Ultrabatt lithium batteries

[FastBikeGear]

exactly how many times?????

I think I understand your question.

If you are talking about how many discharge charge cycles you can get from a LiFePo4 battery the answer will depend on similar factors that effect a lead acid battery life:

1. The percentage of discharge before recharge. Smaller cycles give your battery a longer life. The charge discharge cycyles on a motorcycle are typically very small and a motor cycle battery will be typically fully rehcarded within 5 minutes of starting your bike.
2. The rate of disharge for each cycle (typically the only thing that will significantly discharge a motorcyle lithium battery is cranking amps. High discharge rates will decresase the life of your battery. LiFePO4 otorcycle batteries are designed for high discharge rates.
3. The rate of charge (Lithiums like to be charged hard and fast relative to lead acid batteries i.e greater than 1 amp and less than 10 amps (which is exactly what a motorcycle charging circuit typically does)
4. Whether or not your battery is charged back up on every occasion with a BMS. (This is why batteries with internal Battery Management Systems prove much more reliable and have much longer service lifes. (It;'s also why we are beginning to see inbuilt BMS systems in more expensive lead acid batteries used in, Fork lifts, Solar storage and back up power systems. BMS systems save money by greatly extending the life of batteries.
5. Whether your battery has regularly been under or over discharged.

Lithium battery manufactures typically talk about 400,000 charge cycles.

"Hi David, I worked in a LiFePO4 battery manufacturer in China. The fast charge & discharge performance of LiFePO4 are usually limited by PCM. And 400,000 cycles@80% DOD (Depth of Discharge) is theoretical.

Daniel Sidor
Technical Manager at FESMC Energy Services"

A lithium motorcycle battery [with an inbuilt BMS] is designed to have a service life of 10 years with a very low failure rate. Do the designers know what they are doing? Well you only need to compare the MTBF (Mean Time Between Failure rates) and a very clear picture is beginning to form - the life fo a lead acid battery seems to be a bit of a risky lottery in comparison to purchasing a lithium battery (with an inbuilt BMS).

Unfortunately the failure rate for LiFeP04 motorcycle batteries without an inbuilt BMS systems appears to be nowhere near as good. Unfortunately reliable fault statistics for LiFePO4 batteries without BMS systems are not available to us.

But here are some statistics we do have. (Source Kiwibiker survey, FBG records as of 16/09/2013)

The Kiwibiker survey by the nature of the type of people who respond is not ideal for the following reasons. 1. It has been completed by motorcycle enthusiasts who probably care for their battery better than motorcyclists who are not so enthusiastic, 2. It has been completed by people who are particularly interested in the results. 3. There is more chance of someone who has had a particularly good or bad experience completing the survey. 4. There is a relatively small sample group. 5. The group includes customers with both original fitment and aftermarket lead acid batteries and there is anecdotal evidence to suggest that original fitment batteries are higher quality and last longer than cheaper after market lead acid batteries. So as a sample group it is not ideal.

The FBG statistics have a much larger sample group but is again not ideal. The group represents a cross section of all people who have purchased batteries but again this is a group who has taken a stronger than normal interest in their batteries. FBG statistics do not include batteries which have had their protective short circuit fuses replaced - we had two customers blow the fuses in 2012 and none so far in 2013). Protective short circuit fuses used to only be factory replaceable - they are now dealer replaceable).

End of 1st year
Lead Acid - 7.69% failure rate
Lithium with inbuilt BMS less than 1%

End of 2nd year
Lead Acid - 10.25% !
Lithium with inbuilt BMS less that 1%

End of 3rd year
Lead Acid - 25.63% !!
Lithium with inbuilt BMS (no statistics as yet)

End of 4th year
Lead Acid - 33.32% !!
Lithium with inbuilt BMS (no statistics as yet)

End of 5th year
Lead Acid - 48.7% !!
Lithium with inbuilt BMS (no statistics as yet)

I am picking that total accumulated lithium battery failures will remain very low (in the single digits) up to the 5 year market. After 5 years I am picking we will see a slight increase up to about 8 years and then a higher failure rate form 8 years onwards. But who knows?

[avgas]

400,000 cycles@80% DOD (Depth of Discharge) is theoretical.

Have you ever run your battery 80% flat?

[FastBikeGear]

Have you ever run your battery 80% flat?

