2012 Stromer Elite update

[JoePah]

Turned 3000 miles and 2 years on my little electric bike and this is what i have to report:

Nothing. OK front tube, brake pads and chain were replaced.

No electric malfeasance of any kind. No disappointments or roadside quandaries.

Rode in the Florida a rain a bunch. Rarely ran it to low voltage cutoff.

Brought it to the dealer once for squeaky brakes and the battery was acting weird.. They ask me about it the bike now and then, and i just say it's fine.

Complaints?
Range on the battery is down around 20%, which is consistent with my previous electric bike, A2B Metro. About 10% per year.
Part of the reason might be that the battery was at least a year old when bought this leftover model. Probably will need a new one in a year or so.

I will say this Stromer has about 5% of the problems my A2B Metro had.. Same motor and controller I think..


I will keep this bike another year, sell it, and buy something faster and lighter.

 

[George S.]

https://transportevolved.com/2015/0...ur-nissan-leaf-loses-its-second-capacity-bar/

The capacity loss numbers are disappointing. I think the electric car batteries are holding up better, though this is just one person's experience. Same cells, more or less, inside the packs.

I finally decided to buy a charger that will charge to 80 or 90 percent, as well as a full charge. Works best with a bigger battery than I will need, most of the time. Less than a full charge won't be much of a problem. The evidence is pretty solid that this doubles the cycle life and slows the rate of degradation.

Two of the three kit companies I follow have gone this route (as an option). Not sure when/if a dealer type bike will include this kind of charger.

Overall, your experience sounds really good, to me. All you could want.

 

[JoePah]

https://transportevolved.com/2015/0...ur-nissan-leaf-loses-its-second-capacity-bar/

The capacity loss numbers are disappointing. I think the electric car batteries are holding up better, though this is just one person's experience. Same cells, more or less, inside the packs.

I finally decided to buy a charger that will charge to 80 or 90 percent, as well as a full charge. Works best with a bigger battery than I will need, most of the time. Less than a full charge won't be much of a problem. The evidence is pretty solid that this doubles the cycle life and slows the rate of degradation.

Two of the three kit companies I follow have gone this route (as an option). Not sure when/if a dealer type bike will include this kind of charger.

Overall, your experience sounds really good, to me. All you could want.

Like to know if that partial charging makes a difference. thanks

 

[JBJO]

Thanks for the update.. I am a new Stromer Sport Elite owner and I am surprised about the amount of trouble I am having finding information on this bike (It is new and did not come with a manual).... I am trying to absorb as much information as I can.. Albeit your post did not answer the many questions I have , I am however thankful to have found "something" in reference to it ....
Kind regards, JB

 

[JoePah]

I had to find the American and Canadian manuals on line.. They are both useful.

Since I'm a nuclear engineer everything is a project! I created a project book with the manual, computer codes, and receipts.

 

[JBJO]

Thank you very much !! That Manual is exactly what I have been unsuccessfully looking for ! I recently made the mistake of holding the "off" button too long and it locked the computer... After reading your manual I now realize the default unlock code is 1234.. So very frustrating prior to finding that out..
I am new to this forum and I dont want to intentionally clutter it with asking "questions" that are not pertinent to the title of the thread...
But , could I trouble you for information on the shocks ? What in the heck is that "speed lock" lever on the forks ??
I dont see any mention of it in the manual and the last time I was into bikes (30 years ago) we did not have levers on our forks
Many Thanks, JB

 

[JoePah]

YW... That suntour radon fork is a piece of junk. You can lock it out or get full suspension.. Check that the air pressure is around 140 psi.. One side is an air cylinder and the other is an oil filled damper... Just undo the black cap and you should see a schrader valve.. Use a quality digital readout to check and inflate it.

 

[gtawest]

Thanks for your update. It is encouraging to read that I'm not the only one who has had a fairly problem free ride with the 2012 Elite. I bought one this spring with 3000 miles on it (apparently without any electric related problems for the original owner) and have since put another two thousand miles on the bike. I've replaced the bottom bracket, had a tuneup including new brake pads and added a Brooks saddle and new pedals for comfort. It is a terrific, powerful ride and my only complaint is that the display clamp is broken and has to be taped on.

