what battery to use ? 36v - 48v for heavy bike at 1200W

C

cargobiker

1 mW
Joined
Sep 14, 2013
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10
Hi all. (sorry for my bad english)
Im gonna rebuild my cargobike to be electric driven.
I searched for 2 days for info and now i found this forum.

Its a trike that weighs 60Kg + 50Kg load and a 90kg driver :) So ruffly 200kg (440lb)
I would like a minimum range of 25Km (15Miles). (25miles should make me verry happy if possible).

I bought a Brushless Hub Motor on 26" rim thats gonna fit just perfectly :). Ill sum up all the tech data i got from the seller:
-Motor 900W at 36V / 1200W at 48V.
-Speed controller unit with 25 Amp current limit.
-Can be powered by any 36V or 48V battery pack with min 30A discharging current.
what does this mean?

What battery should i use?
36V ? 48V ?
Im not looking for reaching high speeds but keep in mind the 400+ lb.
iv been lookin at lifepo4 48v 20Ah 400Dollar battery ... but is there a better option (maybe a little cheaper to)?
What does this battery (above) mean for my cargobike range and so.

whats the relation between the Ah value and the continues disgarge A ???
 
AH = Ampere / hour = Capacity
A = Ampere = Instant discharge

So increasing the number of AH increase proportionally A.

30A discharge for a 36V setup = 1080W
30A discharge for a 48V setup = 1440W

Did the seller gave you the motor speed at 36V and 48V? If so, we can determine the speed and consumption of your bike. And deduct from here the required battery voltage and capacity.
 
It depends on what you want and how much you actually intend to use the bike.

The most cost effective for e-bike applications are Sony Konion V3 Li-Ion cells.
They have a very good power to weight ratio, capacity to weight ratio, excellent cycle life and drift-free: no bms needed.

I recommend you not to fool yourself into thinking you can get good quality battery packs from China. I would make sure to get quality cells that will last you a long time.
The battery pack is the most expensive part of the bike and there are huge differences in quality and I would not go with an outdated technology like LiFePo4.
 
The 48v battery will make your bike go faster with more torque, but it will be more inefficient when you go slowly. If you only go slow, the 36v battery might be better, but you should push the amps up a bit by adding some solder to the shunt in the controller. We need to know the RPM of the motor to give exact guidance.
 
Your inquiry led you to here, the best of forums to get answers. Welcome to ES! I suggest you use this site as a repository of already answered questions. Meaning a judicious use of built in or google search will be the most expeditious means of getting answers. And there will be a divergence of opinion, which if weighed with good judgement, will help with your understanding of battery tech. Hint: its not just voltage, but underlying cell chemistries and their stated operational ranges that will be important in the long run. Make a well informed decision BEFORE you buy and avoid failure. And yes, get a battery that will last for your particular use.
 
25mph engine top speed acording to seller.
Ok no china battery then. what type then (ill look up the sony batterys after typing this).

So 15Ah should give a steady 15A for 1 hour ? is this right ?
 
The top speed depend on your battery voltage.

Is it 25mph top speed at 36V or 48V?

And how do you plan to travel? Do you travel mainly at low speed, with a lot of stop and starts? Or do you have long straight road? Do you have hills?

If you travel slow, with hills, lot of stops and starts, get a 36V battery. But you'll run slower. Probably 20mph

If you want to go a bit faster, get a 48V. It'll be a little bit less efficient on start and slopes, but it'll allow you to run faster and with better torque.


Tell us what's your journey and what speed you want to travel and we should be able to help you.


Ps: lifepo4 could still be a good battery as it has incredible lifespan over any other chemistry. They are heavier but will last longer over time.
 
Well, the cycle life of the LiFePo would be interesting, if their capacity to weight ratio would be more interesting.
Even after 500 full cycles (!) The Konion V3 cells still have more than 90% capacity. I don't know anyone who will do 500 full (!) cycles in under 3-4 years.
How many cycles will it take until the capacity to weight ratio of any cell will beat the Konions?
Next question: At the point of time, when that maybe happpens - if it happens at all - (some time 2018-2020) do you think, that you wouldn't want a new battery pack with a much better capacity to weight ratio all together?
 
When I say lifespan I also mean the shelf/calendar life. Currently Konion calendar life remains unknown.

And of course, if cargobiker has the money, a 48V20AH of konion V3 cells would be better than Lifepo4. But you can probably tell him if he can get this for 400USD as you're selling it.
 
