Well, It's been awhile since I've ranted on this site. Since then, I've got my pair of battEQ's and installed them on the pair of already highly imbalanced lead-gel battery strings. They "seem" to keep the speed more constant than without them, I have noticed, as far as extending the life of the battery, I can't comment because the batteries that come with this bike are absolute garbage.
Here's the timeline of events if anyone is interested in the quality and durability of this bike:
- Purchased july 2007
- 1st time charging bike, 10amp charger failed and had to ship back.(defective xianji relay inside unit i suspect, since there was a burn mark on it.)
- purchased low current 48 volt SLA chargers from online store for real cheap. Worked like a champ.
- Tried to get refund of 250 dollars for charger. Got replacement 4 months later which also died after first charge. Did I mention I found a 48volt 5 amp charger online too which was DOA? That's just beyond pathetic. Why bother even making them.
- Anyway the only chargers that worked are the original e-max chargers (made in germany)I found on ebay and the 2.5amp 49.99 chargers I mentioned before.
- November I finally got my title and got a license.
- June 2008: melted the first string of batteries by discharging them as far as they could possibly go. Range is now down to about 8 miles. Installed battEQ units.
My conclusion:
pros:
- This is a wonderful little bike. I simply adore it. Max range on new batteries was almost 30 miles going about 30 mph. I've easily maxed the bike at 43mph on a straight road. It's comfy, generally quiet and fairly well built. 1/2 penny a mile to operate. Get laughed at by monkey's in SUV's and hummer's, and loudly proclaim, "I'll have the last laugh...."
cons:
- Motor is somewhat noisy when first accelerating. Lead-gel batteries(silicone batteries) that come with the unit are horrible and mis-leading to customers since they are not really any different than (lead-gel) batteries. The "silicone battery" was a marketing deception to make people believe they were getting something different than lead batteries.
- The electric scooter industry doesn't take off because money is the number one thing that people seem to be motivated by. I don't see too many people getting into the EV biz simply because their heart is in it. The problem is people flock to this field because they think their going to get rich by doing so, and really don't care about the ramifications of our addiction to saudi oil and actually accomplishing the task of getting us off the stuff.
Right now it's pretty much too late to do anything to get this market going. What needs to happen is an open source type development process for every component of the EV, including the batteries, and if that means big corp xyz can't exercise their patent control on batteries that could be massed produced here in america, so be it. We have enough un-employed people right now to build all of the LiFep04 batteries we need for 10 million vehicles by next year. The whole "it's my patent, you can't have it" should not apply to energy devices, especially when were in this position, That's like einstein telling oppenheimer he can't make the atomic bomb because he has an exclusive patent on e=mc^2. That's the only way to open up the market to people who actually care about what they're doing, and about making a quality product without gauging the customer like a123 and all the other american based lifep04 makers. All I see is the same ole crappy capitalist greed based system of controls falling down on the EV market that does nothing but stall real progress. and by the time they finally figure out they can make these batteries here, the U.S. will be looking much like the remnants of the soviet union and people will most likely have to die. We've outgrown this system, it's pretty much useless to continue.
Anyway, I got a quote from valence, GP(used in vectrix) distributors, a123, for cells to build a custom pack. Valence was literally out of their mind on price. GP came in at around 2300 for the cells alone ordering in bulk and trying to haggle the guy down as far as he would go, a123 was not as bad as valence but still too high for this.
The best deal right now still looks like the odyssey pc680 agm batteries, they'll run a little over 1k and they are guaranteed for 3 years or 400 cycles. While at hybridfest last week, I asked around about (enersys) odyssey and only heard good stuff about them. I've noticed recently a large pickup of the online availability of generic lifep04 cells. I haven't tested any of the cells yet, but was hoping someone here already had so I wouldn't have to. Can anyone comment on these generics out there? Anyone have more than 1000 miles on one of those generic lifep04 packs here?
Hiya,
Ive been running lithium for the past 6 months and have done 6500km (3800mi) in that time.
my setup is 19 3.2v cells at 40AH for 60.8v on an emax.
