Recommend me a battery please

[berge06]

Hi

I picked up a 1000w 48v kit based e-bike, for free a while back.

Can someone recommend me a good affordable battery. I will use the bike mostly for short trips.

 

[wesnewell]

What do you call short and at what speed do you want to go?

 

[berge06]

Hi

I consider 10-15kms short and speed in the 40-50km/h range if possible, its a steel mtb with 26" wheels.


I want something faster than my 250w 24 bike on 24v sla.

 

[wesnewell]

2 of these in series (or any other 10ah 12s rc lipo pack) will get ~18 km @ ~45 kph.
http://www.hobbyking.com/hobbyking/store/__56845__Multistar_High_Capacity_6S_10000mAh_Multi_Rotor_Lipo_Pack.html

 

[Keith Pegg]

I like the http://calibike.com/ battery I have the 20 AH one and have used for a year now. Low cost and triangle bag is great.

Keith

 

[berge06]

thank you guys.

Do you think a 6s lipo would be enough for my 24v bike?

6s is 22,2V wouldn't this trigger a low voltage cutout?

 

[wesnewell]

thank you guys.

Do you think a 6s lipo would be enough for my 24v bike?

6s is 22,2V wouldn't this trigger a low voltage cutout?

A 6s pack charges to 25.2V. Typical LVC for a 24V controller will be ~21V. A 6s rc lipo pack is perfect for that at 3.5V per cell. At most, you could use a 7s pack, but a 21V LVC would be a little too low for a 7s pack unless you want to squeeze every last drop from it.

 

[cycleops612]

On balance, I like lifepo4 pouch cell batteries. last forever & no fuss. much simpler and repairable.

https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20161005060136&SearchText=48v+lifepo4+battery

in normal form, to achieve the hugely long lives they boast, 1C discharge and 1.5c bursts should be fine - so 10ah is 480/720w for 1h or 40mins. its 6kg.

else, 15ah should be fine with the full 1kw in bursts and a steady 720w, and should weigh 7-8kg, and have more range than your stated needs.

a bet each way is ping

http://www.pingbattery.com/servlet/the-13/48V-10AH-V2.5-LiFePO4/Detail

they dont say it, but they use smaller 5ah pouch cells in parallel, to achieve higher c-rates. ie, they use 32 3.2v 5ah pouch cells in a pack, instead of the usual 16x 10ah cells.
other companies also do similar. no links am afraid, but i have seen them.

its only 5kg and can do 1000w peak sustained they claim, and they are reputable.

myself i would spend the premium they charge on a larger 15ah noname battery, and live with the extra ~2kg of weight.

on paper, lifepo4 suffer by comparison because very important failings in lipo and limn are glossed over, namely, they weaken drastically (voltage drop) during the ride, and at least 20% and maybe 30% of claimed capacity is pure nonsense on an ebike - it is unusable for riding. When ordering limn packs, you really should allow 50% more than specs claim is sufficient.

a 10 ah 1C limn claims 480w output for an hour, and therefore is ok for a 480w motor. BS. For 5 mins maybe after a charge. Then it steadily weakens, until 80% empty, and shuts down.

 

[berge06]

Thanks guys!

I guess we will see what I buy

 

[cycleops612]

fyi, i mentioned ping use smaller 5ah cells in parallel to improve C-rates.

so do these (probably cheaper) guys

https://www.aliexpress.com/store/product/36V-15AH-LiFePO4-Lithium-Battery-with-BMS-5A-Fast-Charger-Electric-Bicycle-Battery-For-Electric-Scooter/513166_1695017027.html

this one is rated 2c (1kw) continuous discharge and 4c burst rates.

even the 10ah one should do you, but 15ah is nicer.

 

[tomjasz]

I've got a generic 48V10Ah LiFe setup which can output peaks of 1300W that I've tested on my 48V1000W kit with good results. They're easy to manage, much safer and more durable. For 5+ years people have been clamoring on about how LiFe is dead... yet the good cells continue to set world records so...

So how does one sort the generic packs and resellers. I need to replace a couple of 36V packs and was thinking I'd try an LiFe, just because.
I don't need high Ah since it''' go on a 15A BBS01. 11Ah 22P packs gets the wife 30-40 miles.

