What chemistry do you use? (Ver. 2)

Chem? (Pick all that apply.)

  • Lead (Flooded, AGM, Gel)

    Votes: 76 18.4%
  • NiCD

    Votes: 14 3.4%
  • NiMH

    Votes: 28 6.8%
  • Inert Lithium (LiFe, Manganese, etc.)

    Votes: 226 54.7%
  • Volatile Lithium (Polymer, Cobalt)

    Votes: 139 33.7%

  • Total voters
    413

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Joined
Dec 9, 2007
Messages
2,799
Location
The Roxbury
So, what's in your cells?

I've got 48V and 20Ah of LiFePO4 ready for the S-Go's eventual (hopefully soon) comeback, and 72V and 5Ah of lead in a backpack for the PackCycle.

Continued from: http://endless-sphere.com/forums/viewtopic.php?f=5&t=1762&st=0&sk=t&sd=a&start=0

This poll reflects current utilization, so previous poll participants are requested to update here.

You can update this poll when you change/update/blow-up your packs.

Please comment on unique features your pack may include.

Any suggestions welcome. :D
 
Well done, this way not only do I get to upgrade my response from last year I can also indicate I'm using both SLA and LiPO4. The SLA's are in my scooters, they are all 24 volts and two of them take 12/12 and the third, my workhorse, takes 12/20.

On a side note, my workhorse, an older GS Moon 3 wheeler, was getting weak. Repeated trips to the dock or hauling yard trash to the curb were killing the batteries much too quickly. Since I had lent my old dependable battery charger to a neighbor last year and since he returned it in a condition less than ideal I had to toss it and replaced it with a multi tasking Black and Decker model from Wally World. The new charger, even though it was only about $75.00, does lots of things and one of them is to desulfate the battery. As of this moment I have one of the 12/20 batteries on the bench going through it's 24 hour cycle of desulfation. In 48 hours I fully expect the old girl to be running strong once again.

The other scooters, my cheap Chinese e scooters, are running strong and are ideal for lifting over the gunnel and putting on the boat when we go on a trip. Being cheapo scooters they have had their problems but have all been quickly resolved. (with a lot of help from the members of Endless Sphere) The rust situation was fixed by sanding the rusting chrome and painting it with a spray bomb metalflake black and now they look better than new. When I upgraded the bikes batteries to LiPO4 I wound up with four B&B 12/12's that were only eight months old and still very strong so I took the others out of the scooters and replaced them with the B&B and I think I can tell a difference. Perhaps the best part is a friend of mine has a 36 volt scooter he uses around the community, mostly as a toy. Since he let it sit for several months in an uncharged state he has about destroyed his batteries so I'm going to replace his old batteries with the ones that came out of my e scooters. He'll pay 50% of the cost of new B&B's and we will both be winners. (then I'll desulfate his old batteries and see what happens)

Mike
 
^^^Him smart.^^^

:mrgreen:
 
Staying with lead myself. Don't want to pay $400 for new upgraded batts and chargers.
 
I started off with SLA when starting the electric bicycle citing then current shipping hassles, price, my relative lack of experience(When I'm inexperienced, I usually intend to "go cheap" while I learn the essentials just so I don't happen to gloss over some essential basic and acquire something that I later learn isn't ideally suited for my needs), and an opportunity to gain appreciation for clearly more effective chemistries. I also thought it as an effective stop-gap until the shipping fiasco subsided(as SLAs only go for, what, 100-200 cycles at 2C and 80% DOD?).

Luckily, though, I found an auction hosted by a member of ES in the states so that instantly short-circuited the shipping hassles rationale and I happened to have to money at the time for the price I bidded which was on the low side at the market prices at the time, if the specs were to be believed. So I abandoned my SLAs at about 40 cycles, and now I keep them as back-up batteries and for current and future 12V accessories on my bike(Currently, lighting, future... a stereo-system? :lol: ) and as counter-weights in my panniers for the LiFePO4. It seems 1 12V "12AH"(more like 7) effectively counterbalances a 48V 10AH. I'm contemplating about putting them on a scooter I'm thinking about eventually getting.

Unfortunately, it seems this pack has a weak cell that limits the pack's capacity to 7AH and I'm not trying to resolve this with the seller as he was advertising a "10AH battery". He hasn't responded yet. :x
 
Built my first ebike about 6 weeks ago. Was considering lead-acid because I like cheap, at least until I determine if I should spend more, and what I should spend it on.

I saw this thread http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=4908&start=240 about the LiMn batteries available only here in Canada at Canadian Tire, which is everywhere here. Over the counter warranty exchange with no questions asked almost for one year is very good for batteries like this. They work pretty well (and MUCH better with BMS removed), price is good: $110 plus taxes for 120 watt hours rated; good for 100-120 WH real. (18.5v nominal, 21v max, rated 6 AH, real 5-6 AH.)