The cells are thundersky.
the cells and BMS cost me $4000AUD ($3700US)
If i were to add it to a group buy (like i did for the cells for my car) this price would come down to $2000AUD ($1800US)
I bought them so i could have a real life long term test with them before i scale up to a car.
things to note:
voltage drops 0.2v per C of loading. my average load is 40A, so i see 57v usually (3x19)v.
over discharging and over charging kills these cells really fast, so use an AH counter to gauge how much you have drawn.
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
So you've got the 60volt setup and your running them just as I am: 40amp pull over 1hr. Good. I haven't done the 60 volt conversion and don't really feel I need to.
Could you define over-discharging the cells? Is that running them @ 60%DOD, 80%DOD,?
I will be running the batteries daily @ 70%DOD. I don't expect them to last forever, but at least 20,000 miles or 400-600 cycles. Do you know of a reasonably priced ah counter I can fit on this bike just off the top of your head? That would be a good idea.
Thanks for the info, good stuff.
If you dont need 60v, then i wouldnt bother, just make sure your BMS can handle it in case you decide to go 60v later on.
If you are staying at 48v, make sure you get 16 cells not 15 as i originally did.
16cells will give you the full 48v under load.
Overdischarge is 100%dod or more. ideally dont go beyond 90%.
at 1C the thundersky lfp40 cells are 36AH@100%dod.
70% daily should be fine, mine are cycled to 40%dod twice a day, when im in uni holidays and 60%dod once a day and 40% once a day when im at uni.
Ive used 3 different measurement devices on my emax before.
I originally used a wattsup meter (US$70) but it only had an internal shunt so it had to be mounted inline with the main power line away from where i could see it while riding. Ive heard of someone who has modified it to make the shunt external, cant remember where though.
I replaced the wattsup with a cycleanalyst ($US150), as this has a remote shunt, and a whole host of other features.
For a while i used a Paktrakr (US$500), however it caused balance issues, and didnt count AH. If you do buy one of these, dont leave it connected 24/7.
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
Bruce_Wayne,
I agree that "intellectual property" laws have gone too far - People are event trying to patent laws of physics, and copyright math expressions. And most patent holders are corporations far removed from the actual inventor. Patents are bought and sold and arbitraged just like stocks.
But you are right, there should be compulsory licensing for patents for devices that could address that affect critical environmental or energy security energy issues, just like poor countries that tell big Pharma to go to hell and compulsory licensing AIDS drugs. Next step - throw the whole corporate scam called the WTO on the trash can.
Back to the e-max - If you haven't already, give my piece on upgrading my e-max to Thundersky a look. While still not cheap, I did my upgrade for somewhat less. 16 cells plus still a couple of the better condition 20AH lead acid for switchable 60V use. A good BMS solution (in kit form) is on the way. Go here: http://endless-sphere.com/forums/viewtopic.php?f=14&t=5416&st=0&sk=t&sd=a&start=135
Something has stopped my thought process on this, and I'll tell you what:
My price point is under 2k. So... It's either the pc680 odyssey agm's with my 4 12v battery string BattEq's to balance the voltages, or, and this is where I get stuck. I would prefer the prismatic nimh packs from a reputable company and cells that have already been proven, like the 7.2 volt 6.5 ah cells that make up the toyota prius pack. I can get one off ebay for less than $600 , that will give me around 25ah and 50 ah with two, but the voltage will be higher, 50.4 nominal. Here's where I get stuck.
Where can I find a 48 volt nimh charger and how can I offset the extra 2 volts that will be evident in this pack. I know this will be a problem and the pack simply wont fully charge with a 48 volt delta v charger if I could even find one reasonably priced. I've found one, but it's clearly being sold with the intention of gauging rich folks, which I am not. Does anyone know where I could get a variable charger that does all the delta charging modes for nimh? I'm asking for a miracle here.
The BMS shouldn't be that tricky, I see on the link you posted, gary is working on a bms for 3.6 volt cells. I Don't think It should be that tricky to modify this design for 7.2 instead. The charging issue is where I clearly get stuck, It's hurting my head thinking about it. Can anyone out there give me an idea about what to do with the charging problem for this hypothetical pack?