Next build will be a trike and weight won't matter, actually it'll be an advantage. FWD Delta, old man trike.
Thanks!
TD

 

[motomech]

For Lipo, 9S is what to use for a 36 V controller w/ a LVC of 31 V. The cell value @ LVC is around 3.60 V.
I'm assembling a 12S/10,400 mAh Lipo frame pack that costs $160 to put together. It's for a Cute based budget build that I will doc. later.
The pack is based on 6 of these;
http://www.hobbyking.com/hobbyking/store/__56840__Multistar_High_Capacity_4S_5200mAh_Multi_Rotor_Lipo_Pack.html
and will fit in one of these little over the frame saddle bag;


I'll post more details when it's done.

 

[cycleops612]

I've got a generic 48V10Ah LiFe setup which can output peaks of 1300W that I've tested on my 48V1000W kit with good results. They're easy to manage, much safer and more durable. For 5+ years people have been clamoring on about how LiFe is dead... yet the good cells continue to set world records so...

So how does one sort the generic packs and resellers. I need to replace a couple of 36V packs and was thinking I'd try an LiFe, just because.
I don't need high Ah since it''' go on a 15A BBS01. 11Ah 22P packs gets the wife 30-40 miles.

Next build will be a trike and weight won't matter, actually it'll be an advantage. FWD Delta, old man trike.
Thanks!
TD

well, NB, u wont have to replace lifepo4s - 2k charges vs ~600 IF u laboriously fuss over them

22p - yikes - really? does bms have any effect (or even the required number of balancing ports?) on balancing parallel cells - i have long wondered?

lifepo4 simply requires 12 cells of appropriate size for 36v - THAT i can trust to balance properly.

OTH,

3.7v lipo pouch cells have appeal in that the cells can be large like lifepo4 pouch cells. They come in factory packs with bms.

Its also a cost and hassle thing. A choice between the most expensive item on the bike lasting 2 years or 7 years of daily full charges.
see my recent post re a 4c 10ah 48v lifepo4 - 2000w peak, 36v should be 1440w.

Its instructive that limn e.g. abilities are vastly overstated with their battery cowboy era specs (capacity & actual sustained voltage) whereas lifepo4 tend to be understated.

a 10 cell 36v lifepo4 e.g. is briefly 37v after charge, lifepo4 is 12x 3.3v (~sustained til empty) = 39.6v, or 14% higher = more watts - 10 amp 36v=396wh. Most pouches have a little more capacity than rated also.

 

[d8veh]

Don't waste your time with LiFePO4. It's much too heavy compared with alternatives. This is today's technology battery. That's a 52v BBSHD with 300wH battery. You can carry a spare in your pocket if you want to go more than 15 -20 miles:

 

[motomech]

For many of us "weight and volume" are what's important.

 

[cycleops612]

For Lipo, 9S is what to use for a 36 V controller w/ a LVC of 31 V. The cell value @ LVC is around 3.60 V.
I'm assembling a 12S/10,400 mAh Lipo frame pack that costs $160 to put together. It's for a Cute based budget build that I will doc. later.
The pack is based on 6 of these;
http://www.hobbyking.com/hobbyking/store/__56840__Multistar_High_Capacity_4S_5200mAh_Multi_Rotor_Lipo_Pack.html
and will fit in one of these little over the frame saddle bag;


I'll post more details when it's done.

Thanks for that.

Its a scary issue for we noobs - changing battery chemistry on an undocumented controller.

a noob buys even an expensive bike, and discovers they cut it very fine on the battery to compete in price & cos its the conventional wisdom.

if he lives with it, he still needs new after a few years. he decides on a better chemistry, but has to comply with an existing controller, probably optimised for limn.

who knows what their lo volt cutoff is (lvc) is on their bikes controller, and precise discharge characteristics and their interpretation?

Is there some wisdom i am missing. are controllers configurable by users?

its as if the pak makers ought offer a matching controller? then u get the fraught wiring connections matchup thing.

as it happens, the lvc of limn and lifepo4 are similar, but thats just luck. If the controllers lvc is set too low for protecting the battery, the bms cuts it off first.

But, as i say, its just just luck.

As u say, for lipo, an upgrade requires a ~custom battery pack (conventional wisdom says 10x3.7v cells =~36v, not 9x) to comply with most 36v controllers.

Is there no other soldering free option such as adjustments or programming? I doubt i am the only one a bit mystified.

