Blueb0ttle2's Lithium Noob Project Thread

[blueb0ttle2]

After almost a year of mulling over and reading about the subject, I am prepared to get a lithium pack. And I am open to suggestions. But first, some back story...
I got a Tres Terra Europa electric bike, which runs on 36 volts and (I presume from the brushed Heinzmann motor's specs) will take up to 30 A. It originally had Lithium, but the guy I bought it from converted it to lead. The thing weighs a ton, and I don't like the arrangement very much. (He had two 12V 12AH of the batteries in the old battery compartment, and a third in a pouch on the back rack), and I thought such a worthy steed deserved lithium.
I want specs like these:
-Fits within in a space of 4" wide, 4.5" tall, 13" long (about 101mm W,114mm H, 330mm L)
- ~36 volts
-15+ AH. I can live with 10AH but won't like it
-LiFePO4! I am scared out of my wits of DIY LiPo. I know I'm chicken, but please humor me :lol: .
After some research I came up with three realistic possibilities (so far) for someone with a limited budget that just wants to buy a pack or two and not sacrifice quality...

1) Get a custom pack from cell_man
Pros: Excellent reputation, A123 cells with awesome specs, lightweight, reasonable price, appears to be easy to communicate with.
Cons: Cannot be repaired easily by user.
Price: Not the cheapest there is, but appears to be a fair deal.

2) Get a ready-made pack from Headway HQ or build your own headway pack
Pros: blistering specs, very easy to repair (due to screw terminals)
Cons: fair but expensive, 12 cells may not quite fit in the limited space I have due to large size.

3) Custom Ping!
Pros: Good reputation, Very, Very reasonable price, workable specs.
Cons: Recent rumors of failures, might not be easy to communicate or give special instructions. Pouch cells are not as sturdy. Cannot be easily repaired by user.
Price: As stated earlier, can't be beat without serious quality sacrifice.

I am leaning towards cell_man right now, but the ease of repair that headway packs offer is a very tempting prospect. I hear no one has had trouble with cell_man's product though.
Cheers.

Once again, I am willing to take suggestions, so long as they are not for LiPo or fission power 8)

 

[neptronix]

First choice would be the A123 pack.. cell_man builds them by hand and can build them to fit certain shapes. But you're right about maintaining it. I have yet to hear of anyone needing to maintain their pack however. And the BMS is supposed to be pretty good too.

Headways are great for the ability to replace cells like that, but they will use more space than the other 2 options.
I don't know much about headway HQ yet.

pings will take the smallest amount of space and they are pretty good, if your amp draw is under 30amps, they'll work. They'll just be saggier than the above two options.

 

[blueb0ttle2]

I agree, the flexibility of the A123 cell packs will make life easier.
There used to be some debate about Headway Headquarter's reputation, but they now appear to be solid. One of the main folks there is on this forum (I think he goes by JimmieD) and participates in the headway pack builder's thread.
I'll remeasure the space that's available to me before pestering any of the professional pack builders.
I still have doubts about the 1000+ cycle lifespan being true, but the light weight, size, and C rate of a good lithium cell is almost enough to make up for the added cost.

 

[neptronix]

I don't doubt the 1000 cycle lifespan too much, however said cycle lifes are usually measured at 1C or below.
How many people run their packs at or below 1C?

 

[blueb0ttle2]

lol. yeah. I'll probably be running at 2C.

 

[dogman dan]

Not continuously, but you will pull 2c spikes. Another good reason to go with 15 ah.

FWIW, I now have about 600 cycles on my first ping, which was definitely a 1c cell in the v1 packs. It's been ridden three years at an average of 1c, but at times has seen a whole LOT more in spikes. The first 250 cycles were done with a watt hog brushed motor an 35 amp controller, on 20 ah pack. Climbing a 1000 foot tall hill daily, it pulled 25 amps some for sure.

So if you get say, 800 cycles, it can still be years and years of riding. That first ping paid for itself two years ago, so now every ride costs only the dime for electricity.

 

[blueb0ttle2]

One of the things I am worrying about is communicating with the pack builder. If I am laying down $350+ I want to receive what I asked for in the mail. Is Ping easy to speak to in English? Judging by the website, Ping Battery has staff that can. But I just want to make sure. Who has experience with getting custom packs from ping, and what did they make of it?
cell_man is British (But based in China) and Headway HQ is here stateside, so I am not too worried about asking them questions.

 

[blueb0ttle2]

I'm now somewhat against pings, since I'd have to build a hard case for them for protection. I think my space is too limited for that.
I think I ought to post pics of the frame and its battery compartment so you folks see what I'm working with.
According to my calculations, I could cram 108 A123 cells in my compartment, which should give me about 20Ah. Not sure if I can afford it :lol: Similarly, I think 12 headways will fit comfortably in there too.

 

[blueb0ttle2]

Wait a minute.... Should a typical Li pack have 11 or 12 cells per "36V" string? 11 gives 35.75, and 12 gives 39. Would a typical controller handle the 44 v of a fully charged 12 cell pack? Somehow I suspect that 11 cells would be best, given that I am running a Heinzmann motor.

