Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Electric Bikes Here's a place to discuss ebikes, from home grown to high-tech.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 09-27-12, 10:53 AM   #1
Burton
Certified Bike Brat
Thread Starter
 
Burton's Avatar
 
Join Date: Jan 2011
Location: Montreal, Quebec
Bikes:
Posts: 4,251
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Actual battery life of LiFeO4 and Lithium batteries

These battery technologies are being touted as being able to be recharged 1000 to 2000 times (Lithium and LiFeO4) which, even if they were charged / discharged every day / 365 days per year - should give a life expectancy of 3 to 6 years. Thats NOT what I'm seeing customers get. Its more typically 2 years before a new battery is needed. Trouble shooting usually confirms that only a couple cells are the issue, but cells aren't sold individually - ya gotta buy the whole battery.

Those batteries are expensive and buying a new battery every couple years isn't exactly what most customers expect to have to do - especially if the bike has only seen light use.

What are your own experiences please?
Burton is offline   Reply With Quote
Old 09-27-12, 11:21 AM   #2
spirit733t
Senior Member
 
spirit733t's Avatar
 
Join Date: Jun 2012
Location: West Midands, England
Bikes: Saracen Killi Chromo 2
Posts: 127
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
good post, Id like to see this as well, I am about to buy a PING battery.. and would love to hear people long term experience..
spirit733t is offline   Reply With Quote
Old 09-27-12, 03:25 PM   #3
FMB42
Senior Member
 
Join Date: Sep 2010
Bikes:
Posts: 454
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Ya, good question for sure. My experience with lead acid, NiCd, NiMh, and Lipo batteries is that the factory claimed cycle numbers represent "ideal" conditions. High load, high heat, and over/under charging conditions (if excessive) can result in reduced battery life. A case in point is an RC helicopter NiMh battery that I ruined by over-charging it. This battery was still running strong after more than 225 cycles before I damaged it (the factory claimed 200 -250 cycles IIRC). Another thing worth mentioning is that you should always, imo, allow your battery to cool down to "room" temp before and after charging (i.e. don't charge it up when it's hot and don't charge it and then run it without letting it cool for a bit).
FMB42 is offline   Reply With Quote
Old 09-27-12, 06:44 PM   #4
rscamp
Senior Member
 
rscamp's Avatar
 
Join Date: Jun 2008
Bikes:
Posts: 251
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Charge/discharge cycle depth, storage SOC and temperature, passage of time, charge/discharge rates, all conspire to reduce the afore-mentioned laboratory cycle life. The effects of these are so great that I think that how the batteries are treated in real world applications makes battery cycle life performance specifications a form of fiction. They are almost always unachievable and only the roughest of guidelines for comparison.
rscamp is offline   Reply With Quote
Old 09-29-12, 08:15 AM   #5
15rms
Senior Member
 
15rms's Avatar
 
Join Date: Oct 2007
Bikes:
Posts: 285
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
My sons 30 amp 24 volt ping battery is still going strong after 3 years. Not totally 100% however very close. I was told by a maker of ebikes lithium will lose between 5 to 8% a year.
15rms is offline   Reply With Quote
Old 09-29-12, 04:17 PM   #6
Burton
Certified Bike Brat
Thread Starter
 
Burton's Avatar
 
Join Date: Jan 2011
Location: Montreal, Quebec
Bikes:
Posts: 4,251
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Quote:
Originally Posted by 15rms View Post
My sons 30 amp 24 volt ping battery is still going strong after 3 years. Not totally 100% however very close. I was told by a maker of ebikes lithium will lose between 5 to 8% a year.
A 30Ah battery is HUGE! Capacity wise anyway! Most ebike batteries typically run around 9Ah. So how often did he drain it completely and how often was it charged? Did he top it up regularly wheither it was completely drained or not?

My own battery is a 9Ah 36V and I only drain it completely ocassionally, top it up without waiting for it to drain fully, and thats about 3 times a week. So far two years and everything looks OK but have yet to confirm actual range this year. Initially it was good for about 35km at 30km/hr.

There are currently 20Ah 36V batteries available but $1,400 is ridiculous if it won't last more than 2 years.
Burton is offline   Reply With Quote
Old 09-29-12, 04:24 PM   #7
15rms
Senior Member
 
15rms's Avatar
 
Join Date: Oct 2007
Bikes:
Posts: 285
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
"how often did he drain it completely and how often was it charged? Did he top it up regularly wheither it was completely drained or not?"