Yes I think so. The reason I say 'I think so' is that the Ultrabatt UB200, UB400 and UB600 series batteries all have anti-bricking technology in them so they cut off in the same way as your Lithium powered drill does before they go fully flat. We have never been advised of what percentage of discharge they cut off at. But I am guessing it is around the 80% DOD point.

Although they are sold as starting batteries I have used the Ultrabatts for a variety of tasks including to power Stonk Lights in my workshop and as a portable power supply for my iPad when travelling. Today I am currently using one as a bench top power supply to heat soak test an OVP (Over Voltage Protection) circuit I am designing to protect motorcycle ECU's ABS systems etc in the event that a RR on a bike goes rogue.

I have a customer who completely flattened a UB400 to the point where the protection circuitry cut in trying to start a Motor Guzzi (that was never going to start because of faulty ignition coil wiring - which I subsequently fixed for him).

We also have customers who have used them as total loss batteries on race bikes, so I am guessing that on occasion that one or more of these guys has also flattened the battery to the point where they have cut off.

"Very good product! I have an RVF400 race bike running total loss ignition and with the lead acid batteries I would change to a fresh charged battery mid day. With the UB400 I can get a full day of racing and only drop 0.2V, Mike Sullivan"


But I am curious as to why you ask?

Typically in usage as a motorcycle battery (in non total loss systems) I doubt whether most customers ever flatten them more than 10%.

I estimate that about 90% of Ultrabatts sold in New Zealand have been fitted to road bikes just to save money and get rid of hassles.

[jellywrestler]

[QUOTE=FastBikeGear;1130612597 they also charge up on your bike many times faster than a lead acid battery.

[/QUOTE]

exactly how many times?????

I think I understand your question.

dont think you do your answer hasn't backed up your statement, you said they also charge up many times faster, which says to me that they'll charge many more batteries in the same time span as lead acid batteries, so how many is the case?

[Drew]

Fuck me, I'm confused Spyda.

Are you asking how long it takes to charge an Ultrabatt from 80%ish discharge, to fully charged in normal motorcycle running conditions?

[FastBikeGear]

exactly how many times?????

Sorry now I understand your question.

The Ultrabatt UB400 and UB600 series batteries have a maximum recommended charging rate of 20A.

Yes you can charge a lead acid battery at this rate for short periods (although it's less than ideal for it's life span especially on a small motorcycle battery!) ....but just because you are chucking amps at the battery at a high rate doesn't mean to say it is actually charging at a high rate.

Because lithium batteries have very low internal resistance, charging at comparitively high amps does not cause as much heat build up (excessive heatt build up helps shorten the life of all typed of batteries).

The on board BMS in the Ultrabatt Lithium batteries assists in enabling a very fast charge rate while still achieving a perfect balanced cell charge. If you try these kinds of charge rates in a lithium battery without a BMS your results may vary.

Typically within 5 miuntes of using your starter to start your bike you will have a fully charged battery. So you could start with charged battery, start your bike do 3 or 4 laps around Hampton Downs, stop your bike, start your bike and repeat for months on end.

You can fully charge a flat Ultrabatt battery in about 20-30 minutes on a motorbike with a 350 watt or greater alternator.

What does this mean, well if you completely flatten the battery. Then push start your bike and ride it for 20 -30 minutes it will be fully charged to the point where you couldn't charge it any further.

The new series of multiMIGHTY batteries have a recommended maximum sustained charging rate of 10 amps for a single 120 PCA PowerBlade. So they also have a very fast charge rate. I haven't confirmed yet but I would imagine the maximum sustained charging rate for 3 blades (the equivalent of a UB600) would then be close to 30A.

Graeme I hope I have answered your question?

[avgas]

But I am curious as to why you ask?

Bricking mainly. But there was lots of whoo-ha a few years back about Lithium suppliers claiming 1000's of cycles @ X % DOD. Outside of that the statistics were far worse. The workaround was to build cut-off circuits so that the Lithium batts never exceeded DOD. The subsequent off-shoot of that was the fancy tech caused thermal run-away and in Sony's case.....fire.
Usually the electronics these days (its been 5 years) is pretty good. But I have still seen the od' either electronic failure (making 100% DOD - and causing single digit cycles rather than 1000's) or DOD by-pass failure (boom). So I am very suspicious when someone tells me to trust the black box without telling me what it cuts off at.......then telling me figures of superior quality with figures.

e.g. We have 100% successfully safe landing with landing gear.
How often does the landing gear fail?
Dunno - at least 90% of the time.
Do you have unsafe landing when the landing gear fails?
Never thought of that.