Because I live in a fairly flat area (Toronto), I find that I ride pretty much in the highest gear on Eco mode all the time and may convert the bike to a single speed for simplicity down the road. I am still on the original battery which gives me a range of about twenty five miles, so I'll probably replace that next year. I've read multiple posts on the newer St models being significant upgrades over the 2012 models, but the Avid BB7 brakes work great for the kind of riding that I do and I rarely change gears, so I wonder if it would ever be worth my while to upgrade to a newer model.

 

[Jack Tyler]

JoePah, re: your Q about partial charging extending battery life (or put differently, slowing the loss of battery capacity over time), so far I haven't found that supported by any of the battery technical articles and user blogs I've been reading. George, I know you've moved to an adjustable, partial-capacity charger, believing that will slow the loss of battery capacity. I'd welcome you filling us in on the references you found that validate this, as I've been looking for such evidence and so far can't find it. I have found multiple references to the damage done by fully charging the kind of lithium-based batteries used in most of these ebikes (LiFePO4) and then leaving the bank in charge, given the pretty basic (aka: cheap) chargers provided with ebikes. But to me that just argues in favor of a smart charger and charging to full capacity, not in favor or partial charging.

 

[JoePah]

Sounds like you're getting around @gtawest !

Contact Crazy Lenny in Madison WI when you need a new battery, and get the larger one.. He has the best prices that ive found.

I wouldn't touch the gearset unless it's giving you problems, then just replace with same. You should replace the chain ASAP if you haven't already... And the freewheel if the teeth are rounded.

Post a picture of your broken display clamp.. Pretty sure we can come up with a better fix.

 

[George S.]

JoePah, re: your Q about partial charging extending battery life (or put differently, slowing the loss of battery capacity over time), so far I haven't found that supported by any of the battery technical articles and user blogs I've been reading. George, I know you've moved to an adjustable, partial-capacity charger, believing that will slow the loss of battery capacity. I'd welcome you filling us in on the references you found that validate this, as I've been looking for such evidence and so far can't find it. I have found multiple references to the damage done by fully charging the kind of lithium-based batteries used in most of these ebikes (LiFePO4) and then leaving the bank in charge, given the pretty basic (aka: cheap) chargers provided with ebikes. But to me that just argues in favor of a smart charger and charging to full capacity, not in favor or partial charging.

Jack,

This is pretty densely packed information. There are two things, I suppose. How fully to charge the battery and how much to run it down. Obviously, if you charge to 80% and run down to 30%, you have half the battery. But you might get 4 times the life.

http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

The 100% is basically 4.2 volts per cell. At this voltage, there is more damage to the cells than, say, 4.1 volts. Since most people want range, they use the most aggressive charge, the highest voltage.

Thing is, these days packs are getting less expensive. And each cell holds maybe 3500 mAh versus 2500 a couple of years ago. You seem like a 'real world' kind of guy. Obviously, everything has to be taken into account. But the optimal charge for cycle life is 3.92 volts, or about 60%. At this charge, you might get 8 times more charge cycles. That's a huge difference.

 

[Jack Tyler]

George, I've read the Battery University entry you cited but their description of charge voltages vs. battery lifecyles - and their entire article - seems to be referring to the Lithium-ion Polymer (LiPo) type battery chemistry. (They really could/should be more specific about the Li battery chemistry they are addressing). Most folks (and so most battery articles?) focus on this more common battery chemistry because we find it in our cell phones and other consumer electronics. As I mentioned above, I was referring to the kind of Lithium battery chemistry that - my understanding, anyway - is more common for sustained, high demand, multi-cell use, and that's Lithium Iron Phosphate (LiFePO). This battery chemistry is more tolerant to 100% charging without a loss of potential battery lifecyles.

See e.g. http://www.powerstream.com/LLLF.htm
A LiFePO4 battery has a much wider overcharge tolerance of about 0.7V from its charging voltage plateau of 3.5V per cell. ...
A LiFePO4 battery can be safely overcharged to 4.2 volts per cell, but higher voltages will start to break down the organic electrolytes."
I thought Mark Wanger did a great job of outlining why LiFePO battery chemistry is such a good fit for ebike batteries.

