BatterySpace 37V/8AH Lipoly (pack cuts out at 20A sustained)

Reid, if in your shoes, and not into a DIY pack, I'd ask Mike for a quote on a 3p10s pack of emoli's. Looks like it'd be about $500 for 37V 9AH. The 2000 cycle longevity ought make up the price difference easily. You already have a charger and there'd be no need for a BS BMS. :)

http://bigerc.com/index.php?cPath=21_26_33


Another option: get quote on one of Mike's "specially priced" a123 packs. Might require a different charger, or you could use your 10-cell charger with an 11-series a123 pack.

Or you could do similar to what jondoh did, and use three 28 volt 3ah V28 packs in parallel for about $130 each (or ~$100 on ebay), with another $50 for the charger:
http://www.toolbarn.com/product/milwaukee/48-11-2830/
http://www.toolbarn.com/product/milwaukee/48-59-2818/

Money was the only reason I didn't choose the emoli's or a123's in the first place. I wanted a BIG lithium pack, and the only way I could afford that was lithium cobalt 18650s.

Might as well do it right the first time since your energy requirements are more modest...
 
xyster said:
Reid, if in your shoes, and not into a DIY pack, I'd ask Mike for a quote on a 3p10s pack of emoli's. Looks like it'd be about $500 for 37V 9AH. The 2000 cycle longevity ought make up the price difference easily. You already have a charger and there'd be no need for a BS BMS. :)

http://bigerc.com/index.php?cPath=21_26_33


Another option: get quote on one of Mike's "specially priced" a123 packs. Might require a different charger, or you could use your 10-cell charger with an 11-series a123 pack.

Or you could do similar to what jondoh did, and use three 28 volt 3ah V28 packs in parallel for about $130 each (or ~$100 on ebay), with another $50 for the charger:
http://www.toolbarn.com/product/milwaukee/48-11-2830/
http://www.toolbarn.com/product/milwaukee/48-59-2818/

Money was the only reason I didn't choose the emoli's or a123's in the first place. I wanted a BIG lithium pack, and the only way I could afford that was lithium cobalt 18650s.

Might as well do it right the first time since your energy requirements are more modest...
Click to expand...
You quoting a 2000 cycle life is just as bad as the rest of so called specs . Try testing TRUE cycle life.At 80% discharges there is not much out there that will get that kind of cycle life with even .2 C discharge rates other rhan the Kokams that the Rc guys cycled out at 2 C rates for 300 cycles from the batteries rated at .2 C Discharge rates for 1400 cycles. IMO Kokams are the only Batteries that do show the best value for cycle life.But please finish your testing as futher proof.
 
when i added 9# of sla, from 27 to 36, i was worried about the extra weight. well i couldn't even feel it.(location is everything, the wrong spot will be awful)
now i'm planning 96# for emergengy use. i bet i feel THAT! LOL Well maybe not. it will still weigh less(202#) than even an emax(265).
Harley's weigh 650!
at 202 i'll still be light.
xyster needed lithium because sla really was too heavy for that much range.
maybe reid just wants the cool factor, he sure doesn't need it. 27-39# of sla will do just fine.
 
Matt, I've had 3 nine pound bricks on the bike in the past.
Had two on a seatpost rack, which eventually snapped without the least warning, locking the rear wheel.
Not cool. The batteries lost oomph relatively quickly, but they did have low internal resistance.

Only the lipoly cells seem to offer nearly such low internal resistance.
Only the lipoly cells have a relatively-long tested longevity ((I know what to truly expect))
Only the lipoly cells allow a super-simple series arangement of ten pure cells.
The BS pack of lipoly is not of Kokam quality, no, but it's cheaper than just about anything you fellows have just suggested.
28V drill packs are not wanted.
It's not the "cool factor" so much as the clean, neat, light, ready-power that the tight lipoly pack can and does offer.
The bike handles and feels better with a five pound battery than it did with thirty pounds.

We make our decisions based on personal prefs. For me, strings of cells in S and major P are not appealing.

I can change my mind any time. But, I suppose one year from now I'll have a whole different battery agenda. Won't we all?
Well, not Matt---his tailored scooter is just fine with capable, cost-effective lead.

I will roll on one way or another. Abrasive as he may be,
Randy's point is sound. Let's see the life of the new cells in service.
I expect good things, sure. But claims are cheap and generally not attuned to real-life results.
 
From the BatterySpace forum.

Anyone in the mood for more criticism?
I surely am not. With a few spelling corrections by me:


powerizer said:
I discussed with our engineer. Possibilities are:
(1) PCM got damaged because sparking occurred in your pack --- this did happen to us and damaged one channel on IC

(2) One cell may be bad.

I believe the best way is you send back your pack with charger, we can double check for you. Otherwise, we never know what happen.

If we send you another one, it may be damaged again.

We can use computerized battery analyzer to see what is real capacity , and see what is real problem




Please be advised nobody has enough experience on polymer Li-Ion pack yet. We may stop selling the battery pack unless they use our e-bike kit to reduce trouble.

