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11 miles to work,what to expect out of 48v 1000w 15ah

Posted: Jun 01 2015 9:40am
by Jimboyr6
Hi all
Need to commute to work 11 miles each way will a 48v 1000w rear hub kit with 15ah battery be ok
I know theres lots of factors that contribute to speed,i would be on a flat run mostly
This type of battery, whats a common crusing speed which would get me there?
Thanks all

Re: 11 miles to work,what to expect out of 48v 1000w 15ah

Posted: Jun 01 2015 10:21am
by e-beach
Jimboyr6 wrote:......I know theres lots of factors that contribute to speed,i would be on a flat run mostly.....
I tend to burn about 27 watts per mile on my mostly flat runs around here. I average about 12mph in my city with many stop lights and stop signs. Afternoon winds can be a problem if I am near the beach in the afternoon and heading west. It isn't too cold around here so the temperature isn't much of an issue except for a few weeks in the winter. Hills, temperature, wind, and the weight of you and your bike are the major factors to think about.
Edit: And of course speed. If you go slower you will get more miles.

The standard rule of thumb around here is volts times amp hours equals watt hours. 48v x 15ah = 720wh / 27wpm = 26.66 miles range on a full charge and a new battery. IMO you should be fine for your 22 mile runs.....but......

To keep your margin for error low, many around here recommend a second battery charger to be left at work and charge at work. This way if you also want to go somewhere after work you will have the option to do so on a fully charge battery.

:D

Re: 11 miles to work,what to expect out of 48v 1000w 15ah

Posted: Jun 01 2015 10:49am
by Jimboyr6
Thanks for info
So at what crusing speed is that at
I know these kits do about 30 mph but how do thay cope flat out all the way

Re: 11 miles to work,what to expect out of 48v 1000w 15ah

Posted: Jun 01 2015 10:57am
by TheBeastie
I have built a pack out of one of those ebike battery casings my self and I was impressed to see a claim of 15ah 48v for such a compact case.
To place 52cells in those packs takes skill and uses every square cm of space available inside, and it also led me to believe the seller that you have refrained from showing must either have very super duper 18650 cells or is lying about the capacity.
If you check here http://em3ev.com/store/index.php?route= ... uct_id=161
Where you can configure 13S P4 configuration of 2900mah samsung 29E (SDI INR18650-29E) cells you can only get a total of 11.0AH, even with the more popular 25R Samsung high discharge cells its only 9.8ah total in the 48v pack.
You can't stick any more cells in those cases full stop.
em3ev is one of the most respected battery pack builders out there with quality cells, some one else putting in higher capacity then them is something to talk about.

Its pretty dubious to believe some mystery seller I am assuming you have dug up on ebay or aliexpress is using barely available Samsung 35E cells that have 3500mah, and its important to remember that using them on a higher discharge rate like 5a its only giving out 2771mAh which is at least 20% lower total capacity, your going to need at least a 6p configuration to cause less burden on 35E cells to get something closer to the promised capacity and most certainly not in that case because you can't fit a 6P configuration in that battery case, would be great if you could but its simply not big enough.

http://www.dampfakkus.de/akkuvergleich. ... =0&akku6=0

Buying a dodgy battery pack is pretty evil as you are rewarding the seller for lying and shafting your self out of capacity and cycle life of your pack, odds are pretty good you will be getting a bigger wh total battery by buying the cheapest one available from em3ev etc then buy from a dubious seller that just likes to put big labels on their products.

Re: 11 miles to work,what to expect out of 48v 1000w 15ah

Posted: Jun 01 2015 11:05am
by nutnspecial
My experience is worst case scenario on high power and/or heavy builds is 1mi/ah.
Mostly I get double or triple that if I'm riding like a normal person, even with a high draw setup.

The 1kw kits wot would have to be at least 2mi/ah to cruise. The effiency will obviously take a hit with more weight, wind resistance, hills, and starting/stopping, but I couldn't imagine it'd be bad enough for you not to make it one way (if that was your question).

Re: 11 miles to work,what to expect out of 48v 1000w 15ah

Posted: Jun 01 2015 11:26am
by wesnewell
At 20mph, flat no wind, you need ~22wh per mile. At 30mph you need ~40wh per mile. A 15ah 48v pack is 720wh. You can do the math.

Re: 11 miles to work,what to expect out of 48v 1000w 15ah

Posted: Jun 01 2015 11:50am
by e-beach
TheBeastie brings up a good point. Make sure you are getting your battery pack from a reputable seller. Also, 30mph would most probably be wide open throttle, or near wot for a 48v 1000w setup, not a cruising speed really.

