New to Elec Bikes and did a dumb thing

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elchucko13

New Member
Jul 26, 2011
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Guess
Don't beat me up to hard...........I'm a slow learner. I didn't investigate the subject. I thought hey the "more the better" when looking at bike kits. OK I knew I'd have to add a battery but I went ahead and bought a 48v/1000w kit. Now I find out these batteries are not cheap! Where can I find the "cheapest" battery pack for the kit? Thanks
 

SoSauty

New Member
Feb 4, 2011
147
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Bako, CA
I don't know cheap. Sealed lead acid SLA batts will let you down, they're so poor as to turn you off to e-bikes. PING is your greatest value and also safest. You'll be happier to have a batt that'll last you 5-10 years. It'll pay you back long run 3 to 6 cents a charge!

http://http://http://www.pingbattery.com/servlet/the-48V-LiFePO4-Battery-Packs/Categories

You can buy a $475 Walmart e-bike, put a $350. batt on it and have a good rig. You can't buy a $2000 world class e-bike kit, put an SLA batt with it and not think much of it after 20 rides.

Best to ya'. (If you're willing to learn and craft your own batt box, Lipo @ HobbyKing works but inherently can be dangerous for begginners; more compact, mighty, and will last at least of couple of years.
 
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kevyleven007

Active Member
Sep 25, 2008
1,217
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texas
ok just kidding.You said CHEAPEST.Heres what you do.Get yourself 4 12v12ah sla batteries off of e bay.25-30 bucks each.wire them up in series.This will give you a 48v pack that will put out enough amps at the lowest price.You kit may have included a charger.If it did your all set.You did say cheapest and not lightest or best.This will give you maybe a 10 mile range.
 

xenodius

New Member
May 23, 2012
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Spokane, WA
In the long run, LiFePO4 is the cheapest/most reasonable solution, but it's pretty spendy at first. I'm pretty sold on Headway cells because they have comparatively good discharge ratings, and you can pack them together real tight if you stagger them. (use 2-sided foam tape for cushion.) If you do it yourself they aren't terribly expensive, but ping are still probably the cheapest and least work, and I've heard they're doing better on their BMS/chargers lately.

Just remember than LiFePO4 will last a LONG time. From what I've read, they're especially good at handling partial cycles and good-old-fashioned time, but either way will give you lots and lots of cycles. LiPo degrade with age, but LiFePO4's age-degredation is almost zero.
 

paul

Well-Known Member
Dec 23, 2007
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Kalamazoo, MI
i would really look at getting a lifepo4 battery and not the lipo. big reason is safety also take into consider that lipo only good for greater then 300 cycles and a lifepo is 1500 to 2000
 

xenodius

New Member
May 23, 2012
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Spokane, WA
For lipo it's worse than just cycle life. Storing a lipo at room temp, roughly full charge for one year results in a 20% capacity loss. If it's at 100F, then it's about 35% loss. But worse than that, as it loses life the cell resistance increases! So it's a cumulative effect... But storing at low temperatures and at about 40% charge help a lot. Even so, that's not accounting for any use at all!

Why bother with all that mess when you can get a LiFePO4 pack that will last many times longer, work below freezing and over 100F, never explode or catch fire, provide virtually flat output except when deep-cycling (dont do that!) and has incredibly high energy density given it's durability? (220wh/l for Lifepo4 vs 300wh/L for LiPo) After a year, it'll have better density than the lipo pack.

Beyond that, LiPo is expensive! Not to be confused with inexpensive li-ion. (4.2v vs 3.7v)
 

kevyleven007

Active Member
Sep 25, 2008
1,217
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texas
LiFePO4 is heavier.and thats the only drawback.I would go with headway cells if you want to go that way.The prismatic cell are way heavy
 

kevyleven007

Active Member
Sep 25, 2008
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texas
Do those LiFePO4 batteries come with a waranty?If the did it probably wouldnt cover road abuse.Mine only lasted 1 year but my bike got knocked over a few times.my lipo in alluminum box is at 3.5 yrs and starting to die.time to start saving up,stuff costs a fortune
 
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n3glv

New Member
Jun 14, 2013
37
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Pittsburgh
ok just kidding.You said CHEAPEST.Heres what you do.Get yourself 4 12v12ah sla batteries off of e bay.25-30 bucks each.wire them up in series.This will give you a 48v pack that will put out enough amps at the lowest price.You kit may have included a charger.If it did your all set.You did say cheapest and not lightest or best.This will give you maybe a 10 mile range.
I bought 40ah @ 24v from china, 5A charger and 45A BMS.
LiFEpo4, the same seller sells a 48v@20ah for same price. With bms and
charger. $479 shipped to usa.
If you went SLA I would get 4 from SEARS, they have a warranty.
12v 10ah x4 would be about $120 and you would get at least 1 set replaced
for free!
Mind that you can expect 300 recharges from SLA and at 2000 charges that
the LiFEpo4 will be @ 80%
Do the math, the LiFEpo4 is cheaper and wider voltages etc.
 