Low speeds and a hill on the 2 times a day ride of 6miles to school and back.
A few times a week a ride down town 10 miles including lots of stops.
And maybe a summer ride to work 22 miles to and back.

400dollar was for china lifepo4 48v20ah...
found one from france for 800dollar ... :/

*edit*

So 36V 20ah lifepo4 china 300dollar should be better for me than the 400 48v one ?
Or should i buy quality lifepo4 ? how would i know ?
Or newer konion battery (what is that? BionX Lithium or li-Mn ???)
 
I think both 36V and 48V would work for you. 48V would be a little bit less efficient but would give you the additional range you may need for summer.

If you don't mind speed you can get a 36V battery, you need at least 20AH. I'd get 25-30AH to be on the safe side.

If you have money, you can get the new Konion V3 cell schwibsi is selling. I'll let him give you a quote, but I think it's going to be closer to 800USD than 400USD.

Benefit of these cells over Lifepo4 are the weight and volumetric density. So a 48V20AH pack would weight around 5,5kg for the Konion V3 and 10kg for Lifepo4. It'll also be smaller.

But as you have a cargo bike, my guess is few more kg is not that important. And you can get them much cheaper with lifepo4. Their calendar life and cycle life have been proven.
 
Comparing voltages and watthours of different batteries is similar to comparing cars.

You can get a 500 horse power american muscle car for a fraction of the priceof a 911 turbo. If you only compare power or torque you won't get a clear picure.
I said it on the other thread aswell: Saving 1kg on a bike makes a world of difference and when you look at the amount of money it takes to reduce a bike's weight by one kg, using a better battery technology is a real bargain.
I've upgraded quite a few people from LiFePos to Li-Ion Konion cells. A friend of mine got a 13s9p 48V 20Ah pack from me for his trike and he saved over 2kg of weight, which he's very happy with.

I don't ship outside of Europe, as DHL won't accept battery packs of intercontinental shipping.
Also, I don't make any money off the packs I make for the people here. I only charge the material and do the work for free. Some people are nice enough to tip me a little, when they're happy with the pack, but I don't require it.
 
You should not calculate the battery in Ah, but in Wh because that is the real capacity the packs have.
BionX uses cells very similar to Sony's Konions.

35km is not that long a stretch. You shouldn't need 1kWh. 650-750Wh should be plenty. But you can always parallel two packs and turn them into a larger one with more Ah in case you realize that you went to small.

You should keep the maximum speed your motor/battery combination can do as close as possible to your target cruising speed so the motor will be in it's most efficient area most of the time. This will also help you keep the heat in check when you go up hills.
So, check out the motor speed and the circumference of your wheel incl. the tyres and then ask yourself how fast you want to go realistically. I would suggest getting a slower wind and upping the voltage. Anything below 60V is fine and not life threatning.
 
im going for lifeop 36V 30ah china one then , if i need to buy 2 to get a sony kion lifespan so be it , ill probly pay bout the same if not cheaper , maybe prices drop as new technology comes ?

Or do you recomend one?
shipping to europe and max total price with charger and sending +- 500Dollar (not bms since it came with engine)
Remember.
engine 900watt @ 36V,
the bms has a 25A limit and a min 30A discharging current battery needed ??? i dont get this advice :) .

oh please recommend one i cant pick one afraid to pick wrong one :)

*edit*
Ok ping battery 36v30ah = 800dollar :)
and china /hong kong ones about 500 (my budget) ...
 
OMG. 36V and 30Ah. That's much more than you'll ever need.
Check the weight on such a pack first and think about, what you're going to do WHEN (not if) you find out, that the capacity they sold you is not even close to what you got.
Where are you located by the way? There must be somebody in your area, who can make you a quality pack.
I buy a lot of, if not almost all, of my ebike stuff from China, but transistors and battery cells are the two areas, where you just have to make sure that you get good quality and not some cheap copies that will lie, when it comes to capacity, cycle life and internal resistance.

At the end of the day, you have to know, what you're doing. I've given more than my share of fair warning.
 
ok find me a good battery that ships to belgium whith charger for a max of 500 550 dollar.
First time i need to buy something on internet cause its not locally possible and im going nuts . (since most e-bike shops here are way to expencive due to a booming market and the legal limit is 250watt :/ )
thank you all for the help so far ill see you tomorrow i need sleep :) on ebay you find everything and nothing at same time...
*edit* Forgot to mention charger usa 110v is useless to me :p
 
999zip999 said:
Look at the sunthing-28 battery on ebay.
Click to expand...
I think he changed his name to cycling-2013http://www.ebay.com/sch/cycling-201...me=STRK:MEWAX:IT&rt=nc&_trksid=p2047675.l2562

Biggest concern s the hills you need to climb. How steep are they and how long. At 400lbs you might need a differant motor or a small wheel ot climb those hills.