 

[blueb0ttle2]

Just had a thought. 12 cells is fine, since a fully charged "36 volt" lead-acid battery pack would be 43.5 volts, which is pretty close to the ~44 volts that a fully-charged 12 Li cell string would have. 12 cells appears to be standard anyway. The other advantage is more usable range, obviously, and more speed from the git-go. Have I said anything totally wrong there?
So, when I have a spare moment I'll discuss the possibilities with cell_man and possible Headway HQ. As good as Pings are, I am biased towards cylindrical metal cells for their sturdiness.
As I said, I'll post a pic of the battery space in my frame soon.
I'm still dancing around in theory land, before I set down any cash.
So my possibilities do far...
-108 A123 cell pack (19.8 AH) Which would be really really nice. The price for that will probably be above $500 though
-12 cell 16AH Headway pack. I think 12 cells might actually fit in my space! Still gotta ask though.

I desire to run with minimal pedaling between 15 and 20 MPH for at least 10 miles (20+ would be better). Would I need a 20+AH pack, or would 12AH do, especially since lithium has a longer usable range than the lead I'm used to (Peukert effect, etc.)?

 

[blueb0ttle2]

Some pictures of the bicycle and it's ready-made battery compartment. I am going to replace the front brake with a mechanical disc brake. The original suspension seat-post has been replaced. The plastic battery compartment cover has been removed for clarity.

 

[blueb0ttle2]

Funny how quickly one's mind changes! I now favor pings. Since I have heard good things about them (and they have a decent price), I will contact them first and ask if they can make a pack that meets my criteria. If not, I'll contact cell_man.
I'll make a case for the battery out of thick plastic to protect it.
Just got the disc brake
whoa. That's what I call a brake.

 

[blueb0ttle2]

I sent the following email to ping...

Subject: Custom 36 Volt Battery Pack Inquiry

To whom it may concern,
I am an American electric bicycle user and member of the endless-sphere forum who is interested in ordering a custom-made pack from your company. You have such a good reputation and reasonable prices that I thought I would consult your company first to see if you can meet my battery needs.
I need a 36 volt pack that fits within these dimensions...
-330mm length
-110mm width
-110mm height
-I would like to have 20AH capacity, but if you are not able to fit such a large pack in that space anything down to 15AH would suit my needs.
If you can build such a pack I would like to have a cost estimate including shipping to the zip code ----- in the USA.
Thank you very much for your time,
Xavier

I misspelled battery in the original subject heading, but I think that should get the point across

 

[Pure]

Sorry but I'm going to have to say it. That battery compartment is screaming for LiPo to be shoved in there.

I've been away from the site for some time and regarded lipo in the same manner that you do. I recenty upgraded to a 60 volt LiFePO4 and now after doing a lot of research and reading see that lipo is no where near as scary as it used to be. I'm actually kicking myself. For what I paid for this current pack I could have 100 volts of lipo and kickass chargers to boot. I'm so convinced that I'm actually going to shelve the lifepo4 and convert to lipo.

 

[blueb0ttle2]

This will be the first time I ever use Lithium in an ev. I don't trust my ability to build a pack yet, least of all with lipo. As I said in my first post: please humor me
Perhaps after some more experience I'll build one. I've only been dabbling with ebikes for a year, after all.

 

[Pure]

Indeed and fair nuff. I def respect your decision. I just think you should (if u havn't already) spend a good bit of time reading all the current threads on lipo before dismissing it. Either way I wish you luck.

 

[wesnewell]

Yep, I'd put 20ah of 12s 15c zippys in there in a heartbeat, with a little room to spare. More power and more Wh than non-lipo options. What kind of bike is that anyway.

 

[blueb0ttle2]

It's a Tres Terra Europa. With a Heinzman brushed motor. It originally had Lithium in it, but its previous owner replaced it with lead. When I test rode it it felt like it was doing ~32kph. It ought to do well enough with a ping. I just want it to be a low maintanence commuter bike.
The motor is labeled as a 24V 235W motor with 30A max. I am certain that that's original motor. The controller says 17A, which I assume is its continuous rating. I'll slap a speedometer on there when I get the battery.

 

[blueb0ttle2]

Just got a response from ping. He says that they can only fit a 15ah pack in my space. Would that suit my requirements (20 miles minimum pedaling)? I need a fairly quick response. Thanks.

 

[NickF23]

speed is pretty important when trying to guestimate range. Assuming 20mph top speed and your not going up a 20 mile hill then the answer is yes, that's enough capacity

 

[blueb0ttle2]

Thanks man!

 

[blueb0ttle2]

Alright my dear friends,
I am awaiting my ping battery's arrival. He said it would take a couple of weeks. So my pack is going to be 15Ah, which ought to fill the bill.

 

[blueb0ttle2]

I received my battery from ping. It looks good. I just want to double check something, though...
I hook up the balance cables and then charge. Right?

 

[Ian]

I received my battery from ping. It looks good. I just want to double check something, though...
I hook up the balance cables and then charge. Right?

yeah hook up the balance connectors, then connect to charger, then power on charger. think the info is on pings website too. I got a iacocca evg so similar kind frame to yours, with a ping 24v 20ah in the bay and 24v 20ah on a rear pannier. Same weight as the original 24v 10ah SLA and 5 or 6 times the range. Mine has a 9c on the back, that has worked out good too. Had the pings a year now and they're just great, I only needed 1.5c and wanted at least 3 or 4 years pretty heavy use, so made sense for my application. Stick a CA on the bike I would if you haven't already.

 

[blueb0ttle2]

Thanks man. I have been tempted to get a cycle analyst for some time. I might slap one on there when I recover from the ping purchase :lol: