"how far does a 48V12AH battery go?

[dfmerrifield]

I had gotten my Magic Pie up and running about 3 weeks ago and she runs real nice.  But, as advertised on the http://www.goldenmotor.com/magicpie/magicpie.html site, says that I should get around 60 km (or 37 miles) out of it "Ranges(full electric mode): 45Km(36V12AH) or 60Km(36V16AH, 48V12AH)".  I have the 48V12AH and thought I would get maybe 50 km (32 miles) out of it at least due to the winds we have out in the country where I live.  This is why I ordered the 48V12AH is for the distance due to it being 25km (16 miles) each way to work.  The roads are all black top and fairly flat as I live in a rural farming area and you can look for miles all around and see nothing but farm fields for miles and miles.  I have tried everything, including: pedal assist while starting, going over over passes and tried running her at different speeds like 25 km, 32km then 40 km (25 miles hour) the whole time with CC on until the battery died and still get the same result every time, depending on the wind and if it's up my ass or not, 24km (15mi) to 29km (17mi) average riding distance and that's it.  The bike only goes 40 km (25 miles hour) with the wind at my back and maybe average 35 km (22 miles hour) with a good breeze to the face.  Don't even ask about going over the over passes, like going over the 401.  I tried it once without peddling to assist it get over the "hill" but she slowed down to a slow crawl and I had to give her a lot of help to get going.  She goes real good down the other side though!  The thing is I know it's the Battery that is doing the shutting down.  I have to turn off the key to reset the battery to get it to start up again.  The longer I let it sit the little farther I get to go before the battery shuts down again.  Now as I said before, I live out in the country with hardly no stops and goes at all.  The closest town to me is 8.8 km (5.5 Miles) one way with no stops. and the next is 16 km (10 miles) with no stops. 

So, the question is::: Is this normal or is there something wrong with my battery or the set-up with-in it. and yes I did check the voltage from the charger and the battery and both say 54.6V.  The funniest thing is, the battery shuts down just as the bike just starts to slow down maybe a few km (2-3 Miles hour) then boom, OFF she goes.

I love my Magic Pie but, she don't seem to want me to ride her all that too far.  She wants to stop for grub all the time.  Need help figuring out a way to get her diet to last a bit longer than only average 25km (16 mi).  I have been pondering an other battery and running two of them, but, I shouldn't have to if I am supposed to be able to get 2.5 time the distance I am getting now.

Thanks
Don

[Cornelius]

Strange...
On the 'EV Battery' page, they says "Ranges(full electric mode): 38Km(36V12AH) or 50Km(36V16AH, 48V12AH)"

I get an average of 35km out of my 36V, 16Ah battery...

[GM Brazil]

Strange...
On the 'EV Battery' page, they says "Ranges(full electric mode): 38Km(36V12AH) or 50Km(36V16AH, 48V12AH)"

I get an average of 35km out of my 36V, 16Ah battery...

Those ranges looks more realistic for a 250W motor, what motor do you use?

[dfmerrifield]

Cornilius, Yes I did see these spec's too. ("Ranges(full electric mode): 45Km(36V12AH) or 60Km(36V16AH, 48V12AH)") on the site and at others too.  Just was making a point towards the advert's that were online through http://www.goldenmotor.com/magicpie/magicpie.html.  Then other places on the site you see "Ranges(full electric mode): 38Km(36V12AH) or 50Km(36V16AH, 48V12AH)".  So, I did figure I should get more realistic and go with the lower of the two and go from there as I said above:

I have the 48V12AH and thought I would get maybe 50 km (32 miles) out of it at least due to the winds we have out in the country where I live.  This is why I ordered the 48V12AH is for the distance due to it being 25km (16 miles) each way to work.

