XB-700Li True Battery Capacity is 40AH?

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AlbinD
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XB-700Li True Battery Capacity is 40AH?

Hello All happy XB-700Li owners;

I am not an owner, and before becoming one ...I wonder;

Anybody has managed to verify marketing claims regarding 40AH battery capacity used in XB-700Li? 1 hour capacity (1C) or 20 hours (C/20) capacity? By measuring it, or by opening the battery box to see what is written on individual cells?

48Volts and 40AH amounts to almost 2KWh of energy storage. 1KWh Lithium battery packs currently sell for $400+ on eBay ... hence my suspicion.

As you probably know, XB-600 comes with 20AH Lead Acid batteries. 20AH is a capacity at 20 hours discharge rate (C/20), which is a common method of measuring capacity of lead acid batteries. The same lead acid battery at 1 hour discharge rate has only some 10AH capacity. This is sometimes called a Perquet's effect, or Perquet's law.

Because Perquet's effect does not apply to Lithium batteries that much, effective range of XB-700Li should be 4 times the range of XB-600, if 40AH marketing claims are true.

Do you indeed experience 4-fold increase in range with XB-700Li, in comparison to XB-600?

Thank you All in advance, Albin.

reikiman
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Re: XB-700Li True Battery Capacity is 40AH?

The name you're looking for is Peukert ... and it does apply to lithium batteries but they tend to have lower internal resistance which is why there's less voltage drop under discharge.

I believe they're using thundersky cells?

I've not looked inside one either. Hopefully someone who has one of these can comment.

- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
- Electrified Electra To

AlbinD
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Re: XB-700Li True Battery Capacity is 40AH?

40AH Thumdersky cells would cost $1,200 if purchased individually, all 21 of them.

If they are indeed using these cells in XB-700Li, then I am sold. These are solid batteries used in electric cars.

For those interested, Perquet exponent is best explained here:

http://www.39pw.us/car/peukertEffect.html

For those concerend about a lack of Battery Management System in XB-700Li, from another thread, there seems to be a concesus that Tundersky cells do not benefit from a BMS that much, provided they are balanced to start with. An interesting thread on the subject can be found here:

http://www.diyelectriccar.com/forums/showthread.php/thundersky-lifepo4-real-world-experience-thread-24433.html

Regards, Albin.

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