:D

Re: 11 miles to work,what to expect out of 48v 1000w 15ah

Posted: Jun 01 2015 12:04pm
by Drunkskunk
Your battery has 720 watt hours of power. At 20mph cruising speed, that's about an ideal battery size for 20 miles of reliable range, with reserve. That's based on a battery capacity of 36 watts per mile @ 20mph that we commonly recommend for sizing a battery to your needs. It also happens to work out to 1 amp hour per mile at 20mph, for 36 volt batteries, and you'll see that 1a/mi referred to often.

But if you want to bump your speed to 30mph, then it's good for about 8.5 miles of reliable range. 30mph takes around 2.25 times more power than 20mph. Slow down just a bit, and keep a second charger at work, your battery will be fine.

To get the most life out of your battery, you should only use less than 80%. consider the other 20% a reserve tank. That leaves you with 52 watts per mile if you make 11 mile trips. So you'll need a CA to monitor your use in real time. Find a speed that lets you average 52wh/mi for the whole trip. That will likely work out to 27-29mph average, but factors like weight, wind resistance, stops and starts, and road conditions will change that. You might be able to get faster.

Re: 11 miles to work,what to expect out of 48v 1000w 15ah

Posted: Jun 01 2015 12:44pm
by Jimboyr6
Well this is what i thought iv not seen many 15ah packs he saying his 36v kits are 13ahs
the pic is just a pic of the type but heres the sellers website he said hes getting 1000w kits in soon http://www.electricbike-conversions.co.uk/
I looked at em3ev good quality thay are for sure,but not cheap once u put a kit togeather
Im on a driving ban for 6 months so was hoping to save on shipping,
And bolt a kit on a f/s mountain bike quickly.

Re: 11 miles to work,what to expect out of 48v 1000w 15ah

Posted: Jun 01 2015 1:45pm
by amberwolf
Something to keep in mind: Packs age, and many packs are not of very good quality for whatever reason, and the harder you use them the faster they can age depending on many factors.

So don't expect a pack that's being used to the limit of it's capacity on every trip to keep doing this; it'll lose capacity and range as it ages.

How fast that happens depends on it's quality and how well it's kept in balance.

Balance depends on the charger and the BMS *and* how long you leave it plugged in; most of these things give you no indication of being in balancing mode so you think they're done when really they've got hours or days to go...and eventually end up so out of balance that range is reduced to a very small fraction of what it would be otherwise. :/


How good any pack is, you'll find out when you use it to it's limits a lot. :)

Re: 11 miles to work,what to expect out of 48v 1000w 15ah

Posted: Jun 01 2015 2:11pm
by TheBeastie
Jimboyr6 wrote:Well this is what i thought iv not seen many 15ah packs he saying his 36v kits are 13ahs
the pic is just a pic of the type but heres the sellers website he said hes getting 1000w kits in soon http://www.electricbike-conversions.co.uk/
I looked at em3ev good quality thay are for sure,but not cheap once u put a kit togeather
Im on a driving ban for 6 months so was hoping to save on shipping,
And bolt a kit on a f/s mountain bike quickly.
You kind of suggested a very different battery.
A 48v 15ah battery has a very different total capacity to a 36v 15ah battery.

Re: 11 miles to work,what to expect out of 48v 1000w 15ah

Posted: Jun 01 2015 3:09pm
by Jimboyr6
Yes i know, i was pointing out that the seller also sells a 36v 13ah set up as well

Re: 11 miles to work,what to expect out of 48v 1000w 15ah

Posted: Jun 02 2015 3:18am
by Jimboyr6
So going by this pic u can only get 50 cells in there ?

Re: 11 miles to work,what to expect out of 48v 1000w 15ah

Posted: Jun 02 2015 5:15am
by dogman dan
Well, even if it's only an 11 ah pack, you have enough to get there at 25 mph cruise. Likely you will have 30 mph right out the driveway, but by halfway there it will be slower. Your commute time will be about 35-40 min.

On a cold day, wind in your face, you might have to slow some to make it, but all summer you should be ok to ride 25 mph all the way to work, and have some reserve left in the pack when you get there.

Charge, then return home.

