This will be the first in a series of posts showing real world examples of troubleshooting lithium battery issues. Or, more accurately, troubleshooting electrical issues when a lithium battery is being used.
Over the years, Ive found that there is a great deal of mystery surrounding electrical systems on motorcycles, and as a result, parts are often replaced until the problem goes away. This is neither efficient, nor effective.
This post will be a direct copy/paste of a email with a guy this morning. He wasnt using one of our batteries, but asked for help anyway. I answer these as fully as I can.
I saw the beginnings of a blog post comparing lithium batteries and wanted to see if you ever got around to finishing it?
I've been having really odd issues with by 07 BMW G650X, thought it was an aging battery, bought a cheap B*****y T****r Lithim and it caused all kinds of issues.
Seemed like the continuous discharge was super low or the pulse current was low. Bike would literally cut power under too much throttle. Solved when going back to the original, old battery.
In terms of continuous discharge current and 30-second pulse, how do your batteries compare to a totally average sealed acid battery or an Odyssey?
Sorry for the late response. Ive never finished the blog post comparing batteries for a few reasons. Without delving into them, it would have made a bunch of retailers angry, and that is just never a good idea.
Sorry to hear that you are having issues with your lithium battery. Im curious about what could have been causing the issues you describe, if the battery was the only thing you changed. That would indeed be very…odd.
Cutting power under throttle (from an electrical perspective) indicates that the coil supply + or the injector supply + wires were not connected/undersized/etc. Ive seen this happen on bikes with big piggyback systems like MOTEC and MSD- but never with a stock ECU. This could also be fuel related- pinched line, etc- but Ill just stick with battery and charging system here.
Im also curious to know if you performed any measurements on the battery and/or bike during this time.
What was the battery voltage while bike was off? How about running? Was the lithium battery charged? Was the lead acid battery charged? Lots of details to think about to do a proper analysis. If you need help looking at this in the future, give me a call.
In discharge comparison to an SLA or AGM battery (Yuasa, Odyssey, etc) our batteries are relatively comparable, but those figures are not really applicable, in my opinion. Our P3’s 30 second pulse would have no trouble with 50 amps- but there is no way that your bike would ever require that.
More important than battery specs however, is understanding what your bike would actually use.
The stock charging system on your bike is rated 280 watts @ 14v, or 20amp. Keep in mind that figure is MAX output, and will likely be much less most of the time. Id guess that there is maybe 25-28 watts of overhead for charging the battery in that figure. ( I don’t have access to this bike so these are guesses)
So, if your bike is running- and the charging system is working- there should be plenty of power coming from the charging system to power all of the stock equipment. If that isn’t the case, either you have added a ton of aftermarket gear, like lights, GPS, etc, etc, which has severely overtaxed your charging system and battery…or your charging system is not working.
Unfortunately, this is impossible to know without knowing the measurements.
For reference, a working charging system on a modern motorcycle should show voltage above 14v while running at 2000rpm.
A lithium battery in good health should generally be around 13.6, and never lower than 13.2.
Hope this is helpful.
I have not heard back from Micah about this.