I figured I should get at least 40 km (25 mi) out of it and maybe even if lucky 45 km (28 mi).  I run her with 29.47 kg (65 lb) air in my tires (real hard with little ground to tire resistance).  I weigh 88 kg (190 lbs) and riding on flat black top even with the wind to my back and no stop and go at all, I still only get an average distance of 25 km (16 mi) and max 40 kph (25 mph) then the motor backs off.  The motor keeping down to a max 40 kph (25 mph) is good though, for me anyway.  'Cause, if it went faster I know I would use it and ya know you gotta watch out for those idiots in blue.  But, only getting half the distance out of my battery is kinda getting on my nerves when the adverts' say much more.  Was kinda hoping I could go the 51 km (32 mi) round trip to work and back with a bit of pedal assist (Hell, I'm 50 yrs old and need the exercise) but, now I have to worry about even getting there one way.

Thanks
Don

[Cornelius]

I use the 750W standard hub-motor (not magic-pie), and weighs around 80kg...

Another thing; not long ago, they said on most of the pages: 'Get 45km out of 36v/16Ah and 48v/12Ah', not much else...

With my motor, i'd say around 35km with no pedaling and close to full throttle, and 45-50km with light pedaling and moderate throttle... (I haven't tested the latter properly yet; i'm too lazy, and having too much fun just cruising... )

[GM Brazil]

For the 36V16Ah battery you have 576Wh of energy, so with a 750W full throttle and considering 78% of efficiency:

750W/0,78=961,54W of consuming power, so:

576Wh/961,54W=36 minutes or 0,6 hours of use.

Then you can multiply your max speed by those 0,6 hour and check if it fits your range if not, we need to change the efficiency value.

[Cornelius]

Now, we cannot say 'it uses 961W at full throttle'? it would depend entirely on the load. With a light downhill I would guess under half of that...

At what load does the 750W use max energy?

Last time my controller cut due to low power, I had been riding a total of 1hr, 14min from full charge, and avg speed was around 31km/h... That would be a 38km trip.

[dfmerrifield]

I just got done redoing my MP over the last couple of hours.  I went and got a new set of tires and put them on.  They are more like cheater slicks to me so, maybe a lot less road restriction.  I also had to straighten out my MP wheel, it was like riding on an egg.  "It cam that way from Golden Motors too! The spokes were all out of whack.  Some where way too tight and most where so loose, any longer running it I would have some of them actually come all the way off. And I am not kidding about that either!  It was so bad that the tail light bracket that came with the rack 002 actually broke off while riding down the road just from the vibrations in only a few rides.

I am gonna go for a ride and see how much better it is and how far it goes now  .

As for GM from Brazil, don't let figures that come out of a lab or out of a book fool you.  Here in the real world, those figure only work on paper.  In real life things are totally different!

I want to go for a ride to town for a bit and see how things go now with my bike and after I come back I will give you some for instances.

Cornelius, I know what you mean by loving to just cruise!  Anyway I should be actually getting the same distances you are getting with your bike.  Mine don't make any difference if I go full throttle or not.  Like I said above:

I have tried everything, including: pedal assist while starting, going over over passes and tried running her at different speeds like 25 km, 32km then 40 km (25 miles hour) the whole time with CC on until the battery died and still get the same result every time, depending on the wind and if it's up my ass or not, 24km (15mi) to 29km (17mi) average riding distance and that's it.  The bike only goes 40 km (25 miles hour) with the wind at my back and maybe average 35 km (22 miles hour) with a good breeze to the face.

 

I am gonna find out if redoing the rear end and new tires make a difference (which I know it will a bit but, how much is to be seen).

Be back in a few and will let you know how it went.

Don

[dfmerrifield]

I AM NOT REAL IMPRESSED!

Bad day for Magic Pie!

Too pissed off to say anything right at this moment!

13.4 miles and done then and to peddel the rest home out of 20 miles?

Not a happy camper right now!

Tom! get a hold of me as soon as you can so we can fix this?

It has to be a bad cell in the pack.  It's getting worse every week.

The amp draw is getting smaller and smaller all the time.