Re: 11 miles to work,what to expect out of 48v 1000w 15ah

Posted: Jun 02 2015 5:25am
by Jimboyr6
Thats just the info i was hoping for thanks man

Re: 11 miles to work,what to expect out of 48v 1000w 15ah

Posted: Jun 02 2015 5:34am
by dogman dan
It it really is 15 ah, then you'd be able to make it both ways, but at about 20 mph.

Re: 11 miles to work,what to expect out of 48v 1000w 15ah

Posted: Jun 02 2015 8:58am
by wesnewell
An 18650 50 cell pack will be a 36V 10s5p pack, not a 48V pack. Top speed with a 36V pack will be ~20mph. For a 13s4p 48V pack you need 52 cells.

Re: 11 miles to work,what to expect out of 48v 1000w 15ah

Posted: Jun 22 2015 5:10am
by Jimboyr6
Anyone had any experience with pandabikes thay do a 48v 1000w 11.6ah bottle battery kit but its £650,
Wheres peadlease do a kit with a 10.4 ah battery £500
Is pandabike worth it for the extra 1.2ah ??

Re: 11 miles to work,what to expect out of 48v 1000w 15ah

Posted: Jun 22 2015 5:32am
by meelis11
No one has mentioned one important factor - do you plan to pedal too? I pedal and commute about 33kmh (21mph) and I can get about 8-10Wh/km. I charge only once a day - after 30km (20miles). I have 10Ah 44V battery (12S LIPO) and daily I use about 5-6Ah
If you pedal you can double your range at 20mph.

Re: 11 miles to work,what to expect out of 48v 1000w 15ah

Posted: Jun 22 2015 7:17am
by Jimboyr6
Yep im gona pedal off the line to help and at all speeds as i know it helps alot

Re: 11 miles to work,what to expect out of 48v 1000w 15ah

Posted: Jun 22 2015 7:35am
by davec
your lucky to have an all flat terrain- i can;t comment on that battery or what AH it is capable of however
basic calculation shows that this battery is plenty to get you there and back - there are many variable wind/outdoor temp/ speed etc.. so it's always good to have more than you need
i would recommend getting a power meter as well so you can gauge you consumption.

general consumption is *typical 9-12 Wh/km - going 30 km/hr 20mph* or *going really fast 14-20 Wh/km speeds like 28mph*
if you were to go constant 20mph on a nice day with no peddling that would be 22miles ( 35km) * 15wh/km(should be 13 but lets go over the estimate a bit) / 52 = 10ah
i do 44 miles a day and consume 20ah -22 to work 22 back - on my way to work i do constant 28 mph.. i usually see 12-13ah when i arrive at work... sometimes 15 if its cold out or windy... my way home i take it easy only going 20mph average and consume about 8-10ah.. i do have some hills on the way but i peddle a bit to help the motor...

Re: 11 miles to work,what to expect out of 48v 1000w 15ah

Posted: Jul 13 2015 5:29pm
by Jimboyr6
So thanks for all the help with this
update is
Bought a kit from panda bikes,which i can recommend, he seemed genuine enough about his kits and the only one with a good quality bottle battery in uk.
11.6ah samsung cells so went for it
It's Got the waterproof loom as well, i had my worrys but it fitted to my kona kula hard tail perfectly
First proper ride today home from work 11miles flat out mostly 25mph it managed 28mph if I pedalled, it was only a couple more mph if i helped
Done in 28 min, and the screen still saying half battery still, im happy with that
Its no stealth bomber but it will get me through the shit weather days and save my bomber from getting worn out :lol:

Re: 11 miles to work,what to expect out of 48v 1000w 15ah

Posted: Jul 13 2015 6:58pm
by Baron
For my 1000w 48V build I had to upgrade the freewheel on my bike because pedaling did very little at 25+ mph. Just couldn't keep up with the motor. Have a 48t chainring in the front and the hub motor came with 14t smallest on the rear. Upgraded to 11t-28t and now I can keep up with the motor around 30-32mph.

Something to keep in mind if you have the same problem.

Re: 11 miles to work,what to expect out of 48v 1000w 15ah

Posted: Jul 14 2015 1:15am
by Jimboyr6
Baron wrote:For my 1000w 48V build I had to upgrade the freewheel on my bike because pedaling did very little at 25+ mph. Just couldn't keep up with the motor. Have a 48t chainring in the front and the hub motor came with 14t smallest on the rear. Upgraded to 11t-28t and now I can keep up with the motor around 30-32mph.

Something to keep in mind if you have the same problem.

Yeah i did get a different freewheel 11t-32t which seems to work fine
How are u getting 30+ mph have u a different controller ?