{Reid notes: to clarify, the pack was originally designed with the thought to sell it with their hub motor kit as an upgrade. The standardly supplied trailer hitch connector proves this so--that's what their hub motor kit uses}

You may try NiMH battery pack . It is much more reliable than Lipo pack. We can refund your money if you like.

( As we indicated on website, we don't want sell the battery pack to end users , we don't provide any warranty in this stage )

I have asked our customer service send a email to ask you to send back for inspection. We will cover shipping cost for you.
Click to expand...

I can't complain too much, now can I?
Still think I should bail?
And if I do quit, and they in turn quit this whole project in dismay,

where does that leave us all? With lead and emoli drill packs, mostly.
Well, at least we know lead is a sure thing--no surprises there.
 
i almost bought dewalt packs, but i decided to wait until all my sla are dead. in the process i discovered how robust sla are, i ran 1 down to 2v from 12, no problems. Now for me sla is the standard to beat.

single li cells in series is wimpy

3 or 4 a123 in parallel is beefy.

a123, by all reports except mega amp deafscooter look great

once all my sla die i'll consider all, but the primary reason i'd pick non-sla is cycle life(lower cost per ride) i think i can do 30-48¢ with sla, so i'll try that combo 1st i suspect
(3-18ah @$30ea +boost sla) (that's 180-280 four mile grocery trips over 2-3 years) $30-45 per year is going to be near impossible to beat. Even a disappointing 90-140 trips at $60-90/year would be fair for the low cash outlay.

Good luck reid! I'll respect whatever u decide, it's your ride :D
 
Ewww :oops:

Nah SLA are only good for holding the door open imho.

I have a twin pack of 13Ah NIMH cells that are half the weight let me go 4 to 5 times as far and are performing better now than when i first got them nearly a year ago.

leads dead!

Just my NIMH worth!

ha ha

Knoxie
 
Sorry to hear about the batteries Reid. Hope it gets resolved.

Knoxie quote:
leads dead!
Click to expand...

I like Lead. "1000 mile club now." Limit amps to 20 and flat terrain and use soneil charger.
 
there is a learning curve for each type.

i like nicad as they have lasted 7-10 years in my drills. but the price is way up.

reid
extra weight goes in the triangle not the rear rack.
 
knoxie said:
leads dead!
Click to expand...

Lead still has its place as an excellent standby battery for occasional, heavy use (like occasional e-biking), or regular light-duty use (like in a continuously recharging car battery application).

Over at the Old V I recall calculating that for applications that drain the battery more than twice per week, the cost of lead over 5 years becomes higher than the cost of much better, lighter, nickel or lithium batteries.
 
I agree with Knoxie, leads dead baby :D

Reid and Xyster,

Bare in mind that emoli are a pretty new and unknown chemistry, according to Cadex(on the 'battery university' site) maganese oxide cells do suffer from some kind of calender aging, though, unlike lithium cobalt, resistance doesn't increase as at that the same time. As a second source, people with the ezee lithium packs do report capicity loss with time. Perhaps emoli 2000 cycle figure presumes your cycles are in the first year or two, or perhaps emoli chemistry/design has overcome such issues.

From the sounds of it lithium phosphate batteries are a different story. Both valence, a123 claim 2000 cycles to 80% dod and no specific calender aging. There's an interesting story on EV world about the killacycle electric motorbike, it uses 880 a123 cells and runs them at 100 celcius. They've been doing this for 18 months with no dead cells yet. Apparently a123 are rated at 1000 cycles for a 5% capacity loss at C!0 discharge rate (in otherwords 23 amps per cell). Pretty amazing stuff, shame there so pricey still.
 
I'd fix the pack myself. Split it apart and test all the cells for capacity. Toss the bad one(s) and replace as needed.
 
reid
whatever u do, u want to avoid warranty down time.
when a nicad shorts, the pack works fine, down 1.2v.
same with sla, -2v.
not sure on nimh.
but your lithim can catch fire! so u need 2 packs, 1 to ride and 1 to send back during the debugging which might be months or years.
after warranty u pick the best cells from the 2 packs to keep going.
 
Matt Gruber said:
reid
whatever u do, u want to avoid warranty down time.
when a nicad shorts, the pack works fine, down 1.2v.
same with sla, -2v.
not sure on nimh.
but your lithim can catch fire! so u need 2 packs, 1 to ride and 1 to send back during the debugging which might be months or years.
after warranty u pick the best cells from the 2 packs to keep going.
Click to expand...

I have RC lipos from Kokam, Thunderpower, GWS, Apogee, HE, and a few no names. Over 30 of them. No brand is immune to having a bad cell here and there, and replacing a cell is actually easier than changing a cell inside a big NiMH pack.

Use a balancing charger and a low voltage alarm and your lipos will live a long and happy life. I have cells dated 2004 that are still working strong.
 