Hi Bruce,
Im surprised a Nimh pack wouldnt come with a battery charger?
what BMS does it use?
do you have a link to the specific pack you are refering to?
The TS cells have fallen a bit since i bought the pack for my scooter.
If you join a group buy you can get cheaper cells, though i dont know of any group buys happening in the states.
Maybe join the Thundersky yahoo group and find out.
Here downunder i participated in the last group buy and the price was quoted as $1.62/AH (AUD) per cell (the cells themselves were $1.20/AH per cell (US$), the rest was shipping and duties).
I was told yesterday my cells had arrived in the nearest port and id be expecting some of my money back as the actual price was lower than expected.
Other options is to try the foil pouch type cells on ebay. people over at the endlesshpere forum have been getting good results with these batteries.
They arent particularly high rate (only around 2C) but in you have a 40AH pack thats 80A.
48v 40AH will set you back about $1200 including shipping BMS and charger.
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
Bruce,
Patrick Rentsch, in the SF Bay area has been selling charge-cycle-tested 40AH Thundersky cells for $87 each, including shipping. Gary Goodrum's battery management board kits are now available, for $89.00 plus a few dollars shipping.
http://www.tppacks.com/products.asp?cat=26
So, adding an extra $100 for incidentals, and assuming you have a bit of soldering skills, you can upgrade to LiFePO4's for less than $1600.
PM me for Patrick's contact info.
Matt,
Was that $1.20 per AH or WH? 1.20 per AH per cell would be only $48 per cell. That is unbelievably cheap!
I was refering to this:
ebay item Toyota Prius Hybrid Battery Pack OEM
I don't think two full packs broken down will even fit on my scooter anyway. I wasn't really looking to destroy my battery compartment either. I'm curious, Do you really get that much performance increase with a 60volt output? Max speed, honestly.
I'm assuming this was done with a dc to dc converter?... The only way I see it unless you want to add a 5th battery.
This is most likely what I'll be doing this week:
http://www.septechnologies.biz/index.asp?PageAction=VIEWPROD&ProdID=448
Hook up my battEQ's and order up a cycle analyst, which is very useful BTW. Thanks for mentioning it matt. I realize this config will be 30 lbs heavier, but it's a trade-off I'm willing to make.
I'll post some pictures soon.
regards
Although lithium does entice and grab me, for all the same reasons it does you, I'm not sure I trust anything like this out of china anymore. I will do some measuring tommorow and decide afterwards exactly what I can fit in my bike for sure before I spend a dime. These batteries come with a 3 year full replacement warranty as well and they will cost me half of what the lifep04 packs do.
How many miles have you put on your pack and have you noticed a decrease in range or performance yet?
PJD,
having had a second chat with the group buy organiser,
i think we got the price down to US$1.10/AH/cell ex factory.
so you have to add shipping and duties to that.
we were buying a fairly large amount of batteries (think sea container).
i personally bought 90 x 90AH + 4 x 40AH for my mr2, a friend bought 220 x 40AH for his ute, another friend bought 80-90 x 200AH units for a couple of conversions he had going on, and so on. we ordered some extras i think because people kept changing their minds as to what they wanted.
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
If you can get Nimh cheaper with bms and charger, id just go with nimh.
that warranty is good.
I killed one of the cells on my setup by overdischarge (pulled 36AH out when the 1C rating is 36AH, the BMS keeps the pack within 1-2AH of being balanced, obviosuly this cell was slightly lower than the rest).
the rest are running fine though.
no capacity loss or extra internal resistance (other than temperature related, its winter over here atm, batteries come back up in warmer weather) encountered after 400 cycles (to 50% average) and 6500km.