Catfisher

Member
Apr 10, 2010
134
1
18
Heart of Illinois
I don't want to hijack this thread, but perhaps expand it a little.

One thing that has kept me from going electric has been the expected lifespan of rechargeable batteries. The initial investment is so high I would need to believe that with proper care and charging the batteries can last long enough to become economical.

If you live in a climate where you might ride 6 months a year and have a lifestyle of occasional or sporadic riding how long could LiFEpo4 batteries last? I've been concerned that the batteries will crap out or quit taking a charge more from lack of use than from overuse.

I might only use 100 charge cycles in a year at the max and the batteries may sit under maintenance for 5 - 6 months through late fall and winter.

How does this affect LiFEpo4 batteries and how many years of use would you expect to get with this scenario?

.flg.
 

16v4nrbrgr

Active Member
Mar 17, 2012
1,728
4
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North Bay
I'm still a fan of SLA battereies, and manage to gaet about 200-300 cycles from mine. If you can find me a 60V LiFePO4 pack that can provide 100A continuous, that doesn't cost $1500, I'll switch.

I've got some LiPO batteries to try out but I want to be prepared for the worst! lol
 

kevyleven007

Active Member
Sep 25, 2008
1,217
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texas
Yep you cant beat SLA's for a cheap thrill. Just make sure you have an extra charger on hand!
 
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middriveebike

New Member
Sep 25, 2013
10
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Toronto, ON, Canada
If you go for SLA battery, get AGM instead of gel.
AGM is better for deep cycle and better for constant charging and discharging.
Get 10Ah AGM batteries for the most reasonable range, price.
Since these batteries are heavy, you better find a local store who sell them instead of having them shipped.
Also, spend some money to purchase a good charger. It extends your battery life.
 

n3glv

New Member
Jun 14, 2013
37
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0
Pittsburgh
If you go for SLA battery, get AGM instead of gel.
AGM is better for deep cycle and better for constant charging and discharging.
Get 10Ah AGM batteries for the most reasonable range, price.
Since these batteries are heavy, you better find a local store who sell them instead of having them shipped.
Also, spend some money to purchase a good charger. It extends your battery life.
Sigh......
AGM is Absorbed Glass Matt.
They are NO WHERE NEAR AS ABLE TO PUT OUT HIGH CURRENTS AS SLA.
Full stop!
THEY SUCK FOR HIGH DISCHARGE. PERIOD!
My '450w' currie ezip has a 35A pwm (factory)
A set of 10Ah 12v x 2 to get 24v Sealed Lead Acid can't put out more than
about 18A, if I used AGM I doubdt I would get 5A
Understand that a "10Ah battery" is 10 amps across TWENTY HOURS. Ie:1/2amp for 20hrs. Any higher discharge and capacity is nearly logrythmically <sp> reduced.
High current discharge spanks lead acid badly.
Single 10Ah pack on my bike = 5.8miles
Ran two in parallel and got 19mi and saw major increase in torque since it
then could put out the full 35A on hills..
Of course at that point I had a 94lb bike......hrrm
It's now LiFEp04 40ah@24v, single 18.8lb pack vs two at 16lbs each.
I geto an honest 45+miles even in Pittsburgh Hills and the math based on
my 9.5-10A at full throttle on the flat is that it can do 15-17mph for four hours!

AGM are NOT for HIGH DISCHARGE like an ebike. These people selling them
as direct replacement for SLA are WRONG / FRAUD / SALESMEN

Do some more research, you'll see what I mean.

While we're on the subject of Lead Acid and chargers...
Anything more than one tenth of capacity for charge (called 1/10C) is agressive. Most ebike chargers are around 1.8Amps into a 10Ah pack..
Expect about THREE HUNDRED RECHARGES before the pack is nearly shot.
(60% range)
LiFEp04 is rated at 80% at TWO THOUSAND recharges, they really are the best deal in town when you consider replacement costs.
 

n3glv

New Member
Jun 14, 2013
37
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Pittsburgh
Agreed, that is why I bought the ezip trailz from walmart.com
it was pre-built and running (5.8mi range was unexpectedly low)
Doubled the pack for $140, ouch, and ran wire to parallel them, that got me to 19mi, but batts were nearly kicked in one summer.