Introduction from LifeBATT UK Distributor

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ChopperMan
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Introduction from LifeBATT UK Distributor

Postby ChopperMan » Mon Oct 15, 2007 4:55 pm

Hello All,

I am the UK distributor for LifeBATT LifePO4 Batteries. Our website is http://www.lifebatt.co.uk Please have a look at the website and I am happy to answer any and all questions about LiFeBATT batteries in this forum.

On a personal note, as you might see from my username, I'm into electric powered choppers. I design and build my own frames, but using cycle parts.

My current project is 8 feet long, has a 3" wide, 28" diameter rear tyre and is powered by a Puma hub motor with 36V 20Ah LifePO4 pack. Peak power is approx 1,200 watts. Top speed 23+mph.

Kind regards,

Ian Goodman

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ChrisB
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Postby ChrisB » Mon Oct 15, 2007 9:59 pm

Hi Ian,

Those batts look interesting but I'm slightly confused with .........

Performance

Continuous Discharge Rating: 12C (120Amps from our 10Ah Cell)
Peak Discharge Rating: 14C (140 Amps from our 10Ah Cell) for 18 second burst.


It says 12C from a 10Ah cell, surely that puts the battery spec it at 0.8A over 12hrs ? so is the 120Amps peak ? but then it says 140 amps 18 secs but it then says that its 14C ???

Dosnt make sence really ??

ChrisB
I reject reality and substitute my own !!!!!!

ChopperMan
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Postby ChopperMan » Mon Oct 15, 2007 11:04 pm

ChrisB wrote:Hi Ian,

Those batts look interesting but I'm slightly confused with .........

Performance

Continuous Discharge Rating: 12C (120Amps from our 10Ah Cell)
Peak Discharge Rating: 14C (140 Amps from our 10Ah Cell) for 18 second burst.


It says 12C from a 10Ah cell, surely that puts the battery spec it at 0.8A over 12hrs ? so is the 120Amps peak ? but then it says 140 amps 18 secs but it then says that its 14C ???

Dosnt make sence really ??

ChrisB



Hi ChrisB,

Sorry but I don't know your level of technical knowledge, and I'll admit, I am not an expert. But I do have 4 or 5 years of playing with electric bikes and scooters. So here is my understanding of the subject.

"C" is a measurment of the rate of discharge (or charge) for a given battery capacity (Ah). So, if you discharge a 10Ah battery at 1C rate your motor is drawing 10 amps from it. If you discharge it at a 2C rate, your motor will be drawing 20 amps, and so on.

The LiFeBATT cells allow you to draw 12C, 12 X 10Ah = 120Amps. Then you can burst discharge, usually when you pulling away from a standing start or excellerating, your motor could pull up to 140Amps for 14 seconds before it had any adverse effect on the battery.

For most electric cars/motorcycles we will be offering 48V 60Ah packs, which can be connected in series or parrallel to give you your desired spec. These packs have the same discharge rating, 12C, so with a 60Ah pack your motor could draw 720Amps. That should give you some good excelleration 8)

Ian

MalcolmB
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Postby MalcolmB » Tue Oct 16, 2007 7:43 am

Hi Ian

Great to see that we have a distributor for LifeBatt here in the UK.
The specs for the battery do seem a little odd, as there's such a small difference between the continuous and peak discharge rates.
From what Don Harmon (US representative of LifeBatt) has said on other forums, I understand that more detailed specs will be published shortly. I know that some of these batteries are being tested by American EV enthusiasts and their first impressions have been very good. I look forward to the results.

You say that you'll be selling individual cells early next year. Will you be selling BMS modules separately as well? The modular packaging looks great, but for my own application, a motorcycle, I would prefer to be able to package cells myself to get the ideal configuration.

Regards
Malcolm

ChopperMan
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Postby ChopperMan » Tue Oct 16, 2007 11:17 am

Hi Malcolm,

I have been working closely with Don and the spec I have quoted on the website is the most up to date, independently verified, data.

We do expect to publish an improved 'burst' spec, but we are being cautious. I would rather be able to improve the rating as time goes on than have to turn around to anyone and say that we were wrong.

The strategy for selling individual cells has not been established, just that there will be sufficient production to be able to offer cells on an individual basis. The cells will obviously need a BMS, so logically we will be offering one. But again, the details are unavailable at present.

I will of course keep my website up to date with the latest information and try and keep you all posted on the forum.

I would be interested to see what kind of space/layout you have/need for your motorcycle. Would 48V 60Ah be sufficent for your project?

Kind regards,

Ian

MalcolmB
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Postby MalcolmB » Tue Oct 16, 2007 12:29 pm

Thanks for the quick answer Ian. There's a picture of my bike here: http://batteryvehiclesociety.org.uk/forums/viewtopic.php?t=264&start=0 My current 60V 26Ah lead acid pack gives me 15 miles range, so 60V 60Ah of lithium should easily give around 50 miles. At current prices though, that would be well outside my budget.

One option would be to start with a 60V 20Ah pack. That would deliver roughly the same energy as my existing pack but at only a third of the weight, so should give a small increase in range. I could then add more capacity when I can afford it. I need to think about it some more.

