# Battery comparison chart



## Tesseract (Sep 27, 2008)

Hey I.D. - Nice chart! Just a few comments from me:

1. There are three main types of lead-acid battery: AGM (absorbed glass mat, aka "VRLA"), gel-cell (typically used in standby apps only, like emergency lights and UPS), and the venerable flooded (with subtypes - starting, marine "deep cycle", standby "deep cycle, golf-cart "deep cycle", and probably a few others, but all of the aforementioned have different enough characteristics to make them non-interchangeable).

2. 150Wh/km is an extremely optimistic energy consumption figure to me. Then again, I know personally that a 96V AGM pack struggles to get an old VW up to 55mph (88kph), so with a low voltage pack (to me anything sub-120V is "low voltage") it is more likely a given car won't ever be able to go fast enough where aerodynamic drag starts killing the range.

3. How about adding in at least a couple brands/sizes of LFP cells?


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## illuminateddan (Dec 19, 2009)

Hi Tesseract,

Thanks, I'm just doing a straight convert from the 200-400wh/mile mentioned in the wiki. I'm looking at best case scenario?!!?! 
I'm pretty sure the 'lead acid' ones I mentioned are flooded cell/venerable cell deep cycle. 

My main aim is to try and work out what my optimal pack arrangement will be for the space I have. One of my concerns is that my optimal pack of 15x190Ah 8v batteries is 450kg, where as a smaller 10x12v 130ah is only 300kg. Is the 150kg providing more power than it takes to move the extra weight? This is where my physics gets fuzzy/non-existant. 

This chart is definitely a work in progress, so I'm going to try and generalise batteries and weights. Maybe a few graphs? I also discovered that on average pack cost is around $AUD 80 per km and 11kg per km for wet cell/agm batteries!

If anyone has any more battery data I'd be more than happy to add it to the chart and publish it here for general consumption!

Thanks!


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## Jimdear2 (Oct 12, 2008)

Very Nice Chart. 

I asssume that the prices listed are OEM suggested retail? Could you be speciffic in the $ amount column as to which dollar you are quoteing, 
U.S Canadian Australian. etc. <EDIT OOPS I see your from Austrailia.End EDIT>

When/If you add the rows for Lithium, maybe a cost per cycle column would be an eye opener. Just use accepted avarages for the count of cycles for the battery type.

Thanks for the effort, this will save many people a lot of time. I remember the time I spent geting this information in a much more UN organized way.


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## dtbaker (Jan 5, 2008)

looks good, but I am wondering what RATE of discharge you are using for the Ah rating? Is that the 20hr rate?

Although you are in AU, you may be able to get your hands on batteries from US Battery (interstate), which makes a series of FLA for golf carts that really are excellent (183ah at 20hr rate for about $130 each delivered). 
http://www.usbattery.com/usb_us8vgchcxc.html
There may be some other choice available in AU....


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## Coley (Jul 26, 2007)

Gels are not just for UPS and stationary use.

They are used in many handicapped wheeled vehicles.

I started out with lead acid, but have since changed to GELs and the overall handiness (no watering) and the use in 10 degree F temps, show them to be better than the lead acids I had.

They take a charge better and come back up on their own better also.

The most that I have to charge @20 amps is under 2 hours per 6+ miles run.


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## illuminateddan (Dec 19, 2009)

*New updated Battery comparison chart*

Hi all,

Updated chart with some lithium batteries added in for good measure. I made it non model specific for all fla and agm so the table can be used as a straight guide for power/weight. Any ideas for other data will be greatly appreciated!
Thanks

(PS .. Also made my mind up form this chart to go for 35 lithiums to make a 120v 100ah pack. Hoorah!)

D


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## pm_dawn (Sep 14, 2009)

*Re: New updated Battery comparison chart*



illuminateddan said:


> Hi all,
> 
> Updated chart with some lithium batteries added in for good measure. I made it non model specific for all fla and agm so the table can be used as a straight guide for power/weight. Any ideas for other data will be greatly appreciated!
> Thanks
> ...


Well It would be more like 38 -40 cells of LiFePo4 to do 120v.

3.2 v is the nominal voltage for the LiFePo4 chemistry.
38 cells will give you 121.6v nominal.

I think you have not regarded the difference in peukert effekt for the LiFePo4 as to the LA cells.
Also the column cost/cycle would be more interesting if it was cost/driven km. just divide the cost/cycle with the range/cycle. That is far more interesting.

Is there a typo in the last SE spec for the 400ah cells?
I find it hard to believe that the 400 ah SE cell weighs the same as the 200ah TS cell.

otherwise this is a good comparison.
I did about the same kind of calculations before chosing my TS pack.

Best regards
/Per


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## dtbaker (Jan 5, 2008)

*Re: New updated Battery comparison chart*



pm_dawn said:


> Well It would be more like 38 -40 cells of LiFePo4 to do 120v.
> 3.2 v is the nominal voltage for the LiFePo4 chemistry.
> 38 cells will give you 121.6v nominal.


...and the tricky thing about the Pb amp-hr ratings are down-rating it to a 1 hour value. For instance the US batteries I used (us8vgchcx) have a 183 ahr (20hr) rating, but 'about' 100ah at a 1 hour discharge rate.


d


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## pm_dawn (Sep 14, 2009)

@dtbaker:
I think he has taken care of that pretty well with the Peukert effect of 55%. in the column Total Power @ 80% DOD inc P-FX. 

