the battery.

I mess around with lithium chemistry batteries all the time, and I've had zero issues charging PROPERLY rated 12v LiIon and LiFePO4 batteries on dusty old lead acid chargers (I have an old Cushman electric golf cart with six LiIon batteries using a basic lead-acid charger). The only caution I would give is to NOT use the fancy multi-stage lead-acid chargers (the ones that can desulfinate), as they exceed max allowed volts during the desulfination process, and WILL destroy lithium chemistry batteries in short order!

For any skeptics out there, grab a simple multimeter and observe the output voltage of a Lithium-compliant charger, versus a simple 12v lead-acid charger; they should be virtually the same output. Just think of these simple chargers as water filling a bucket (the battery); once the bucket is full, it accepts no more, and both sides are in equilibrium. For individual cell management, that's what the BMS is for, plus the BMS bleeds off any excess voltage it sees (which shouldn't be much on a properly-sized charger).

But, don't simply take my word for it. I'd encourage anyone who wants to do this to conduct their own research and decide if they are comfortable moving onto lithium. I'm just a guy on the internet who has .02 cents on the matter.

Mike

 

[laennecr]

I haven't put a Lithium battery in my R18 yet however I've put them in 2 other BMWs - R9T and S1000rr and did not have to code the battery type. I don't believe the bike knows the difference just that the charge is correct and the charging system charges the battery. 18+ volts is an error or a serious problem.

 

[DonC]

I’ve used Shorai LiFePo batteries in 4 different bikes now, just replaced the glass mat stock one in my R18 with a Shorai. Never a problem, not one, zero, lasts much much longer, doesn’t self discharge when the bike sits, lighter, stronger, just better in every way. A good charger with a LiFePo setting that works with BMW canbus and can be plugged right into a power socket on the bike is small enough to take with you if not being near a charger is an issue for you. Lithium ion batteries have a problem of overheating and bursting into flames, not LiFePo. The only drawback is initial purchase cost, but if they outlast 3 glass mat batteries (they will) then it’ll more than pay for itself in the long run.

 

[Noelpolar]

As an aside.... I have had a 90ah lifepo4 under the bonnet in a hot enviroment (Landcruiser 200 TD) for a bit over 6 years now. I load test it most years to check what capacity remains. I need to pull 90 amps from it for 15 to 20 minutes at a time (coffee machine). Still performing ok.... and it is just 4 cells with no internal BMS (Winston 90ah).

After 6 years it still performs better then a new 100ah AGM at high discharge rates (5 hr rate or more)..... but is deteriorating at about 2x it's normal rate for a normal temp enviroment.

The only issue I have come across in motor vehicle applications is with low vehicle voltages when vehicle charging systems are "smart" or temp compensated and drop voltage below 13.4v or so.

 

[r12mike]

I installed a Li Iron battery because the R18 seemed to have a weak crank sometimes, thus I assumed the battery was low, or at least losing its peak performance. When I took a ride with the Li Iron battery my charging voltage shown on the digital display was 18-19 volts. Seemed much too high from what I am accustomed to seeing. I visited my local BMW dealership and asked about it but did not receive any reasonable answer. They simply do not know why this is. I called BMW USA and got even less satisfactory response. I uninstalled the Li Iron battery and installed a AGM battery (which is what BMW literature recommends for this bike) and upon start up and riding the voltage levels are back to 13-5 - 14.2 which is what I am used to seeing and can live with. My R18 is out of warranty so I really do not want to take chances on burning out a voltage regulator or anything else. As far as I am concerned it is AGM forever for this bike. Frankly I am a little disappointed as I was pretty excited about trying out this new technology.

 

[laennecr]

I installed a Li Iron battery because the R18 seemed to have a weak crank sometimes, thus I assumed the battery was low, or at least losing its peak performance. When I took a ride with the Li Iron battery my charging voltage shown on the digital display was 18-19 volts. Seemed much too high from what I am accustomed to seeing. I visited my local BMW dealership and asked about it but did not receive any reasonable answer. They simply do not know why this is. I called BMW USA and got even less satisfactory response. I uninstalled the Li Iron battery and installed a AGM battery (which is what BMW literature recommends for this bike) and upon start up and riding the voltage levels are back to 13-5 - 14.2 which is what I am used to seeing and can live with. My R18 is out of warranty so I really do not want to take chances on burning out a voltage regulator or anything else. As far as I am concerned it is AGM forever for this bike. Frankly I am a little disappointed as I was pretty excited about trying out this new technology.

what brand of LiFe did you install?

 

[MilwDave]

Iaennecr: The battery I posted in the link above is the same size as the original except maybe <1/3" more narrow. I used a very thin piece of closed foam to keep it tight. It fits perfectly which is important as a motorcycle battery must not shift! The rubber strip that secures the front of the original battery is still very effective. Yes the battery is less than half the weight of the original. Inserts very easy..primarily because it is light weight. Best part of using a Li battery is you do not need to keep a charger on the battery if you ride your bike only every couple of weeks or longer. The Li battery holds its charge much longer than an AGM and your bike can quickly recharge it in a fraction of the time it takes to recharge an AGM. It will outlast an AGM. I have the anti-theft disabled so that long-term secure storage makes the drain negligible and the remote key is kept stored at a distance. Note that if you do use a charger...it MUST be Lithium enabled. I cannot understand why someone would not replace a lead acid or AGM motorcycle battery with the latest Lithium generation with LiFePO4 and BMS.

I’m 0 for 3 using lithium batteries from both Shorai and NOCO. All were replaced under warranty snd I sold the replacements.
I may be unlucky but the failure rate on lithium batteries is unacceptable.

 

[DonC]

what brand of LiFe did you install?

I have always used Shorai, and had no problems.