So now I've spent $1000 plus for 1000+ WH of batteries and I'm quite happy with them, especially now that I've reduced them to banded cells without power sucking, temperamental, heavy and bulky BMSs and cases.

Initially used these on my recumbent http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=5749 but my current project is kids mountain bike http://www.endless-sphere.com/forums/viewtopic.php?f=6&t=6224 . LOTS of fun :)


I now feel/realize that batteries and chemistry are VERY important for ebike, and may be most important factor; for range and speed/torque. They are the most expensive "single" part of my ebike.

Inert Lithium, FTW.
 
Deafscooter still use AGM and SLA battery that handle lot amps on discharger to feeding the monster motor
doped fluid inside boiled acid cells give more more three time better than standard Agm or Sla Battery packs


Craig
Deafscooter
 
Lipo for me, also safe the way I use them, with outdoor charging no more dangerous than a tank of fuel strapped to it, i.e a motorcycle, light and powerful :D
 
Started out with 36V Foxpower Lifepo4 then added 12V SLA to make it 48V. Then got hold of a defunct Dewalt so 12V of another Lithium to replace the SLAs till four of the ten Dewalts died a couple weeks later then back to the Lifepo4 SLA combo again. Another 48V pack of Lifepo4 on the way. Currently building Dewalt packs for the next e-bike and recycled NiCad packs for a trailer on the running bike so I will have more range.

Update another 48V of LifePo4 will be in the bike soon it's on the kitchen table for now. The SLAs are no longer being used. I have 102 Dewalt cells for a couple packs not sure if it will be 48V or 60V. Lots of NiCads waiting to be packed up also.

36V lifepo4 off 48V on the bike and on the road again. The right half is in the bag left is out. Rats nest charge wires will be cleaned up soon enough. Good thing I put them in enclosures as one bounced off of the bike and got drug down the road. Stopped picked it up hung it back in it's place, plugged the Andersons back in and off I went. Not damage at all. Pic of bike soon to come.

48vpairsm.jpg


Well the Dewalt a123 26650 cells at 66V now have several hundred cycles, 2 years worth of abuse on them and they are still werqing fine. No more low C rate batts for me ever.

56vdewaltpack1.jpg


Just got hold of some a123 20 ah cells for the next build expect these to be even better. Now to find a good way to connect and contain these things.

a12320ah.jpg
 
Lipo

24S 2P 10Ah
25C continuous
100.8V fully charged
88.8V nominal
72V LVC

I charge with 8 power supplies tied in series to make 100.8V
I balance with different methods every 5th time or so
I have a 25 channel BMS but dont keep it on the bike
Cells stay in balance to the tune of about 100mV worst case

Zippy R 25C 6S 5000mah (8 of them)
Each pair in series are tied together at the balance tap level
Pairs are strung together with 8gauge wire

I draw 180A at launch
Generally about 60A cont.
Have a couple hundred cycles on them

Pack lasts about half a day of reasonable off road riding

-methods
 
I use all LiPo batteries 22.2V 4000mAh 15C and 7.4V 4000mAh 15C
My first pack excists of 5 parallel packs which are configured out of 22.2 and 3 7.4 in serie
I just ordered some new 22.2V because of the space. instead of 3 x 7.4 which also is 22.2

Here is a photo of the chage section. It consists of 3 LiPo balancers which can charge my LiPo's in 1 hour!!
IMAG0078.jpg
 
Look, this year it's LiFePo4 for various reasons.
Here's my mount, at the moment *until tomorrow*

it is not secured, not yet, with an invisible strapping system just devised.


That battery will not go anywhere but stay on the bike, upside down, dropped from a cliff.

LiFePo4, pop tart packs, for now:

http://i244.photobucket.com/albums/gg28/Reid_Welch/Early%20PING/P1090327.jpg
 
I have three different setups at the moment:

1. 24 V SLA (18 Ah), 0.45 Ah/mile (top speed about 16 mph, flat no pedaling)
2. 36 V SLA (6.5 Ah) ) 0.5 Ah/mile (top speed about 24 mph, flat no pedaling)
3. 48V 20Ah ping LIFEPO4 (not measured precisely yet, but >30 mph)

For my commute and my setup, I have WAY too much capacity with (1)&(3). I can charge at work and have an 8.6 mile ride on a mostly flat bike path with exactly 7 stops for road crossings. I pedal with the bike contributing about 100W.

What have I learned? 24 mph is too fast for me to feel comfortable on my bike path (minuteman trail in boston). 6-8 Ah is perfect for my situation, and anything more just adds weight. At night, I need a better way to see the road without blinding other SLOWER bikers.

spkt
 
Oh Man, MrKang, thank you, but MOST ALL ebike newbies have no idea of what happens when/if defective lipo goes up in self-fueled flame hotter than an oxygen-acetylene torch.

Just a short, just a bad charger, just a tiny error in assmebling, and Mr. Newbie has just lost his home or his life or both.

