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Associate

Join Date: Jun 2011
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How Long the 48V 10A LiPo4 Battery Will Last?

07/17/2013 11:10 AM

I will be using geared Hub Motor with 48V 500W power by 48V 10A LiPo4 rechargeable battery for my mountain bike.

I am 121kg weight. I will be using the bike for uphill activitity with a slow drive let say less then 15km/ h.

So I like to know, how long it will take the battery to fully discharge, with other variable such as Temperature and etc are constant?

Much appreciated if anybody solve my doubts?

Thanks

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#1

Re: How long the 48V 10A LiPo4 Battery will last?

07/17/2013 11:18 AM

Since you haven't told us the battery capacity (in ampere-hours), we haven't the faintest idea.

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#12
In reply to #1

Re: How long the 48V 10A LiPo4 Battery will last?

07/17/2013 10:19 PM
ItemIndexRemark
Normal SpecificationRated Capacity10Ah/min 9.5Ah

(at 0.2C Discharge)

2A charge

5.0A discharge

Nominal Voltage48V
Internal Resistance≤170mΩ
Weight5.0kg
Dimension65*155*370mm
Charge PerformanceCharge Mode(Standard)CC/CVMaximum Charge : Current 1C, End time 2.5h
Charge Current(Standard)2A
Charge Voltage(Standard)54.6V
Ambiance Temperature-10°C~+55°C
Charge Time(h)7~10
Over-Current Fuse4A/250V(φ5.2*20mm)
Discharge PerformanceDischarge Current(Standard)5.0AMaximum Discharge : Current 2C, 3C Peak,
End Voltage(Discharge)30V
Ambiance Temperature-20°C~60°C

This is the spec for the Battery.

May you help me?

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#2

Re: How long the 48V 10A LiPo4 Battery will last?

07/17/2013 11:19 AM

Many factors that may seem trivial right now will have a big impact on the time to discharge. Different tire pressures (not atypical of the variation typically seen among bikes) could more than double/half the time to discharge.

.

The question isn't answerable, with the information provided, within a sufficiently small range to be helpful. I can speculate it will be a non-zero time...even a positive time.

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#3

Re: How long the 48V 10A LiPo4 Battery will last?

07/17/2013 11:20 AM

Do an energy balance on the system.

Assume the hill is a continuous single gradient. The rate of increase of potential energy in the bike/human system as a result of its going uphill is equal to the rate of decrease of charge energy in the battery multiplied by the overall efficiency of the system, which allows for motor and cable heating, air friction losses, mechanical losses, etc.. The time taken to discharge the battery is then the stored energy of the full battery divided by the discharge rate. If the time taken to discharge the battery is less than the time taken to climb the hill, then the battery just ain't big enough.

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#4

Re: How long the 48V 10A LiPo4 Battery will last?

07/17/2013 11:25 AM

Assuming yo meant it's a 10 Ah 48 volt pack you have 480 watts to work with.

Depending on your load and actual battery discharge efficiency at a 500 watt load you might get 30 - 50 minutes at full output and proportionally longer run time at lesser outputs.

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#6
In reply to #4

Re: How long the 48V 10A LiPo4 Battery will last?

07/17/2013 11:51 AM

480 watts watt-hours

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#13
In reply to #4

Re: How long the 48V 10A LiPo4 Battery will last?

07/17/2013 10:23 PM

Hi Tcm tech,

If I am pedaling ( own energy) , still the battery will dry up in within 50min or less?

or the battery will discharge slowly its enery?

Any chance the battery to last for least 5 hours with pedaling?

Thanks

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#15
In reply to #13

Re: How long the 48V 10A LiPo4 Battery will last?

07/17/2013 10:40 PM

The batterie will last as long as you pedal and don't use the motor!

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#5

Re: How Long the 48V 10A LiPo4 Battery Will Last?

07/17/2013 11:49 AM

It'll get you all the way to the end of the ride.

But, not back home.

Maybe you can equip your rig with a wind generator and solar cells.

This information is readily available by doing a SIMPLE WEB SEARCH.

Battery Basics - Gears Educational Systems

batteries - How to Calculate Theoretical Capacity and Energy ...

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#14
In reply to #5

Re: How Long the 48V 10A LiPo4 Battery Will Last?

07/17/2013 10:27 PM

Thank you for additional info!!

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#7

Re: How Long the 48V 10A LiPo4 Battery Will Last?

07/17/2013 2:58 PM

You should get about 30 min pushing it, and perhaps 1 hour just cruising...

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#8
In reply to #7

Re: How Long the 48V 10A LiPo4 Battery Will Last?

07/17/2013 3:12 PM

I'd think you could push a bike for more than 30 minutes.

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#9
In reply to #8

Re: How Long the 48V 10A LiPo4 Battery Will Last?

07/17/2013 3:35 PM

I would go with at least 20Ah....

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#10
In reply to #9

Re: How Long the 48V 10A LiPo4 Battery Will Last?

07/17/2013 5:11 PM

And good medical insurance as well.

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#11
In reply to #10

Re: How Long the 48V 10A LiPo4 Battery Will Last?

07/17/2013 5:36 PM

Did I win?

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#17
In reply to #11

Re: How Long the 48V 10A LiPo4 Battery Will Last?

07/17/2013 11:18 PM

And the gene pool remains unchanged, and stagnate.

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#16

Re: How Long the 48V 10A LiPo4 Battery Will Last?

07/17/2013 11:11 PM

It sounds like you are talking about pedal assist. With a bike it is important that you have the capability of regenerative charging. While you may only get 1 hour of help or much less, most roads are not all uphill. If you can recharge when coasting downhill instead of using brakes, you can recover energy that was expended going up hill. We live in a mountainous area where a lot of biking is done. A few people have pedal assist units and they do quite well with them. I would think that you will not have over 30 minutes at 15mph uphill before you hit a downhill. That is 30 miles. I know some areas that have longer than that but they are rare. In that case you will just need to pedal harder.

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#18
In reply to #16

Re: How Long the 48V 10A LiPo4 Battery Will Last?

07/18/2013 5:49 AM

Agreed, with the correction that 30 minutes at 15 mph = 7.5 miles. That's probably still longer than most hills.

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#19
In reply to #18

Re: How Long the 48V 10A LiPo4 Battery Will Last?

07/18/2013 9:45 AM

Sorry about the error, late at night, my brain must have reversed the multiply and divide functions. Still, the only additional energy to climbing a hill would be the weight and batteries added to the bike and rider once the battery power dropped off. Just a little harder to pedal after the 7.5 miles. If the hill was a long one it might be better to put in more power all the way up and not use as much electrical energy. I can see that some sort of control of the electrical energy would be desirable.

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#20
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Re: How Long the 48V 10A LiPo4 Battery Will Last?

07/20/2013 10:15 AM

... and the OP said 15km/hr, not 15 mph, which brings it down to 4.7 miles, with no specification of the grade...

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