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
Ok,
It seems I really don't have much of a choice after removing all the batteries and measuring the dimensions once again. Here they are:
option 1:
odyssey pc680 17 ah agm batteries @ $119 a piece * 8 = $960 total
The pc1200's (44ah) would be nice but they simply won't fit unless I rebuild the battery boxes completely. The pc680's are the exact same size of the 20ah guineng lead gel batteries that come with it. 20-25 mile range@35mph
option 2:
Panasonic nimh custom built pack from plastic 7.2 modules pulled from a used prius pack on ebay. This will only give me about 25ah and I already know two prius packs worth of cells simply won't fit on my scooter, then you have the custom voltage charging problem. For two used prius packs and 40-50 ah worth of energy depending on how many I can fit into the bike,
total $1200-$1400
option 3:
Keep my existing german built 10a charger for the original emax, get gary's 16 module bms system(since I understand this will allow you to use a standard lead acid charger with LiFep04 cells.) and the thundersky's from matt's source for $50 a cell.
$900 total
My daily commute to work is 17 miles one way usually at speeds between 30-40 mph. Option 1 would be the easiest to integrate and the best choice if my commute was even 5 miles less. I need to be able to have 50 percent charge remaining after I commute 17 miles, the only way I will be able to do this is with option 3. Although, I don't really have any real information on real life data on these thundersky, as long as 1 person has tried them and put over 1000 miles on them without problem, I don't feel I need to be worried about the batteries being as horrible as the guineng's.
Matt, How can I get them for US$1.10ah? I'd like to get started on this, this week If it's possible. If not I'll try and get the other guy to come down a bit on his.
Hi Bruce,
Im not sure if i can be much use to you getting cells.
Im in Western Australia, by the time we got the cells here and paid all duties can such, the price was around US$1.50/AH.
US$1.10/AH was the price at the factory, when we ordered alot of cells (i think 40'000AH? ill have to ask the organiser how big it was).
If you are located near Australia, you could probably join in on the next group buy.
Eric on the other thread is organising an american group buy i think:
http://visforvoltage.org/forum/4333-thundersky-w-monitoring-only
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
Bruce,
Actually, any CC-CV SLA charger works fine charging LiFePO4's as long as the voltage is correct. The e-max chargers which are about 59.5 volts work well charging a 16 cell setup.
The need for a BMS is a separate issue. The e-max chargers may need some minor modifications for them to work with this BMS - I'll report back when I have the BMS in and running.
By the way, the Gary's BMS is easily expandable to more than 16 cells by simply using additional boards (with the charger regulator circuit deleted) as slave boards.
I just put an order in for the TSLFP40's, cost me a little more than I wanted to spend. If I was 6 miles closer to work, I would have gone with the odyssey pc680's. They will be here later next week.
Here are the only options I know of for TS BMS:
http://evpower.com.au $500+
http://www.black-sheep.us $200 +
and the site mentioned above by PJD.
Did I miss something here?
Here's an update:
These batteries fit very easily into the ze-2000. I didn't have to mutilate anything at all. The only issue I had all night was grinding the existing wire terminals open slightly. The terminal bolts that come with these cells have a slightly larger diameter than the lead-gel batts. All cells came straight from hong kong showing 3.3 volts, even though I did think to order a few spares. I'm definitely going to need the cycle analyst and an affordable bms. I noticed that pick up seems improved, but the voltage drop under load is much more with these cells, you weren't kidding. Here's some shots:
I thought this was kind of interesting, considering some of the new bikes have these cells without a BMS.
I'm using my e-max sla charger to charge these since the voltage during charging reads between 56-59 volts. However, I did notice in the manual that came with these cells, Thundersky recommends a full charge of 4.2 volt per cell and a minimum of 2.5 volt. Does the community have a good, known working standard charge range for these LiFep04 cells?
Matt, I'm curious to know the voltage range of your aussy made BMS. It would also seem that my voltage drop is more than 5 volts under load. I don't have the cycle analyst yet but the charge meter shows full when not loaded then shows red under 25amp load. My float after charging this pack for just a few hours and making sure none of the cells exceeded 3.75 volts was like 55 volts, some of them 3.5, 3.4. I'm confused why slightly loading this pack causes the voltage to drop below 50 volts from 55. Maybe because I haven't fully charged the cells yet or don't have effective cell balancing?