OK reid
how about
1. send it back and have them fix it.
2. instead of $50 for wires, buy 1 or 2 spare cells.
3. if the repaired pack is good, forget future repairs, fix and wire it yourself.
 
Lowell said:
Matt Gruber said:
reid
whatever u do, u want to avoid warranty down time.
when a nicad shorts, the pack works fine, down 1.2v.
same with sla, -2v.
not sure on nimh.
but your lithim can catch fire! so u need 2 packs, 1 to ride and 1 to send back during the debugging which might be months or years.
after warranty u pick the best cells from the 2 packs to keep going.
Click to expand...

I have RC lipos from Kokam, Thunderpower, GWS, Apogee, HE, and a few no names. Over 30 of them. No brand is immune to having a bad cell here and there, and replacing a cell is actually easier than changing a cell inside a big NiMH pack.

Use a balancing charger and a low voltage alarm and your lipos will live a long and happy life. I have cells dated 2004 that are still working strong.
Click to expand...
as long as you discharge them only to 80% staying below the rated discharge rate.Which is usually less than a .2 C discharge rate to 80% discharge..If you KNOW all your cells are balanced on the charge cycle you can monitor the sum voltage for your own manual cut off when the voltage starts to sag below 30 volts per pack until a good BMS is on the market.Single 12ah Kokam cells in series would make great ebike packs for building blocks.Note less internal resistance on larger cells.=less pukert effect at higher discharge rates+ eaiser cell replacement with bolt on wire tabs..= less heat per cell!
 
Single 12ah Kokam cells in series would make great ebike packs for building blocks.Note less internal resistance on larger cells.
Click to expand...
Yes, and 20Ah in pouches would be yet more lovely.

At this time the largest easily available high-drain rate (5C) cell other than Kokam, is the Wanma 8Ah.

There are lots of 4000mAh cells on the market for the RC guys, but not many 8000's.

I found an 11000---but it is only 1C rated.

This is just an interim period--if ebikes were a market pressure larger 5C+ cells would be here now, and not just those of Kokam.

Main point: I most want a series-only lipo pack; that would be most ideal;
and 20AH 5C or greater, would be so sweet for an urban bike, a ten pound battery which I would be discharging at not more than 1C rate; or at one fifth of its permissible discharge rate. And so it should give especially fine cycle life.

Lug-terminal cells in plastic boxes would be so much more rugged yet;
and most easy to swap out--but at that cost of much greater bulk.

LA batteries used to be similarly modular cells.
 
Reid Welch said:
Single 12ah Kokam cells in series would make great ebike packs for building blocks.Note less internal resistance on larger cells.
Click to expand...
Yes, and 20Ah in pouches would be yet more lovely.

At this time the largest easily available high-drain rate (5C) cell other than Kokam, is the Wanma 8Ah.

There are lots of 4000mAh cells on the market for the RC guys, but not many 8000's.

I found an 11000---but it is only 1C rated.

This is just an interim period--if ebikes were a market pressure larger 5C+ cells would be here now, and not just those of Kokam.

Main point: I most want a series-only lipo pack; that would be most ideal;
and 20AH 5C or greater, would be so sweet for an urban bike, a ten pound battery which I would be discharging at not more than 1C rate; or at one fifth of its permissible discharge rate. And so it should give especially fine cycle life.

Lug-terminal cells in plastic boxes would be so much more rugged yet;
and most easy to swap out--but at that cost of much greater bulk.

LA batteries used to be similarly modular cells.
Click to expand...
Yes IF ! there was a volume ebike market that needed lithiums and IF ! people would pay the price.A couple of BIG IFs.If you can get these Kokams cycle life may be realistic for 800 cycles ?

http://www.kokam.com/english/product/battery_main.html
 

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Wow Reid! You are exhibiting incredible flexibility in your experience with the BS Lipo pack.. sh!t happens. If these guys can't work with you on sorting-out a replacement pack -it would not bode well for their experience/expertise in this field.

Bending over backwards is one thing (you seem to have pulled 360 degrees), paying full pop to become a full-fledged beta tester is all-together another!

Arduosity, perseverance, sweet reward.
May the later come sooner.


Fingers crossed, -S
 
Hi Steve and all,

I hear you, Paul. I'll bite my tongue because I don't know the full story.

The pack will be sent back on Monday.
I'll consult with BS after they've looked it over.

I'll decide then whether to bail from the deal.

If the pack is =nearly right=, it seems a shame to quit and maybe cause their project (price is reasonable, right) to get shelved.

So I may not bail.

Even hobbled this pack is intriguing.
The concept is good although there's a devil in the details.

A year from now this'll all be a quaint history
---drill packs, defective beta lipo packs,

all this will pass away and we will smile (grimmace, more like it)
in recall of this primitive period not unlike the blacksmith's era of the single cylinder automobile.

Velectris lipos
http://www.velectris.com/catalog/batterie-lipo-p-50.html
 
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http://tinyurl.com/24r66n
 

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