A million cycles @ 80% DOD is the same as 1 cycle @ 100% DOD if they BMS doesn't cut out before 80% DOD. In Sony's case they never exceeded 90% DOD - but they had some cool fires when it got close (solution was to shut down equipment @ 80% DOD).

[Drew]

Graham I hope I have answered your question?

It's Graeme, I think. In true KB fashion, since you got that one detail wrong, the entirety of the post is wrong.

Sorry, thanks for playing, you are the weakest link, goodby.

[FastBikeGear]

Bricking mainly. But there was lots of whoo-ha a few years back about Lithium suppliers claiming 1000's of cycles @ X % DOD. Outside of that the statistics were far worse. The workaround was to build cut-off circuits so that the Lithium batts never exceeded DOD. The subsequent off-shoot of that was the fancy tech caused thermal run-away and in Sony's case.....fire.

Like you I have a degree of scepticism of MTBF claims, that are calculated or manufacturer only claims. Hence my reason for being more interested in actual field results.

the electronics these days (its been 5 years) is pretty good. But I have still seen the od' either electronic failure (making 100% DOD - and causing single digit cycles rather than 1000's) or DOD by-pass failure (boom). So I am very suspicious when someone tells me to trust the black box without telling me what it cuts off at.......then telling me figures of superior quality with figures.

I think that even if you were given the circuit diagram of the BMS you still wouldn't be able to calculate the MTBF. I think what counts for customer confidence is what customers really experience. For many people only seeing is believing....I think I fall into this category.

A million cycles @ 80% DOD is the same as 1 cycle @ 100% DOD if they BMS doesn't cut out before 80% DOD. In Sony's case they never exceeded 90% DOD - but they had some cool fires when it got close (solution was to shut down equipment @ 80% DOD).

Were Sony using LiPo or LiFeP04?
I don't see why a LiFePO4 battery would be more likely to catch on fire at 90% discharge rather than 80% of discharge...unless you were charging it with an uncontrolled source and that at 90% DOD the recharge current was much higher than at 80% discharge - which again doesn't make sense?

The early LiFePO4 Cells were far more likely to brick at 90% discharge than 80% discharge, but this is an area that cell manufacturers have recently claimed improvements in (Yes I am sceptical). The claim is that their cells can now withstand greater Depth Of Discharge and also a higher number of these high Discharge Cycles. Obviously with a microprocessor controlled BMS with a low voltage discharge disconnect, you could set the level to suit the robustness of the cells that you were using. So you might start at 80% and later decide either you were too conservative and or that cell technology improvements now allowed you to go to 95% discharge or vice versa.

[avgas]

Like you I have a degree of scepticism of MTBF claims, that are calculated or manufacturer only claims. Hence my reason for being more interested in actual field results.

I think that even if you were given the circuit diagram of the BMS you still wouldn't be able to calculate the MTBF. I think what counts for customer confidence is what customers really experience. For many people only seeing is believing....I think I fall into this category.

Were Sony using LiPo or LiFeP04?
I don't see why a LiFePO4 battery would be more likely to catch on fire at 90% discharge rather than 80% of discharge...unless you were charging it with an uncontrolled source and that at 90% DOD the recharge current was much higher than at 80% discharge - which again doesn't make sense?

The early LiFePO4 Cells were far more likely to brick at 90% discharge than 80% discharge, but this is an area that cell manufacturers have recently claimed improvements in (Yes I am sceptical). The claim is that their cells can now withstand greater Depth Of Discharge and also a higher number of these high Discharge Cycles. Obviously with a microprocessor controlled BMS with a low voltage discharge disconnect, you could set the level to suit the robustness of the cells that you were using. So you might start at 80% and later decide either you were too conservative and or that cell technology improvements now allowed you to go to 95% discharge or vice versa.

MTBF - I think you find its calculated off the failure rate of the components. The killer used to be electrolytics - which would leak into PCB within 10 years dragging the MTBF. The only reason why manufacturers do burn in tests is to check pre-calculated MTBF's. I had major issues about 7 years ago when Siemens moved non-leaded solder - but MTBF remained the same. Turned out they (with most electronic manufacturers) don't bother to check components MTBF if the product code is the same.