Don

[GM Brazil]

As for GM from Brazil, don't let figures that come out of a lab or out of a book fool you.  Here in the real world, those figure only work on paper.  In real life things are totally different!

That was a very simple calculation that does not consider a lot of aspects of real life, but during my real life tests using my real life bike at a real life road, I can predict pretty accurate my range (not with that simple equation), considering that I live at a very flat city.

That equation helps, but of course it can not be considered in real life situation with a lot of starts and stops, hills, etc.  But gave you an idea of what to expect, didn't??

And also, books and labs shows and study real life scenarios, if you use that information or not is your call

13,4 miles is a real scenario to me when I do not pedal together and runs at full throttle all the time, with a lot of starts and stops using my 48v12Ah with the Magic Pie, but generally I got 25km to 30km with pedaling at starts and high grade up hills.

[GM Canada]

This is a post I made from another topic in the forum

After re-reading this thread I just realized you don't just want to farther but you want to go faster. Two 48v12ah batteries in paralell won't make you go faster, but it does allow you to go full speed further. My treck to work is ten miles up hill and downhill back. I used to do it on a 36v500 with one 36v16 ah battery with alot of peddling and gentle thumb work on the throttle ( my weight is a serious factor in this equasion, but we are not discussing that). Then I upgraded it to a 48v1000 watt and a 48v12ah battery. It was faster but still alot of peddling and gentle throttle. Now I have two 48v12ah batteries fly full throttle both ways and sit back and drink my coffee!

My trek to work is 20 miles round trip. I found that with one battery of either 36v16ah or 48v12ah barely makes is with alot of peddling. That is why I upped the anti to 2 batteries. One my way to work which is mainly uphill at full throttle I notice I am burning 1000-1100 watts ( I use a cycle analyst to get live readings ) and on my way back down hill still at full throttle I am burning 600-900 watts. I never really realized how much power I was burning until I was able to read these numbers live with the analyst. Even on my site my calculations for distance are based on burning 250w to go 32kph on flat ground but with my weight this is unrealistic. My wife however is only around the 100 pound range and can go the same distance on her bike with one 36v16ah battery as I can with 2 48v12ah batteries.

I have written Tom to, hopefully we can get some clarity on the situation.

Gary

[dfmerrifield]

  Thank You for the call Gary!  If anyone needs to order anything for their bikes, ether a full kit or just parts, go to GoldenMotor.ca and get it from Gary their.  He is the most stand-up guy I have had the privilege of dealing with.  I ordered my MP at noon on a Tuesday and the very next morning at noon I received my Kit and Battery.  I am a Mechanical/Stationary and Environmental Engineer and have an Inter-provincial Class A Refrigeration License and own a Refrigeration and Mechanical Company.  I have to deal with many different people working in my business and Gary stands out in the lot!

  Mr GM from Brazil, as I tell all the students that come and go through my business for their hands on Engineering or Mechanical training.  "Do what the teachers want you to and learn the theory from the books and lab reports then when you come here to work, forget 75% of what you learned there and we will teach you the right way to do it."  Because all theory applications will not work on all practical applications.  Every job is totally different from the other just as every e-Bike situation is and always will be from one another.

  Now here is the Three Week scenario to show why and how I know the Battery is going.

1. I  had the kit for one week before I was able to put the thing together.  Had to work out of town as usual.  The first week after running it up and down the road to check it out, I had real quick take off and got up to 25 or more mph.  Toke her for a ride to town, that is just over 10 mi one way, to make my bank deposits.  I did not give it any pedal assist to see how far she would go before the battery died.  She ran at 25 mph against the wind and 28 to 29 mph with side gusts and made it all the way back home when the red low power light came on "and that was with heavy winds all the way there and most of the way back.  That was as cool as cool could be to me.  GREAT!  So, 2 days later I did it again, the same exact thing but this time I ran the CC and kept it at 20 mph and the distance was quite less.  I had to pedal the last almost 1 mile and the wind gusts were half of what they were 2 days earlier.