Any thoughts?
Hi Bruce,
the voltage will sag by 0.2vpc per C of loading when the cells are fully charged and at room temperature.
more voltage sag will occur at lower SOC and temp.
higher temperatures result in a smaller sag.
sag isnt really linear, its sort of linear.
at 1C (40A), expect around 3vpc.
so 48v for 16cells.
at around 3C, you get 2.6vpc.
3.4 or 3.5vpc isnt a high enough charge voltage, those cells arent fully charged.
taking the cells to 4.2v wont damage them, though if done repetitively it will reduce cycle life.
i charge mine to 3.93vpc average. when current has fallen below 2A, they are 95% full.
my bms then discharges the cells to 3.67vpc (as the charger is maintaining a 55.1v float on the 3rd stage)
i only charge my cells to 95%.
dont do any load testing until uve charged all the cells, use a lab power supply if necessary.
out of curiosity, what bms are you using?
how are you measuring a 25A load?
at 25A the voltage should be around 49v for 16 cells (3.1vpc).
the reason OC voltage is 55.1v (3.35vpc) is because the OC voltage includes any remanant surface charge, and doesnt include voltage drop due to series internal resistance.
cheap cells such as thundersky's have a fairly high internal resistance, and so have poor power density.
for low power applications such as scooters (ie 3C or 120A or less) this isnt usually an issue.
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
I'm not currently using any BMS. So what i have to do is every couple hours, unplug the charger, drive it up and down the street once or twice to try and even the cell voltages back out a little. That seems to work. I haven't loaded the pack any more than a couple miles. During charging I've noticed the some of the cells fluctuate a little above 3.7 volts, while the others stay around 3.41 - 3.5. This is very difficult without a BMS.
Bruce
Have you tried to get the 16 cell BMS from TP packs .com. It says its cost is $89.
http://www.tppacks.com/products.asp?cat=26
I see it is not in stock but that sure seem like it would work for your batteries.
Eric Fisher
www.SiliconeBatteriesUSA.com
not sure if youve seen this thread;
http://visforvoltage.org/forum/4668-xm3500-bms-circuit
but it would probably work for your setup.
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
Update:
Correction, The emax charger I have shuts off when the pack voltage reaches 56.7 volts. I have the R. fechter bms board assembled and it works fine although my charger doesn't fully charge all of the cells. 7 of them are fully charged, the rest are like 3.4. Anyone here have something that will shut off when the pack reaches like 59 or 60 volts?
Matt, you have the same setup as me, what did that charger run you? What's the chargers shutoff voltage on yours? Even a little over 60 volts would be fine.
Hi Bruce,
this is the charger i currently use for my 15cells:
Dead Link: http://cgi.ebay.com.au/Lead-Acid-Battery-Charger-8Amp-48Vdc-230Vac-New_
W0QQitemZ120303284905QQihZ002QQcategoryZ50603QQtcZphotoQQcmdZViewItem
its max charge voltage is 56.7v aswell (holds it there until current falls below 1.5A or so)
I actually own a 10A version aswell that charges to a higher voltage (i cant remember how much higher as i use it rarely...its my backup that sits in my locker at work).
They dont have a 10A one on ebay atm, though you could email them to ask.
they also sell this charger:
Dead Link: http://cgi.ebay.com.au/Battery-Charger-20Amp-48Vdc-110V-220Vac-Auto-Switch_
W0QQitemZ120303968972QQihZ002QQcategoryZ30900QQtcZphotoQQcmdZViewItem
which gets up to 58.4v (3.65vpc). not sure what current it stops charging at though.
im not sure how the TS cells will deal with charging at 0.5C on every cycle though, though they are supposedly able to charge at 3C on occasion (20mins to full).
i once hit a cell with 160A while it was 90% full, voltage only rose to 3.6v in the 10 seconds or so i had it charging.