LiPo for those who KWYADAWYADI, and manganese or ferrite lithium for we others.
Cheeful advocation of liPo, without warnings, is a cheerful invitation for blithe, incompetents, to die =because you did not tell them bettter= how vital it is that the battery, not a single cell, ever short.

500 million at least, of miniature lipos are in "safe" service: with big corporate names behind them. There are tons of no-name chargers and defective, bare cells. Build cheap. Good luck, probably nothing will happen to the home brewer of budget, obsolete but so-light and wonderful old LiPo explosion tarts.

My leanings; I am not a battery eggspert. :lol:
 
Sounds like the why to go, also sound complcated, I want plug and play, you know a daily driver, I do not want to fart around chargers and batteries every evening
 
I've been using lithium ion cells (cobalt) for 7 years. Most of that time I've been running without protection, ie no BMS. I tried using BMS's for a couple years, several years ago, but the units I tried were marginal, most failed, some burned up and one nearly caused a fire.

I ride daily, year round in Chicago in all weather.

I had one fire early on where I lost 2 cells and damaged another pair when slush built up on an improperly sealed connector and eventually penetrated it and shorted out a couple wires. This was on a pack of Thundersky 10 ah cells where there were wires for charging every cell individually. I had a fuse on the battery for the main discharge tap, but incorrectly assumed the small gauge charging wires would function as fuses themselves.

I stopped using the Thundersky connectors and got rid of the separate charging wires, simplifying my pack construction to only have the two main power wires entering each pack. I also changed the design of my pack cases. Originally I made enclosures from thin aluminum sheet for good cooling. I glued in strips of closed cell foam to keep the cells and wiring out of contact with the conductive case but felt nervous about it. I switched to making boxes out of coroplast. It seems cheesier but has worked well enough. Coroplast offers decent protection against vibration and impact although it does retain a little more heat. I've managed the heat issue through careful matching of my batteries, controllers, motors and loads.

I switched to anderson power pole 45 amp connectors. Those aren't waterproof so I had to take care to make sure all connections are in protected places where they don't get wet. For the batteries that meant putting the connectors inside the battery cases instead of outside them which is a little more awkward but has worked out well enough.

Without the separate charging wires I had to stop using the Thundersky chargers which I didn't much like anyway and I switched to using variable DC power supplies which I still use to this day. The downside was no more automatic balancing. For a while I carefully checked each cells voltage with a multimeter before and after every charge. For day to day use where I would charge more frequently but only up to about 4.1 volts per cell and terminate discharge before hitting 3.65 volts.

I switched to larger capacity packs, 20+ ah to minimize heating and to allow for extended all day weekend rides. Before those I manually balance the packs while doing a full charge using a multimeter, light bulbs with alligator clips and a kitchen timer. I kept a log of manual balancing and always knew the weakest cell in my packs. For a long while I had a mini pocket multimeter mounted on my handlebars but eventually switched to a self powered mini panel digital voltmeter attached to the weakest cell so I would know when to ease up and when to stop.

While this has worked for me, it hasn't been 100% foolproof. At times I've cut corners due to the tedium or inconvenience of frequent manual monitoring of each cell with a multimeter. Over the years I've had a few incidents and mishaps.

I'm currently running packs built from 18650 liion cells. They are 3 years old. Within a couple years I'll rewire them as a massive 12 volt pack and keep using them for a couple more years to power a big trailer mounted sound system. The liions currently powering the sound system are now 5 years old and in a couple more years will likely be unfit for even that and I'll have to look into recycling/disposal.

While I've managed to get by for a long time on the cheap I am looking forward to the advances in batteries and electronics. A couple years ago I added using a WattsUp meter and switched from power poles to bullet style connectors used by RC modelers. I've just ordered an iCharger 208B and the cell-log8 which I expect will make it easier than ever to take good care of my batteries.

I' m not sure what batteries I'll try next. I like the idea of moving to a safer chemistry with a more gentle aging curve but my guess is energy density and cost factors may still override that.
 
Same Lead from '08 here. Cheap robust safe ,and um cheap. Checked prices today on ebay- $70 for 420Wh shipped.. 10 pack of 7ah 6v's. Yeah yeah heavy bulky saggy and peukurt, I know.

Am playing around with a lipo booster pack to get a feel for it though.. will go life when the time comes.

Still curious what pixie dust DS put in his sla electrolyte.. then mebbe I can do it too and be a DS wannabe.
 
Hi ,
New guy here.
I chose NiCad batteries 36v 8 ah when I bought my E-zee conversion kit from ebikes.ca,because, after reading all I could about batteries I felt that if a cell went bad in my pack I could troubleshoot it and replace it myself. I was in the market to build the best rocksolid commuter I could for my daily 8 mile one way ride, and my more infrequent 32 mile commutes. I have put about 800 miles on the bike so far in various weather, and been very happy with it so far,although
Never more pleased than today,with wind gusts to 35 ,and light,intermittent snow/icepellets .
 
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