Is 5 Ah enough ?

Is 5ah Enough ?

  • Yes

    Votes: 10 20.8%
  • No

    Votes: 24 50.0%
  • Sometimes

    Votes: 16 33.3%

  • Total voters
    48

Ypedal

Moderator
Staff member
Joined
Dec 27, 2006
Messages
12,530
Location
Moncton NB, Canada
This past week i've been riding with my neighbors, 10 to 20 km trips going nice and slow..

When i ride to work, late, i prefer going 50+ kph but on group leisure rides 10 to 20 kph is fine, you can talk, zig zag across parking lots, pedal for a km here and there without power..

I found that i get can get into the 10 km per 36wh range ( 1 ah at 36v ) with very light pedaling, using 200 to 300w on gentle hills ..

And knowing this, i have started taking a puny 36v 5ah pack for the trips and get home with 50% left..

Obviously this will not do for the power hungry bunch that many on here are, or anyone with serious hills they need to climb while not pedaling.. but curious to see how many could actually function on 5ah without too much range anxiety.
 
It's not.
Even if your rides are short, you are missing out on watt-hours and some speed due to voltage sag.
My bike on 36 amps will get those suckers warm, and they will sag 1.5-3 volts depending on if it's a zippy or turnigy pack.
This is on 10S and 20C packs.

I run 10ah minimum now because they are just abused less when i do.
When i run 20AH, i get about 0.7v of sag at peak amps.

OK, so you can run nanotech to get around this problem. But running 10AH of 20C gives you equivalent power output and double the range for almost the same price.
 
HAHAHA... no, definitely not...could burn that up in a couple of km's on
my bike in the hills here :lol:

KiM
 
By the way, when i had a 14 amp "250w" kit, on flats, 5ah was fine and good. I could get 12-14 miles out of that pack. That's because low speeds = super efficient. And the amp draw was so low that it wouldn't stress the lipos out at all.

Yeah, but how many of you are running under 20 amps and under 20mph....

..mmhm, i thought so :mrgreen:
 
I run under 20 amps and 20mph.

Ypedal said:
have started taking a puny 36v 5ah pack for the trips and get home with 50% left..
Sounds like my typical ride.. 250 watts might not be 2500 watts, but its still watts you wouldn't have otherwise. Great help for pulling cargo up hill.
 
I should clarify 5A-h at 1000V, enough. 5A-h at below 100V, not enough to get me to the nearest grocery story :mrgreen:
 
Ypedal said:
Obviously this will not do for anyone with serious hills they need to climb while not pedaling

Spent the entire summer of '08 climbing 1,600ft over 8 miles to work with just ~5.2ah @ 87v through 6 Milwaukee packs & a 4011. Sure I had to pedal moderately as well & slurped the packs to their LVC every time, but it worked really, really well. I really miss that setup a lot actually. :)

DSCN3504.JPG
 
grindz145 said:
I should clarify 5A-h at 1000V, enough. 5A-h at below 100V, not enough to get me to the nearest grocery story :mrgreen:

I'd like to see someone finally do 1000v...

[youtube]PXiOQCRiSp0[/youtube]

Would need to use a small version of this for a connector :mrgreen:
 
At an average moving speed of 17mph with me pedaling along, my 350W geared hub consumption is 8.54wh/mi. 44.4V x 5AH = 222wh would give me a range of 26 miles. Without pedaling the avg speed is 14mph at 13.34wh/mi for a 16.5 mile range. So yeah, 5AH is enough for me.
But my 10AH pack weights only 7.5lbs so I don't really see the need to have a smaller/lighter pack.
 
Erm, 26 miles on 5ah? that doesn't seem right. I have never heard of a setup that efficient.
Is that pedaling with the throttle all the way down?

My record on 5 ah is 14 miles ( pedaling ) with a 250w kit, that's on flat land.
 
I report what I ACTUALLY observed and measured. No speculation, no guesstimate. My numbers are actually not that great, someone else has already reported less than 8wh/mi on the same set up.

My 8.54wh/mi is with FULL throttle with me pedaling at about 65rpm non-stop on a 50 mile ride in Houston (basically flat).

And once again (and again) you brought up Amp-Hour without voltage.
 
Sorry, but that's just hard to believe. Generally all ebike kit / ebike producers selling low-powered motors like that advertise ratings of 20-25 miles per 10AH.

You are getting almost double my best efficiency with a motor that consumes more amps than mine did.
Are you on a recumbent? using ultra narrow tires inflated at 60psi or more? shaped like a teardrop? weigh in the low 100's figure? if all of the above, that makes sense :p

Nobody has reported efficiency figures like that on this forum.
 
neptronix said:
Sorry, but that's just hard to believe.
Why are you sorry? I'm not trying to make you believe anything.

neptronix said:
Nobody has reported efficiency figures like that on this forum.
Wrong. I don't have time now, but I will show you a link to you can read it yourself and not believing it.
 
neptronix said:
Sorry, but that's just hard to believe. Generally all ebike kit / ebike producers selling low-powered motors like that advertise ratings of 20-25 miles per 10AH.