As other said a few kgs don't seem like much, but they sure add up. Cut back on what ever you can and it will help.

A cheap GOOD battery is hard to find, but no problem if money is no problem. You might need to get the extra AH for a cheap one so it's all up to you.

Dan
 
cwah said:
how do you plan to travel? Do you travel mainly at low speed, with a lot of stop and starts? Or do you have long straight road? Do you have hills?

If you travel slow, with hills, lot of stops and starts, get a 36V battery. But you'll run slower. Probably 20mph

If you want to go a bit faster, get a 48V. It'll be a little bit less efficient on start and slopes, but it'll allow you to run faster and with better torque.
Click to expand...
48V is less efficient ? in what way ? explain please ...
You also say 48V has more torque ... So U can speed up quicker but it uses a little more battery power ? Or do you mean at qruising speed ?

From what iv read, More V = More speed (+Tiny bit more torque)
More A : More Torque (+Tiny bit more speed)

So at 36V 20A its slower than at 48V 20A Right? but they have the same amount of torque (little more on 48V? or a good bit more due to the higher watt?).
But a 48V 30A Is the same speed (iti bit more) than 48V 20A ?

Does 36V use less Amp then a 48V for same qruising speed? (I think not) Or does a why should 36V be better ? I Dont get it :) HELP

Sorry i say again im completely new to E-biking. Dont shoot me. meanwhile i go look for more info .
 
DAND214 said:
999zip999 said:
Look at the sunthing-28 battery on ebay.
Click to expand...
I think he changed his name to cycling-2013http://www.ebay.com/sch/cycling-201...me=STRK:MEWAX:IT&rt=nc&_trksid=p2047675.l2562

Biggest concern s the hills you need to climb. How steep are they and how long. At 400lbs you might need a differant motor or a small wheel ot climb those hills.

As other said a few kgs don't seem like much, but they sure add up. Cut back on what ever you can and it will help.

A cheap GOOD battery is hard to find, but no problem if money is no problem. You might need to get the extra AH for a cheap one so it's all up to you.

Dan
Click to expand...
Money is a problem :)
Better a cheap Big 48V 25+ Ah (minding the used cells and the continues Disgarge Amps a little) Or same priced quality product with (far?) less power ? ?

A "factory" E-Set is available from the cargo bike manufacturer.
Lithium Ion Poly Battery 24 Volt / 10 Ah
15Kmh HELPINGengine (9.3Mph) - Torque 25,6 Nm
And all this Great power for 1 333 Dollar .......... Yeah i know... that main reason i try self build.

Hoping for Decent power on a Lower price tag :)
 
d8veh said:
The 48v battery will make your bike go faster with more torque, but it will be more inefficient when you go slowly. If you only go slow, the 36v battery might be better, but you should push the amps up a bit by adding some solder to the shunt in the controller. We need to know the RPM of the motor to give exact guidance.
Click to expand...

??? So say engine/wheel max speed is 25mph and i drive 10mph A 36V gives me more distance then a 48V ?
(just some made up values)
 
Motor are efficient when they are close to their max RPM. If you go higher voltage it'll be less efficient at lower speed but more efficient at higher speed. That's why D8veh told you to get a 36V if you only run at low speed.

Increasing voltage increase your speed and little bit the torque.
Increasing AH increase capacity and doesn't affect speed or torque.

So 48V30ah has 50% more capacity than 48V20ah. Same speed and torque.


At the same speed, both 36V and 48V use approximatiely the same power. Even at lower speed.

I had a switch allowing me to change from 36V to a 72V set up. At same speed, I didn't notice any difference on straight road at 25km/h. But for high load or slope it might be different
 
cwah said:
Increasing AH increase capacity and doesn't affect speed or torque.

So 48V30ah has 50% more capacity than 48V20ah. Same speed and torque.
Click to expand...

I menth the Continues disgarge current. Or something like that :)
I mean i see batterys of 48V 30A that have 15A Cont Disch Amps and 30A " ...Even if no battery used the Amp u sent to engine i mean
 
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