Nah, I don't think Sony were using LiPo's - but it was the BMS that usually caught fire. LiIons exploded...........generally launching about 4G into the air. This was more a hot-burn-off. So the finger was pointed at what was attached to the cells rather than the cells themselves.

Don't take too many of my posts to heart. I cut my engineering teeth on (german) power system protection (much to the stress of my wife) and was anally retentive ever since. But at the end of the day I am my own biggest hypocrite - sometimes I still wire shit up with a "she'll be right" attitude. As boss once said to me "You'll conduct well here".

But yes I expect stats to equal. So if someone quotes me a million cycles @ 80% DOD I expect them to tell me the BMS would never allow 80% DOD.

[FastBikeGear]

MTBF - I think you find its calculated off the failure rate of the components.

Yes MTBFs are normally a calculated figure for predicting a failure rate. They are only accurate within narrow parameters

But we now have a couple of years of real world comparative reliability statistics ...and these are what we should pay most attention to.

But yes I expect stats to equal. So if someone quotes me a million cycles @ 80% DOD I expect them to tell me the BMS would never allow 80% DOD.

?? Sorry I don't understand what you are saying?

[FastBikeGear]

Deleted duplicate post.

[avgas]

?? Sorry I don't understand what you are saying?

10,000 cycles @ 80% DOD, but the BMS allows 95% discharge is the same as saying that you can ride this bike a million times @ 80% throttle, but your technically can ride at 95% throttle before the computer says no.

The result is that the computer doesn't prevent anything, and you don't get a million rides you get this first time you hit 95% throttle.


Likewise if you promise 10,000 cycles @ 80% DOD, but don't promise that BMS prevents 80+% DOD you are not exactly promising 10,000 cycles are you?
Soon as you hit 81% you could brick and get 1 cycle. (extreme example - I don't expect that at all)

Just saying its probably something like this:
X cycles at some peak point (80% DOD) then exponentially drops on either side of that figure. So if the BMS doesn't look after that (which I assume it does) then the stats don't exactly line up.

Unless there is a clause in the warranty that states its the owners responsibility to ensure 80% DOD to get the same number of cycles in the marketing. But I would expect the BMS to set this limit.

[bogan]

10,000 cycles @ 80% DOD, but the BMS allows 95% discharge is the same as saying that you can ride this bike a million times @ 80% throttle, but your technically can ride at 95% throttle before the computer says no.

The result is that the computer doesn't prevent anything, and you don't get a million rides you get this first time you hit 95% throttle.


Likewise if you promise 10,000 cycles @ 80% DOD, but don't promise that BMS prevents 80+% DOD you are not exactly promising 10,000 cycles are you?
Soon as you hit 81% you could brick and get 1 cycle. (extreme example - I don't expect that at all)

Just saying its probably something like this:
X cycles at some peak point (80% DOD) then exponentially drops on either side of that figure. So if the BMS doesn't look after that (which I assume it does) then the stats don't exactly line up.

Unless there is a clause in the warranty that states its the owners responsibility to ensure 80% DOD to get the same number of cycles in the marketing. But I would expect the BMS to set this limit.

Ahh, but then you run into the problem of established benchmarks and user comparisons. 80% DoD is often quoted as a measure of cycle counts, a BMS that allows it to go to 95% compared to a BMS that doesn't stop overdischarge at all, how do they compare them?

Would you say 5000 for the BMS one and 1 for the non BMS one? Or would you say 80% DoD and 10,000 for both? I know which one the BMSless guys would say, so then the BMS guys really need to give a similar number or look like they are lagging behind.

[avgas]

Would you say 5000 for the BMS one and 1 for the non BMS one? Or would you say 80% DoD and 10,000 for both? I know which one the BMSless guys would say, so then the BMS guys really need to give a similar number or look like they are lagging behind.

If the BMS allows for 95% DOD then quoting both @ 80% DOD is like comparing who is going to win a retard sprint.
The winner will still be a retard.
The BMS will still win, but will never achieve the figure quoted @ 80% DOD as it never cut off at that point.
So it would be wiser to quote how many cycles @ DOD cutoff wouldn't it? I mean that is why you have a BMS, isn't it?

FYI my bike can do 1,000 kmh @ 400% throttle.