I'm interested in how these batteries are charged. I see that the ones for sale now are built up from 12V 10Ah modules. So if I wanted a 60V 10Ah pack it would be made up of five 12V modules. Would you supply a 60V charger for that pack?

Your bike looks like fun, by the way. The Puma sounds like a great little motor.

TonyM
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Postby TonyM » Tue Oct 16, 2007 12:47 pm

Just a quick thank you to Ian for a direct reply to a question posted via his web site

ChopperMan
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Postby ChopperMan » Tue Oct 16, 2007 11:41 pm

MalcolmB wrote:Thanks for the quick answer Ian. There's a picture of my bike here: http://batteryvehiclesociety.org.uk/forums/viewtopic.php?t=264&start=0 My current 60V 26Ah lead acid pack gives me 15 miles range, so 60V 60Ah of lithium should easily give around 50 miles. At current prices though, that would be well outside my budget.

One option would be to start with a 60V 20Ah pack. That would deliver roughly the same energy as my existing pack but at only a third of the weight, so should give a small increase in range. I could then add more capacity when I can afford it. I need to think about it some more.

I'm interested in how these batteries are charged. I see that the ones for sale now are built up from 12V 10Ah modules. So if I wanted a 60V 10Ah pack it would be made up of five 12V modules. Would you supply a 60V charger for that pack?

Your bike looks like fun, by the way. The Puma sounds like a great little motor.



Hi Malcolm,

We are working on a standard 60V/48Ah Motorcycle Pack which will be available in the Spring of 2008. This pack can be modified as required to build different configurations and will have a single charger, as well as the normal integrated BMS.

Presently, to build up your 60V 10Ah spec you would need to use five 12v modules and chargers. Not an ideal solution.

If you can wait till the new year, a greater variety of packs/chargers will be available and suit your needs much better.

Yes the Puma motor is great, and pulls like a train. The new Chopper is now rolling and sucked 1.2Kw during accelleration. With no brakes yet it was a bit hairy, but very cool. 8)

Ian

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booboo
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Postby booboo » Wed Oct 17, 2007 10:18 am

Test riding big hairy choppers with no brakes....so cool, a man after my own heart :twisted:
London to Brighton on a Sinclair C5 - 6/5/07 - what a trip !
Ford Explorer 4.0 v6 petrol for everyday abuse - thank God for LPG
Sinclair C5's (Plus "c5alive.co.uk" ) as a hobby

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ChrisB
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Postby ChrisB » Wed Oct 17, 2007 8:51 pm

ChopperMan wrote:
ChrisB wrote:Hi Ian,

Those batts look interesting but I'm slightly confused with .........

Performance

Continuous Discharge Rating: 12C (120Amps from our 10Ah Cell)
Peak Discharge Rating: 14C (140 Amps from our 10Ah Cell) for 18 second burst.


It says 12C from a 10Ah cell, surely that puts the battery spec it at 0.8A over 12hrs ? so is the 120Amps peak ? but then it says 140 amps 18 secs but it then says that its 14C ???

Dosnt make sence really ??

ChrisB



Hi ChrisB,

Sorry but I don't know your level of technical knowledge, and I'll admit, I am not an expert. But I do have 4 or 5 years of playing with electric bikes and scooters. So here is my understanding of the subject.

"C" is a measurment of the rate of discharge (or charge) for a given battery capacity (Ah). So, if you discharge a 10Ah battery at 1C rate your motor is drawing 10 amps from it. If you discharge it at a 2C rate, your motor will be drawing 20 amps, and so on.

The LiFeBATT cells allow you to draw 12C, 12 X 10Ah = 120Amps. Then you can burst discharge, usually when you pulling away from a standing start or excellerating, your motor could pull up to 140Amps for 14 seconds before it had any adverse effect on the battery.

For most electric cars/motorcycles we will be offering 48V 60Ah packs, which can be connected in series or parrallel to give you your desired spec. These packs have the same discharge rating, 12C, so with a 60Ah pack your motor could draw 720Amps. That should give you some good excelleration 8)

Ian


Hi Ian

Now your worrying me :shock: I've always understood the C-rating of a battery was its maxium "design" discharge current, i.e a battery rated at say 100Ah C5 will support a discharge curve of 20Amps for 5hrs maxium, anything outside this discharge curve is quite likely going to cause the battery issues in the long term hence why you try to match your discharge curve to the batteries C-rating or hourly rating, which is what I thought was the same thing :?: :?
Yes a 100ah C5 rated battery would supply far more than 20amps in fact several hundred amps if required but it wouldnt last very long doing it and it wouldnt supply the Ah rating that it claimed and will in the end damage the battery.

So your saying that the life batts are good for 120amps or 140amps but you dont give it an hourly rating ?? you say the 140amps is for 18secs but then whats left ???

Now I'm totally confused.

So what would you say the continouse discharge current until flat or to 80%DOD, which is a standard measurement, of say the 48v 60ah pack is ??.

ChrisB
I reject reality and substitute my own !!!!!!


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