I'm still learning about the 'electrical side' of ebikes, so surely not an expert. But Lithium battery chemistries do differ and it's important to zero in on the chemistry used by a given bike mfgr. (l'm not convinced Battery University is speaking conclusively to us.) Perhaps my faulty assumption is that many ebikes are not using LiFePO batteries these days?

 

[Ravi Kempaiah]

George, I've read the Battery University entry you cited but their description of charge voltages vs. battery lifecyles - and their entire article - seems to be referring to the Lithium-ion Polymer (LiPo) type battery chemistry. (They really could/should be more specific about the Li battery chemistry they are addressing). Most folks (and so most battery articles?) focus on this more common battery chemistry because we find it in our cell phones and other consumer electronics. As I mentioned above, I was referring to the kind of Lithium battery chemistry that - my understanding, anyway - is more common for sustained, high demand, multi-cell use, and that's Lithium Iron Phosphate (LiFePO). This battery chemistry is more tolerant to 100% charging without a loss of potential battery lifecyles.

See e.g. http://www.powerstream.com/LLLF.htm
A LiFePO4 battery has a much wider overcharge tolerance of about 0.7V from its charging voltage plateau of 3.5V per cell. ...
A LiFePO4 battery can be safely overcharged to 4.2 volts per cell, but higher voltages will start to break down the organic electrolytes."
I thought Mark Wanger did a great job of outlining why LiFePO battery chemistry is such a good fit for ebike batteries.

I'm still learning about the 'electrical side' of ebikes, so surely not an expert. But Lithium battery chemistries do differ and it's important to zero in on the chemistry used by a given bike mfgr. (l'm not convinced Battery University is speaking conclusively to us.) Perhaps my faulty assumption is that many ebikes are not using LiFePO batteries these days?

As a person pursuing doctoral degree in chemistry and materials science, I can chime in a bit....

Ok,

You have a cathode and anode and it is the Li-ions that shuttle between these two points. That space between them can be filled with different materials i.e., polymer (Li-polymer battery), Iron phophaste (LiFePo4 battery), Manganese cobalt (LiMnCo battery) etc.

So, you have all these chemistries but each have their own pro's and con's. Some are energy dense but # cycles will be less and some are more safer than others. So, for E-bikes, as of now, LiMnCo gives you the best of all: C-rate, energy density and charge cycles.
At 18-650 size, 4.2V is the upper limit. As you approach either end of the spectrum, the damage can be higher than linear.

If you know how the BMS is structured, then you can find a way to charge only 90% and prolong the life. It is a proven fact but given the space and weight constraints, most manufacturers ignore it and try to utilize the full capacity. The consensus is that, energy density is increasing rapidly. So, why bother with all this partial charge when you can have a better battery in few years!

 

[George S.]

Jack,

Ravi knows more than I do, and I try to stay with fairly practical stuff. Not to disagree with Ravi, but you could see an economic tradeoff where they would not use some of the capacity for longer and more predictable capacity losses. In particular, I doubt that electric car companies can avoid using 80-90% charges in their battery systems, because of warranty costs and the need to 'sell' a 10 year battery system. The standard ebike cells, like the Samsung and Panasonic, LG, are benefiting from the money going into electric car production. It's like the Tesla Gigafactory. Musk wants the price per kWh down to below $200 in 2016. GM says the Bolt is based on $145 per kWh, and they are linked with LG. You translate that into ebike batteries and the costs almost stop mattering, especially for $4000 and up bikes.

I like LiFePO4 batteries, but they are becoming obsolete. I've had two for ebikes and both have worked, or continue to work, flawlessly. I own one now, and sold one with a Prodeco bike. The packs are big and heavy, relatively speaking. The LiFePO4 are generally big pouches in series, and each cell has less energy, less voltage, so you need more for a given pack and voltage. They are tolerant of overcharge and they have long cycle lives. But the cost of 18650 chemistry has dropped, and the densities have increased.

I bought a 48v 13.6 AH pack that I hope to use for a couple of years. It weighs 7 pounds and the pack is quite slim. No downside to me buying a higher capacity pack, more than I need generally, and charging it to 90%. I charge the LiFePO4 pack close to full, but they pretty bulletproof.