What I was apposing to was that the same P-fx is used for the LiFePo4 cells. They tend to have little or no loss due to P-fx and therefore should have the rating as straight of the 80% DOD. So for the TS 160 pack in the sheet it should be 15,155 kwh giving the range of 75km.

I have a 40 cell TS 160ah pack and i gives me more than 120km range.
My car takes about 150wh/km

@illuminatedda

Also more comments on the batterychart:
the "Total Power.." columns should be called "Total Energy ..." since it is the stored energy that is stated.

Best Regards
/Per Eklund


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## Tesseract (Sep 27, 2008)

illuminateddan - I agree with both of pm_dawn's statements. LFP cells don't suffer from Peukert effect (though they do age, which is supposed to manifest itself as an increase in internal resistance, so eventually I guess they will suffer something _like _Peukert effect).

Very useful chart - thanks for sharing!


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## illuminateddan (Dec 19, 2009)

*Re: Battery comparison chart V3!*

Hi guys,

Thanks so much for the comments. I have adjusted the chart to take these into account....
I'll leave the power rating titled power instead of energy as it is a wh and energy could be construed as something different such as joules per unit, etc



I have adjusted the 80% DoD to 70% Dod and up'd the cycles accordingly to manufacturer specs.
LiFePo4 Ah is now C3 from C20
Changed number of batteries to get >120v
Added Pack Lifetime cost per km
Thanks for all your input, keep it coming!

I have also put this document up on google docs as an editable file if you wish to tinker, download, edit or add stuff! Here is the link...

---removed due to sillyness---
 Please fill out the changes log when you edit stuff so we can keep track. Hopefully this chart will evolve and save some people some time!


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## TheConverted (Jun 20, 2009)

I could be wrong, but you may have stuffed up the km --> miles conversion, or vice versa on the Google link one.


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## illuminateddan (Dec 19, 2009)

Looks like people have been playing with the chart and bodged it . I have taken down the editable version, please send any changes or added data to me and I'll amend!

thanks!


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## ElectriCar (Jun 15, 2008)

Well this was a nice find. Thanks to PM Dawn. So considering all, the lithium pack will overall cost less per mile than the FLA pack I have now. That's what I've been looking for.


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## Robyj (May 28, 2008)

Illuminateddan: great job you did and are doing!


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## illuminateddan (Dec 19, 2009)

Thanks! haven't touched it for a while as I bought 38 x 90aha Thundersky cells. I might have to revisit it.....


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## austinraja (Sep 8, 2010)

Your idea is nice and this comparison chart is highly beneficial and simply superb


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## m38mike (Dec 27, 2008)

illuminateddan, 
what a great bit of research and analysis! Thank you for putting this all together. I've got one comment and one question. The comment is that you should probably put a date on this, as the cost of batt's is dated info.

The question is, have you considered making this spreadsheet automatically adjustable? perhaps there would be input blocks at the top to set the system voltage, or the conversion rate from AUD to USD or BP. The formulas would look to those master cells to find the value to use in the formula for each individual cell. 

Again NICE WORK!!


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## dtbaker (Jan 5, 2008)

ElectriCar said:


> Well this was a nice find. Thanks to PM Dawn. So considering all, the lithium pack will overall cost less per mile than the FLA pack I have now. That's what I've been looking for.



this is the same conclusion I have reached.... with the hope that Li delivers in excess of 3000 cycles, and you can buy cells from a retailer that actually delivers as promised. I ran thru a rough justification based on my known performance with FLA versus as similar pack of Li I could identify, and it looks to me like the cost per mile of actual use over battery life is significantly lower w/ Li.


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## Sunking (Aug 10, 2009)

Coley said:


> Gels are not just for UPS and stationary use.
> 
> They are used in many handicapped wheeled vehicles.


Well I can understand using a gel cell in a wheelchair where spills and leaks would be of a great concern, but for EV they are poor choices.

Gels have to be charged at a slow C/20 rate or lower, and have lower voltages. They cannot be equalized. Not good for EV applications especially if any regen braking is used. If over charged one single time or too fast the electrolyte dries out, cracks, and voids are created causing permanent damage which cannot be reversed.

AGM's are a lot better choice.


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## ryignacio (Oct 2, 2011)

I am new to this site. How do I find this chart?


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## GizmoEV (Nov 28, 2009)

ryignacio said:


> I am new to this site. How do I find this chart?


I see the chart in post #12. Keep in mind that the column labeled "Total Pack Power" should be "Total Pack Energy" because the unit is the Watt-hour, Wh, and that is an energy unit. The Watt is the unit for power.


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## GizmoEV (Nov 28, 2009)

*Re: Battery comparison chart V3!*



illuminateddan said:


> I'll leave the power rating titled power instead of energy as it is a wh and energy could be construed as something different such as joules per unit, etc


I know this is an old post but you really should use the correct term. The Wh is an energy unit *not* a unit of power. The Watt is the unit of power. Power multiplied by time is energy. The title should be "Total Pack Energy (Wh)." Note that the Watt is defined as a Joule/second and when multiplied by time, if that time is also in seconds, a Joule is the result which is energy. True a Watt-hour would be a Joule/second*hours but since there is a time unit in the denominator and the numerator the resulting number is a timeless unit which brings us right back to the energy unit, a "modified" Joule, as all that is left. The only difference is that we can no longer call it a Joule because it has been scaled by a factor of 1/3600.

Ok, this Physics teacher will get off his soap box now.


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