I doubt if he ever drained it completly. He does ride sometimes up to 50 miles he turns off the electrics and peddles. He does top it off regularly and took good care of it over the winter. It pays to take good care of your battery and as expensive as they are there is good insentive to do so.
15rms is offline   Reply With Quote
Old 09-29-12, 06:46 PM   #8
Scaliboy62
Senior Member
 
Join Date: Dec 2011
Location: Florida west coast
Bikes:
Posts: 227
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Burton, that 20 AH $ 1400.00 battery could easily provide 20,000 miles of commuting in that 2 years, a car that gets 20 MPG, driven 20,000 miles @ $ 4.00 a gallon for gasoline = 4000.00. But I understand your point 1400.00 is a lot for a battery that only lasts 2 yrs. { maybe it comes with a 4 year warranty **
Scaliboy62 is offline   Reply With Quote
Old 09-29-12, 08:06 PM   #9
Burton
Certified Bike Brat
Thread Starter
 
Burton's Avatar
 
Join Date: Jan 2011
Location: Montreal, Quebec
Bikes:
Posts: 4,251
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Quote:
Originally Posted by Scaliboy62 View Post
Burton, that 20 AH $ 1400.00 battery could easily provide 20,000 miles of commuting in that 2 years, a car that gets 20 MPG, driven 20,000 miles @ $ 4.00 a gallon for gasoline = 4000.00. But I understand your point 1400.00 is a lot for a battery that only lasts 2 yrs. { maybe it comes with a 4 year warranty **
The particular battery I have in mind is marketed by Velec here in Quebec, but made in China according to their specs. The warranty is 18 months - and riding season here is really only 8 or 9 months. Realistically the battery might get you 80km or a 40km round trip - but we're really only talking about 4 hours of continuous use before it needs to be recharged.

So yup - if driven every day for 4 hours you could actually do 20,000 miles per year. But most people don't do that much driving - either in a car or with a bike. So the real question I'm asking myself is - can I really justify $700/year for a battery when I have half a dozen other bikes that see just as much use and don't need batteries? My own commute is about 13km and takes about 25 minutes regardless of what I drive.

I have ebikes myself primarily so I can get a first hand perspective from a customers point of view. For any individuals retired and on a fixed income (as are a lot of the clientele on ebikes) I can see where the extra autonomy would be nice, but the cost hard to justify.

The realistic way to decide would be to calculate the actual kimometers driven and then work out a cost per kilometer based on battery cost and life. In my case that would be no cheaper than taking the bus or ... buying a new bike every year

Last edited by Burton; 09-29-12 at 08:18 PM.
Burton is offline   Reply With Quote
Old 09-29-12, 08:20 PM   #10
turbo1889
Transportation Cyclist
 
turbo1889's Avatar
 
Join Date: Aug 2011
Location: Montana U.S.A.
Bikes: Too many to list, some I built myself including the frame. I "do" ~ Human-Only-Pedal-Powered-Cycles, Human-Electric-Hybrid-Cycles, Human-IC-Hybrid-Cycles, and one Human-IC-Electric-3way-Hybrid-Cycle
Posts: 1,206
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Quote:
Originally Posted by Burton View Post
These battery technologies are being touted as being able to be recharged 1000 to 2000 times (Lithium and LiFeO4) which, even if they were charged / discharged every day / 365 days per year - should give a life expectancy of 3 to 6 years. Thats NOT what I'm seeing customers get. Its more typically 2 years before a new battery is needed. Trouble shooting usually confirms that only a couple cells are the issue, but cells aren't sold individually - ya gotta buy the whole battery.

Those batteries are expensive and buying a new battery every couple years isn't exactly what most customers expect to have to do - especially if the bike has only seen light use.

What are your own experiences please?

This is EXACTLY the very reason that for my first LiFePO4 build I did not use a Ping batter or any other similar non-repairable battery (not picking on Ping). I personally strongly suggest the use of fully repairable battery packs built from international standardized screw terminal cylinder or prismatic cells. Although a select few battery packs built for bikes do use such cells and are fully repairable you are must more likely to find them for a reasonable price by buying from a place that is more geared towards the solar and off-grid power systems market. I'm using two of these packs wired together to run my 24V cyclone mid-drive motor:

http://www.batteryspace.com/lifepo4b...erstorage.aspx

And these are the cells inside the pack that if one fails you can replace them with:

http://www.batteryspace.com/LiFePO4-...ate-64-wh.aspx



I would also note that from my understanding it is correct that the rated number of cycles by the manufacturer is a "best case scenario" but it is also true that they are correct for relative comparison. Or in other words if LiFePO4 technology is rated to take twice the number of cycles then some other battery technology under harsher conditions yes the life will be shorter but the relative double lifetime is still correct since the other lower life technology will also be shorter due to the abuse.
turbo1889 is offline   Reply With Quote
Old 09-29-12, 10:20 PM   #11
Scaliboy62
Senior Member
 