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
found it:
Dead link: http://cgi.ebay.com.au/Lead-Acid-Battery-Charger-10Amp-48Vdc-230Vac-New_
W0QQitemZ120283801377QQihZ002QQcategoryZ48618QQtcZphotoQQcmdZViewItemQQ_trksidZp1742.m153.l1262
so yeh the 54.8v final charge voltage *should* be enough to fully recharge your pack.
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
I currently have 16 cells. 3.2 volts nominal per cell and the community recommended charge voltage for these is 3.7 volts fully charged. That is what my bms keeps the charge at. 3.7 * 16 = 59.2. So the 54.8 volts for 16 cells won't cut it. For 15 it will probably do just fine.
The problem I'm having with 15 cells hooked up to a 16 cell bms is that the last cell in series (+) gets cooked. The rest of the cells show about 3.7 volts like they should. If I hook up 15 to the bms and don't hook up a cell to that last pin (+) on the bms, the charger won't even kick on. So I have to skip the 2nd to last pin on the bms and hook the 15th cell up to to the 16th cell pin header on the bms and leave the 15th empty.
My blue plastic case type e-max chargers have a CC charge voltage of about 59.5 volts and work fine with my Rich-and-Gary BMS boards. The current level at which the charger shuts off is also adjustable, so I have been able to adjust them for automatic shutting off when charging is complete.
I will get a report together on the whole mess soon.
sorry, that should have been 58.4v, not 54.8.
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
I have the same e-max charger. But the charger shuts down when the pack reaches 56.7 volts. Every 48 volt charger I've tested does the same thing. Why is your's different, unless you modded it? I've adjusted the blue pot inside but the shutoff voltage is still 56.7 volts. Hmmm...
update:
I've got the bms built now and all the cells balanced. If the cells have never been charged before, as mine were, you have to use a power supply to charge them to 3.7 volts. After you have charged all the lagging cells, the emax charger brings all of the cells up to 59 volts or so.
You can see that I used an old p4 atx power supply male wire harness and some 18-22 gauge butt splices to connect the bms wires to the board. I used a female sata hd connector for the charger hookup and a power cable extension to connect them together. These worked wonderfully.
Noted aggravations:
- 18 gauge ring terminals for the battery nuts for these cells are not widely available. I had to use 16 gauge ring terminals with 18 gauge wire and just double up the ends of the wire so they would fit snug.
- Time involved with building board and understanding the proper polarity of parts on this board. I ended up having to re-solder the led's on after I assumed the square on the board was always the anode. This is not always the case as I have been told. From what I understand this board will no longer be available through gary and that he will be selling a new universally compatible board that has an auto shutoff feature.
- Extra power supply used one time to charge new cells all the way up.
Conclusion:
Was it worth having batteries shipped all the way from hong kong and having to build a board from small parts and constantly babysit and measure voltages and make sure the cells weren't overcharging?
Hell yeah...
It's true that choosing the enersys batteries and my batt-eq's solution would have taken 1/5th of the time this all took. But I wouldn't have gained the following:
- 60 lb lighter bike.
- max speed for longer period of time.
- Voltage on these cells after coasting seems to recover faster.
- Definitely more range or useable energy in this pack.
Tonite I took it for a 20 mile trip. Since I don't have any kind of ah meter on the bike I'll give you voltages. Start of 20 mile trip - all cells register 3.64 volts. End of 20 mile trip - all cells register 3.27 volts. The cells after the trip were barely luke warm. I'm impressed so far.
I'll be riding it back in forth to work next week 17 miles each way to work and report back. I'm trying to get the guy down the street to re-finish the fiberglass all black with the bat sign
Hi Bruce,
congrats, its good to hear your bike is up and running :)
i forget, are you able to charge at work?
if you intend to do 34 miles on a charge, i highly recommend getting an AH counter (cyccle analyst is the best ive used so far) before your first trip.
the voltage falls off a cliff as you pass 37AH . itd be a shame to have to push your bike home on the first day.
i average around 1.2AH/mile on my commutes, but my average speed is 40mph, so hopefully you will use less on your setup at lower speed.
out of curiosity, what is your new top speed, and what was your old top speed?
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
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