2. Went back to town to the bank again for something to do and test her out again.  With hardly no winds, just a light breeze off the lake and she only went max 25 mph and down to 22 mph.  Thought maybe the battery needed to sit on the charger a bit longer.  So let it go for now.  Two days later, went to the bank again and couldn't get no faster than 22 mph so set the CC at 20 and with some wind down to 18 to 19 mph.  Now that got me thinking, there must be something wrong.  Taking the same roads at the same time of day and getting totally different results.  So that weekend I went up the road to give my Dad a hand with his trailer, it need some welding done.  With a fully charged battery, I would only get up to 20 mph and would not climb over the highway so I had to pedal up it and got there and she slowed down to 18 mph and that is only 5 miles down the road and on the way back started out for the first, not even 1 mile, got 18 mph then slowed right down to 11 - 12 mph at full throttle and I pedaled all the way back home with it and still died 1 mile from home.  I did have some extra weight with me, had a some welding equipment with me in a back pack, not much only about 35 -40 lbs.  Got me thinking again, there is something wrong here.

3. Yesterday!  Started to go to town and hit the bank and test out the new tires and the rear wheel after the great fix-up.  I got half way there and decided "There ain't no way I am gonna make it all the way there.  I had no power at all!  With no wind at all, not even a slight breeze, she would only get a max of 18 mph and that was only for the first few miles and started going down from there.  So I headed to the other town that is only 5.5 miles from home to hit the store and she died 1 mile from the store!  I pedaled the last mile there and tried the battery on the way back and got less than a half mile so tried pedaling the rest of the way home and had to push it the last 2 or so.  Today, I went to see what she would do again (SUCKER FOR PUNISHMENT) went 4 miles up the road to drop off a paycheck and the last red light came on about 1 mile from home and she died just in front of my house.

So Guess What?  That tells me the battery is dying.  Just like in a car battery, your meter may read a full charge but, if you have a bad cell in it, you are not going to be able to start it.

[dfmerrifield]

Mr MP from Brazil, as per your quote:

13,4 miles is a real scenario to me when I do not pedal together and runs at full throttle all the time, with a lot of starts and stops using my 48v12Ah with the Magic Pie, but generally I got 25km to 30km with pedaling at starts and high grade up hills.

From day one. I never ever got close to your 25 km to 30 km and I pedal assist always going up any kind of up-grade and always while starting off and I live in the country and have no stops and starts at all til I get to either town and no difference at 15 mph, 20 mph nor 25 mph.

I wish I did get your results.
Don

[GM Brazil]

Hello Don,

I'm an Aerospace Engineer and I use a lot of what I learned everyday. I was told a lot of times that at real scenarios most of the knowledge I had from the undergraduate Mech. Engineering and aerospace masters would no be used, but in rocketry and turbo-pump design this is not correct -  I really use a lot of what I learned in an everyday basis. For most of my other colleagues that gone to work at other industries it is like you described, most of them works as administrators and not designing for the aerospace industry like me.

Considering the detailed description of your use is obvious that you have some problem, the battery just can not give you enough current. I have close results with my calculations because my battery really works as expected, it is not your case. Claim your warranty!

Check this: http://www.batteryuniversity.com/partone-24.htm

Bruno

[dfmerrifield]

Hey Bruno

Yep! Yep! Yep!  Definitely Bad Battery!

Been on the charger for over 8 hours now and still trying to charge up.  The charger is so "HOT", I picked it up after feeling how warm it was and could not keep my hand on the bottom of it for more than 3 seconds.  It was way too hot to handle.  It's always been just a tad warm and only on one side and at about the 4 hour mark would shut down.  Now, over 8 hours and still going strong.   Gonna leave it on and see how long it takes to shut down if it does.

I did check out that site.  Pretty much what is there is general knowledge (well. to me anyway) and nothing there has any bearing on what I was trying to say. But, it's nice to know where it is for future reference.

All I wanted was how far other people are going on one charge so I could use it for a reference to my batteries' properties.

Don