Join Date: Dec 2011
Location: Florida west coast
Bikes:
Posts: 227
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I wonder how many of us E-Bikers who either bought factory built bikes or did a kit bike have batteries that can be opened up to have the cells replaced ?
Mine looks like it's easy to open up, heck can save a nice chunk of change..I hope mine is servicable
Scaliboy62 is offline   Reply With Quote
Old 09-30-12, 12:18 AM   #12
Burton
Certified Bike Brat
Thread Starter
 
Burton's Avatar
 
Join Date: Jan 2011
Location: Montreal, Quebec
Bikes:
Posts: 4,251
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Quote:
Originally Posted by turbo1889 View Post
This is EXACTLY the very reason that for my first LiFePO4 build I did not use a Ping batter or any other similar non-repairable battery (not picking on Ping). I personally strongly suggest the use of fully repairable battery packs built from international standardized screw terminal cylinder or prismatic cells. Although a select few battery packs built for bikes do use such cells and are fully repairable you are must more likely to find them for a reasonable price by buying from a place that is more geared towards the solar and off-grid power systems market. I'm using two of these packs wired together to run my 24V cyclone mid-drive motor:

http://www.batteryspace.com/lifepo4b...erstorage.aspx

And these are the cells inside the pack that if one fails you can replace them with:

http://www.batteryspace.com/LiFePO4-...ate-64-wh.aspx



I would also note that from my understanding it is correct that the rated number of cycles by the manufacturer is a "best case scenario" but it is also true that they are correct for relative comparison. Or in other words if LiFePO4 technology is rated to take twice the number of cycles then some other battery technology under harsher conditions yes the life will be shorter but the relative double lifetime is still correct since the other lower life technology will also be shorter due to the abuse.
I'm guessing that you have an advantage living in the USA. International shipping by mail of lithium batteries is getting more and more restricted. I'll have to ask if they'll actually ship to Canada and what the additional charges will be.
Burton is offline   Reply With Quote
Old 09-30-12, 10:54 AM   #13
turbo1889
Transportation Cyclist
 
turbo1889's Avatar
 
Join Date: Aug 2011
Location: Montana U.S.A.
Bikes: Too many to list, some I built myself including the frame. I "do" ~ Human-Only-Pedal-Powered-Cycles, Human-Electric-Hybrid-Cycles, Human-IC-Hybrid-Cycles, and one Human-IC-Electric-3way-Hybrid-Cycle
Posts: 1,206
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 10 Post(s)
Quote:
Originally Posted by Burton View Post
I'm guessing that you have an advantage living in the USA. International shipping by mail of lithium batteries is getting more and more restricted. I'll have to ask if they'll actually ship to Canada and what the additional charges will be.

Actually, strictly speaking in terms of battery and other e-bike components shipping cost I would probably be best off living somewhere in Eastern Asia where all that stuff seems to be mostly made !!!

That said there does appear to be two different classes of lithium technology batteries UN approved and non-UN approved. I have no idea what exactly they are approving or not approving or whether it be a bribe under the table situation for the battery manufacture to get their particular cells approved or if it meets certain standards or what but shipping the approved variety seems to be cheaper and not just on that web-site I have seen two different shipping rates for UN-approved vs. non-UN-approved on other sites as well. So I don't know what it is all about and why it matters but it does seem to matter for shipping cost.

I'm also not specifically recommending the particular battery pack I linked too since it may not be right for everyone's build like it was for mine. What I'm saying is get the repairable type packs made from either cylinder or prismatic cells with screw on terminals. Heck if you are the real handy type you could even just buy the cells alone and wire them together yourself in your own battery box building your own pack from scratch. That is what I did with all my previous NiMH powered builds since the cheapest way to get good quality NiMH cells is to buy industrial grade sub-C cells in bulk quantity and then build your own pack from them, same does not necessary hold for the lithium packs but its worth a look if you think your up to the challenge.
turbo1889 is offline   Reply With Quote
Old 10-02-12, 08:26 AM   #14
Burton
Certified Bike Brat
Thread Starter
 
Burton's Avatar
 
Join Date: Jan 2011
Location: Montreal, Quebec
Bikes:
Posts: 4,251
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
OK - so here's some info I picked up yesterday at the Velec headquarters here in Montreal, where dealers from around the province were invited to test drive the 2013 models.

(1) The highest milage actually recorded from a Velec battery to date is 37,000 kms. The battery saw fairly continuous use and was being cycled on a regular basis.
(2) There have been a number of reliability issues associated with either the BMS or the cells of battery packs sourced directly from suppliers in China - with hundreds of batteries being warrantied every year at worst.

To resolve the reliability issue, improve customer service and continue in an effort to establish a reputation for reliability, all Velec batteries for the past two years have been sourced directly from Panasonic. Last year there were only three warranty cases.

(3) The chemistry of the main battery is now Lithium and not LiFeO4. Although in theory Lithium has fewer life cycles, customers here will not achieve even the full number of cycles of a Lithium battery during its five year life expectancy - therefore the additional cycles provided by LiFeO4 was unnecessary overkill.

