Originally Posted by Antigravity
..........Through the last year I have tested and re-tested so much that it has changed my outlook on batteries...
I no longer look at Amp Hours as that much of a factor at all... Power is absolutely the king and most important factor bar anything...Starting your bike is the number one thing that must happen especially if your in the middle of nowhere....Sufficient amp hours will follow the Power if you get the proper size battery... My argument for this is just from so much testing and experiance and understanding the principals ignition systems of vehicles..........
I could not agree with you more if you were holding a gun to my head.
A little about my experience, not to toot my own horn, I have plenty of bad traits, ask any of my x girlfriends for corroboration, but to point out areas of experience.
1 year with independent volvo dealer.
4 years as a licensed industrial electrician. For the last 2 years, amongst other things I was responsible for $600,000 worth of backup power batteries for an industrial process that had to be shut down gracefully and if not, we were to place a call to the local FD so they could drive quickly in the opposite direction
2 years as assistant instructor for the industrial electrician feeder school.
3 years as a tech at a factory volvo dealer rising to lead diagnostic tech in the first year past techs with 30 times my experience.
4 years with Volvo NA corporate as a technical assistant (read FSE but paid less due to lack of degrees). Front line on many electronic issues and a lot of testifying in law suits over things like "thermal events". Ford acquires Volvo, a few days after rolling an XC while tracking down a stability control firmware bug, i'm reprimanded for not holding the handrail while traversing a half flight of stairs at HQ, my departure was sudden and memorable
7 years back to inde Volvo dealer as service manager.
2 years at large BMW motorcycle dealership after move across country, most of which was as shop foreman.
POWER IS KING!
I would have to say 9 out of 10 bikes that arrived on a flatbed could be started simply by hooking up an automotive jumper and cranking them over faster.
The usual culprits were stuck fuel injectors, stuck fuel pumps, shitty old gas, and sensors that were broken leading to sub-optimal fuel mixtures for easy starting.
Sometimes an injector would have to be tapped with a screwdriver to unstick it. Sometimes a pump would have to be jogged back and fourth to free it, but more startup voltage helped with everything.
In an adventure bike, my first step to reduce being stuck in BFE would be to install a battery with serious cranking power.
That said, and especially specific to modern BMW's, I'm not yet sold on lithium chemistry for adventuring.
One very common event with almost all modern BMW's is for the ZFE (basic module by industry terms) to glitch randomly a couple times a year, not shut down and draw anywhere from 0.2 amps to 2.3 amps till the battery is dead.
There is no outward sign of this occurrence so customers usually have no idea why their bike started fine the day before and was too dead to light up instruments the next day.
I know about this because I was in the club. It is an issue I have watched and verified live and which all levels of BMW corporate is aware of but likely not sharing with Excide/Yuasa, their battery vendor.
So dead flat batteries happen. They happen because someone wires something to the bike and forgets to turn it off. It happens because people leave the key on, and it happens because modern BMW's occasionally glitch and do it all by themselves.
Stated over and over in this thread and on your web site is that running any battery too low will damage it.
This is technically true but there are differences of degree.
I will happily run either my personally owned ETX14 Deka AGM or PC535 Odyssey batteries dead flat, then bolt a piece of copper across the terminals and leave it for 48 hours. At the end of this the resting terminal voltage is going to be mili-volts. I will then break out my solar charger which is the biggest woos of a charger in the world and after a few hours in the sun, the bike will start. After that, hook it to a nice push charger, crank the voltage well into the gassing range and 4 hours later the batteries will still meet published CCA and AH and from past experience last years.
Is this hard on a lead acid chemistry battery? Yes
will all brand AGM's do this? NO, Yuasa / Excide sure won't, But Deka, Odyssey, and some others will.
In my experience all chemistry lithium batteries are instantly bricked when you hit a resting voltage of mili-volts.
The next thing that is important to me while adventuring is how the battery takes over voltage. R/R's break. I have seen it in the shop many times. Sometimes the customer is even unaware and comes in cause he's blown his headlight bulb 3 times in 3 days. We replace the bulb, fire up the bike, check the charging voltage and see 17.5 volts and rising.
Lead acid batteries hate this and will eventually dry out from it. They will even go into thermal runaway if it happens continuously for hours in a row. Thermal runaway in a lead acid battery is characterized by bulged and even cracked battery cases, but thats it that I have ever seen.
Conversely I have seen lithium iron phosphate auto batteries have "thermal events" from these same levels of over voltage. Did they explode? NO. But they made a lot more flames then I would want under my seat or fuel tank.
For the two reasons above, I am sold on lithium batteries for commuting and race / sport use, but would want to see a protection circuit for adventuring use.
I don't need to see a full on BMS, but some sort of protection from under voltage would be desirable and at the very least, a piezo that screams when voltage or temperature gets extreme. Also the under voltage protection should not brick the battery. A nice diode so I can put current in would be desired.
I love batteries, always have and always will.
My current main ride is an Aprilia Caponord which is insane in it's CCA requirements versus it's battery box size. On a -8F day I measured an average 236 amp draw for 6 seconds before the bike started. The only reason it did start was my Deka ETX14 managed to outperform it's specs and maintain a terminal voltage of 9.3 volts which was just enough for the ECU to remain conscious.
I can find no lead / acid battery that will reliably start these bikes when it is super cold AND fit in the ytx14 sized battery box, but I have a lot of reservations about Lithium sans protection circuits and also plenty of reservations about the protection circuit durability and how reliably it will prevent bad things.
So, with all that stated:
Antigravity, Thermal events? If the battery sees 22 amps unregulated for a few hours, with your battery are we talking some smoke and vapors? Or time to call my insurance company?
Under-voltage protection circuits. How far away are we from having one? Need a Beta tester?
I would like to become a fan of lithium SLI batteries, but I need my concerns rectified first.
And _CY_ Nice thread and I applaud you and everyone else for venturing into the bleeding edge so that it can become cutting edge. Since you seem to like specifying equipment used for testing and picturing it, I will specify mine :p
Fluke 289 used for minimum voltage in "peak" mode, so 250 micro second response time. Calibrated 3 months ago.
Fluke 867B and deltronic 400 amp precision current shunt. The 867B hasn't been calibrated in ages but I check it against the 289 regularly and it is still spot on. The current shunt has never been re-calibrated but shunts don't go out of calibration unless they oxidize, melt, or warp, none of which has happened so it is at the least an order of magnitude more accurate then any inductive probe.
Fluke 196 scope meter to watch the voltage and current draw graphically just because I like to see things.
I think I have you beat on test equipment lol