 

[cycleops612]

Don't waste your time with LiFePO4. It's much too heavy compared with alternatives. This is today's technology battery. That's a 52v BBSHD with 300wH battery. You can carry a spare in your pocket if you want to go more than 15 -20 miles:

Curious how most here are from nth america. Most americans seem huge - 100kg (220lb ~)+++. most bikes discussed seem heavy cruisers etc weiging 40kg +, & street legal power that is 3x eu rules, which is most modern countries.

There is no point to high c-rates if u r limited to a ~200-250w motor (I am sure there are many ~undetectable cheats up to 350-450w, but legal status is rightly important to many (an accident resuting in litigation - yew)). May as well get; constant, cheap/durable, simple - ie, lifepo4. Anyhoo, lifepo4 can do 4c , which is plenty.

Yet ~5kg weight suddenly becomes a big deal when it comes to the most important, time consuming and expensive component of all - the battery.

Those who place no importance on range seem disproportionately vocal. I think most on the planet want a balance of range and power, rather than standing quarter mile times alone.

And anyway, folks with lipo tend to be old hands with expertise (no hassle lipo pouch paks with a bms would tempt me too, on a light sporty bike), its the noobs getting sucked in by limn that i mainly have a problem with.

There is no "best" (including my views). Its entirely subject to needs, means and circumstances.

 

[tomjasz]

Don't waste your time with LiFePO4. It's much too heavy compared with alternatives. This is today's technology battery. That's a 52v BBSHD with 300wH battery. You can carry a spare in your pocket if you want to go more than 15 -20 miles:

I'm on the same path. I have a 20Ah and use it for long days or for my grocery hauler, but for general running about a 14s3p is a great stealth pack. Perfect for the BBSHD.

Will finish a 36V soon.

 

[tomjasz]

There is no "best" (including my views). Its entirely subject to needs, means and circumstances.

Spot on!

I wish I could use Lipo comfortably year round, but it's just to cold for outdoor charging. Until I have a fire cabinet it's never happen in my house. I have all the gear at ready and one of these summers I'll have at it. For now the charger and power supply is used to test and charge cells for recycled packs. Summer use.

 

[tomjasz]

I like 18650 shrink wrap packs from http://www.unitpackpower.com
That will make a shape ala d8veh
I have several. Also sold by others without revealing the source.

 

[cycleops612]

There is no "best" (including my views). Its entirely subject to needs, means and circumstances.

Spot on!

I wish I could use Lipo comfortably year round, but it's just to cold for outdoor charging. Until I have a fire cabinet it's never happen in my house. I have all the gear at ready and one of these summers I'll have at it. For now the charger and power supply is used to test and charge cells for recycled packs. Summer use.

A good example. Its a matter that wouldnt enter our heads here in oz.

I may be wrong in fact, but in principle, sporadic/intermittent use of an ebike may influence my choice.

To not use it for a few months and not risk damage.

I get the impression lifepo4 are far better at sitting idle and limn are not good. Others may be good at remembering to charge to some storage schedule, personally I am not.

I am not alone here in having multi bikes/packs & other distractions. You cant ride them all at once, or life may call you away from home at times.

PS, have u considered an electric blanket on bike/battery while charging.

 

[LewTwo]

....PS, have u considered an electric blanket on bike/battery while charging.

Or maybe a basalt (several layers) blanket

P.S.
Totally off subject ... Someone should start making basalt fabric cases for Samsung's phones.

 

[berge06]

Thanks for sharing your experience and knowledge.

 

[berge06]

Would 48v 10ah enough for my needs?

https://www.aliexpress.com/item/sil...32483773700.html?spm=2114.01010208.8.7.pBVKiv

I can see this is a 18650 based battery. I have messed around with 18650s before and built some small packs out of old laptop batteries, but that is a different story.

The bike might be used in some rather steep hills would still 10ah be enough. The kit is pulling 15-20 A.

 

[motomech]

For many of us "weight and volume" are what's important.

As long as you factor them along with other specs and judge them according to your needs, bravo to you. The problem I'm lamenting is the misuse/overrating of high energy cells in favor of pocket-sized batteries.

The problem I'm lamenting is the misuse/overrating of high energy cells in favor of pocket-sized batteries.

Oh, that sure clears things up.