Last edited by Burton; 10-02-12 at 08:34 AM.
Burton is offline   Reply With Quote
Old 10-28-12, 09:34 PM   #15
DrkAngel
Senior Member
 
DrkAngel's Avatar
 
Join Date: Oct 2012
Location: Upstate NY
Bikes: Various "modded" eZips and multiple econversions
Posts: 336
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Lightbulb Optimizing Lithiums

Prolonging, or diminishing, battery life is accomplished by considering several factors.

1st - Battery type-formulation?
Various types perform differently.

2nd - Optimal, charge-discharge, rates.
If your Lithium batteries heat up, either during charging or discharging, you are losing efficiency and damaging capacity and longevity.
Most common in the RC airplane world, 30C rated batteries, used at near rated, often only supply a mere 50 usable cycles.
The same batteries, run at a modest .5C - 3C will supply hundreds ... and possibly, more hundreds of usable cycles.
Carefully monitoring temperature during various charge and discharge rates might help you target ideal rates.
A 20Ah pack , discharging at 1/2 the rate, might give you 3x the cycles of a 10Ah pack.
Plus double the range, as a bonus.

3rd - Optimal, peak and minimum, voltages.
Higher peak charge voltage and lower discharge voltages can greatly diminish a packs lifespan.
Different formulations have different "optimal voltage ranges".
I have "capacity mapped" multiple LiPO batteries.
One type measured nearly 90% capacity between 3.7V - 4.1V.
Another type showed good energy density from 4.2V right down to ~3.4V.
If you operate outside the batteries optimal voltage range ... you are causing excessive degradation, for little to no additional Ahs. Also causing excessive battery "wear & tear" = damage.

I have been building, using, repairing Li-ion battery packs for the past 4+ years.
One of my favorites is the 25.9V 31.2Ah build that fits inside an eZip "RMB" removable pack.
Compare this to the oem 24V 10Ah ... with a pitiful 6.14Ah usable, (during a 1hr discharge).



Oh! ... and I built the pack using recycled laptop batteries!
Attached Images
File Type: jpg EZip 31.2ah Liion.jpg (101.6 KB, 88 views)
File Type: gif jpg.gif (183 Bytes, 85 views)

Last edited by DrkAngel; 10-30-12 at 02:15 PM.
DrkAngel is offline   Reply With Quote
Old 10-30-12, 08:42 AM   #16
DrkAngel
Senior Member
 
DrkAngel's Avatar
 
Join Date: Oct 2012
Location: Upstate NY
Bikes: Various "modded" eZips and multiple econversions
Posts: 336
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Lightbulb Not NiCd!!!

I run into this all the time.
1st with Lead Acid batteries ...
People insist that batteries must be fully drained to maintain full capacity.
WRONG!
Deeply discharging SLA (Sealed Lead Acid) quickly and irreversibly damage the batteries.
Lead Acid batteries should never be deeply discharged, they should be charged often and as soon as possible!

They must be half remembering admonitions about NiCd batteries?

Similarly, with Li-ion batteries, some believe they should fully discharge the cells.
Deeply discharging is "damaging".
Most all, Lithium technologies appreciate frequent recharging.
However ... much deterioration occurs at peak charge, or "overcharge".
Limiting top and bottom voltages to 80% of capacity is reputed to double the lifespan!
(Lowering peak charge and limiting discharge)
Another factor is that rapid discharging and charging rates are definitely "damaging"!

Just because a battery is rated as 20C capable ... doesn't mean that it is good for it!

Doubling battery size would reduce discharge rate, greatly increasing pack durability ...

So ... invest in, and care for, a larger pack or buy a small pack and use it up? ... FAST!

Last edited by DrkAngel; 10-30-12 at 08:07 PM.
DrkAngel is offline   Reply With Quote
Old 11-13-12, 05:16 PM   #17
dunningham
Newbie
 
Join Date: Nov 2012
Bikes:
Posts: 2
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Hi-I've had mine for a year and used it fairly extensively-so far so good but I am wary of the quoted lifespan and would be very displeased if I had to replace after two years. I do wonder if I'm getting quite the range I had initially but havn't tested it thoroughly.
dunningham is offline   Reply With Quote
Old 12-21-12, 03:22 PM   #18
Kevin Harvey
Senior Member
 
Join Date: Jun 2012
Bikes:
Posts: 64
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
i Buy cells off http://www.bmsbattery.com/ & BMS use their pack or make up pack -must use thingy to get BMS big enough for current ---cells are then replaceable- 2 other web sites am trying out they can get a bad name(thanks to the guys who started this) on these forums if they don't front up.
Kevin Harvey is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 01:05 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    get answers from real people!
Click to start entering your question.
I HAVE A QUESTION