You generally will find LiFePO4 as a blue or black Shrink wrap package, like a 'brick'. The prices are very low, like $250 for a 36v 15 ah, from China. All the LiFePO4 pouches may be made in China, unlike the quality 18650 cells.

I'm an advocate for converting bikes. It's what I like. So you buy a battery and you buy a motor, basically. There are more opportunities to find good batteries, or maybe good prices, in the kit or conversion market, and you are not locked in to anything proprietary. There are certain kinds of builds where a LiFePO4 is still a solid choice at an unbelievable price. But the high density cells are much closer in price, right now.

 

[Jack Tyler]

Excellent info. Thanks to you both.

Ravi, you could tell I didn't think Battery University was the be all/end all on this subject. Can you perhaps provide us all with an on-line reference or two that might be more relevant to the LiMnCo chemistry that you describe as more relevant to the current ebike market?

George, I wouldn't argue with your current approach regardless of the chemistry. Buying more capacity than you require would certainly future-proof your choice.

 

[J.R.]

Hey @Jack Tyler

I have a bike with a LifePo4 and it is probably 25% heavier than a comparable battery of better chemistry. Big too, but stable, safe and will withstand up to 2000 charge cycles. I don't think they're obsolete though, they will be used for many applications, just too heavy for ebikes.

I don't think my LiMnCo battery on the 29'er does as well in the cold as the LifePo4 does, but that's anecdotal and maybe premature to say at this point. We haven't had as much cold here in PA as normal. Last year in the coldest winter we've ever had I rode 3000 miles between October and April, on the coldest days I lost 15% range with the LifePo4, maybe 15-20% with LiMnCo. That's not definitive at this point. I tell you about the cold because I know you'll be riding in Bozeman.

I don't think Battery U is wrong, just needs updating in many areas. I found old data there just last week. I know the info was out of date because I found up to date information at the original source. So much changes with batteries, so fast, I would not want to be their web-master.

This is a fairly good concise paper on batteries as they relate to ebikes. It was written for 2013, but the information is still current. https://www.electricbike.com/lithium-cobalt-manganese/

I probably fall into the 'I'll replace it before it's dead' camp. From the research I've done, it's far worse to run a battery down than it is to charge to full. I charge to full whether I ride 5 miles or 40 miles. I If I had a $300 programmable charger, I might use it, if I was sure the cells balanced properly. I don't think BH or PT are going to provide that information. Maybe someday ebike companies will install a BMS that will do that for us.

 

[Jack Tyler]

Thanks, J.R. - more grist for the mill, since you're reporting experience with the two chemistries I seem to be hearing about. Very helpful. We can see e.g. why Ridekick chooses LiFePO4 chemistry: the weight isn't as important for their product and the cycle life gain is beneficial.

I don't consider Batt Univ 'wrong' so much as blending generic Li info with LiPo info. That no doubt works for most consumers and most content, but when specs like max viable cell voltages are cited, being clear about the chemistry would be more helpful. To me, at least.

Good discussion.

 

[George S.]

I have a bike with a LifePo4 and it is probably 25% heavier than a comparable battery of better chemistry. Big too, but stable, safe and will withstand up to 2000 charge cycles. I don't think they're obsolete though, they will be used for many applications, just too heavy for ebikes.

@J.R. I think Prodeco is keeping the X3 and using a Samsung pack, now. Not really Stromer news.

 

[JoePah]

I would like to see some real world results from one of us to convince me that battery packs on eBikes significantly benefit from a lower charging cycle.

There something about leaving my house on a trip with 80% charge! lol can't do it...

 

[gtawest]

Sounds like you're getting around @gtawest !

Contact Crazy Lenny in Madison WI when you need a new battery, and get the larger one.. He has the best prices that ive found.

I wouldn't touch the gearset unless it's giving you problems, then just replace with same. You should replace the chain ASAP if you haven't already... And the freewheel if the teeth are rounded.

Post a picture of your broken display clamp.. Pretty sure we can come up with a better fix.

Thanks for the input Joe! That's probably a good idea to leave it factory spec and the chain/freewheel both checked out ok by my mechanic, so I assume that they were replaced by the previous owner.

I'll post some pics of the broken clamp on the display under a separate thread.

Doug.