You are getting almost double my best efficiency with a motor that consumes more amps than mine did.
Are you on a recumbent? using ultra narrow tires inflated at 60psi or more? shaped like a teardrop? weigh in the low 100's figure? if all of the above, that makes sense :p

Nobody has reported efficiency figures like that on this forum.

SamTexas said:
neptronix said:
Nobody has reported efficiency figures like that on this forum.
Wrong. I don't have time now, but I will show you a link to you can read it yourself and not believing it.

Here you go Neptronix, as a favor to you, of course.
Ironically both of these reports are in the "Geared Ebike Kit, DD Kit - 150USD" thread, which you are an active participant who had direct conversations with both of the authors. Even more ironic is that one of the report was about your very own kit. I just can't wait to hear your typical BS response to this. Come on, don't disappoint me.

Ziggurat said:
...
I only measured the Ah on one ride so far, and that was at 10S. Used about 2.3 Ah used over 13.5 km, so about 6.5 Wh/km on a mostly flat route with one short steep hill. I was pedaling a lot along with throttle, and there was very little stop and go.
...

veloman said:
I"m riding Nep's 250w geared kit. I took it 3 miles into work today and used 18.0 watt hours. yes, that's 6 wh-mile. Average about
16mph, 30 ft drop in elevation. Light pedal assist/coasting, it was wet so I didn't go too fast with the pedaling.
....
 
recently I decided to try going for a ride on only 6s 6AH pack. I set the LVC as low as it would go and went for a ride.

I was surprised at how much fun it was. I have a MAC hubmotor so at 12s I was going 30+ mph so at 6s I get about 16 - 18 mph. the best part though was getting about 13wh/mi which means 8+ mi on a 2 pound battery :mrgreen: good times.
 
SamTexas said:
I just can't wait to hear your typical BS response to this. Come on, don't disappoint me.

Ziggurat said:
...I only measured the Ah on one ride so far, and that was at 10S. Used about 2.3 Ah used over 13.5 km, so about 6.5 Wh/km on a mostly flat route with one short steep hill. I was pedaling a lot along with throttle, and there was very little stop and go.
...

OK; that's 8.3 miles on 2.3ah, which would translate to him getting maybe 20 miles on 5AH while 'pedaling a lot'.
Seems like a stretch, but if you are pedaling really hard, i'll believe it since i got 14 miles out of mine with stop and go.

veloman said:
I"m riding Nep's 250w geared kit. I took it 3 miles into work today and used 18.0 watt hours. yes, that's 6 wh-mile. Average about
16mph, 30 ft drop in elevation. Light pedal assist/coasting, it was wet so I didn't go too fast with the pedaling.....

flat land, coasting, drop in elevation, low speed, OK, makes sense that you could get that kind of efficiency.

Is this the BS response you were looking for?
 
neptronix said:
Is this the BS response you were looking for?

No, it is not. And I'm pleasantly surprised. Hats off to you.

I just replaced the stock controller with an Infineon 35A controller in order to try 13s (54.6V fully charged). I just ran a 5 mile circle test, WOT, NO pedaling. Avg overall speed 18.5mph, 15.3wh/mi. Basically flat land (up to +/- 2% grade). Cell_man's 350W front geared kit is a lot more efficient than his claim. And I'm running on big fat knobby 26x2.1 tires at 40psi.

Total weight: 49lbs bike + 135lbs rider.

This is my only hub motor so far, but I'm beginning to wonder if it happens to be the most efficient one. I am very pleased with it.
 
OK, you're 135lbs. There's the difference. You are not an average weight.
I am one hundred pounds heavier than you, and i run smooth 1.85" tires on a 55lb bike ( maybe 50lb now.. )
Am also 6ft. tall. More drag.

Most ebike kits are rated using a ~175lb rider on a heavier bike.

So whenever you claim mileage like that, you need to mention that you have a major gravimetric and volumetric advantage ;)
 
neptronix said:
So whenever you claim mileage like that, you need to mention that you have a major gravimetric and volumetric advantage ;)

I already did, whenever appropriate.
SamTexas said:
...
Performance:
With pedaling: 50 miles range, top speed 23mph, avg speed 17mph. 8.54wh/mile.
No pedaling: 32 miles range, top speed 21mph, avg speed 14mph. 13.34wh/mile.
Total weight: 47lbs bike + 135lbs rider.
...
http://endless-sphere.com/forums/viewtopic.php?f=4&t=29356
 
I don't read every thread on this forum, can't expect other people to do that either. Had never seen that thread before.
So when you mention that kind of efficiency, just sayin, mention the rider + bike weight. Instant and dramatic improvement to your credibility ;)
 
neptronix said:
I don't read every thread on this forum, can't expect other people to do that either. Had never seen that thread before.
So when you mention that kind of efficiency, just sayin, mention the rider + bike weight. Instant and dramatic improvement to your credibility ;)
Dang! I don't give a hoot about improving my credibility.
 
SamTexas said:
Dang! I don't give a hoot about improving my credibility.

That's fine. But when i see someone on here spreading information that looks quite wrong, i step in.
Like for example when DrkAngel said he had a balancing charger..
 
Back
Top