# Battery choices



## Ziggythewiz (May 16, 2010)

The same chemistry will have the same voltage range. Any numerical differences are mostly different levels of being conservative with the cells.

Your location vs that of the battery distributors is a big factor affecting price and availability.

Other things I look at are cycle life and reputation.


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## EVEngineeer (Apr 11, 2012)

Hello, I am working on a chart in the wiki that should help your decision, but it is not completed. Check back daily to see updates. Please help me out if you can. http://www.diyelectriccar.com/forums/showthread.php?t=81463


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## dsscrusher (Apr 3, 2008)

I did a little spreadsheet and I have it on my laptop at home. I will post what I found.


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## dsscrusher (Apr 3, 2008)

I will probably do a road trip to the US to pick up batteries and the motor. Both are available in stock at some places. I am smack dab in the center of the continent so shipping is big. I may have a connection with my uncle who works for an airline and get air ship cheap. Even 300 lbs of lithium. Maybe direct from China. Time will tell.


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## skooler (Mar 26, 2011)

Cant go wrong with CALB or Sinopoly. I cant comment on GBS.

Be wary of Winston, nothing wrong with the cells but apparently they are about to stop trading.

I'd stay away from best-go, there's a thread on here somewhere about how terrible their customer service is!

As for HiPower, nothing wrong but they are larger and heavier than the CALB/sinopoly alternatives and are more or less the same price.

Hope this helps.

Cheers,

Mike


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## dougingraham (Jul 26, 2011)

I have 60 of the GBS 100AH cells and they are good cells. I particularly like the 4 point terminal posts and the supplied covers. They also have little alignment nubs so they lego together well. However, if I was buying today I would get the 100AH CALB CA cells because of the tests I have seen performed on this particular chemistry cell. They just seem to stand out above the rest in performance both delivering higher currents and low temp performance.

I would not base any decision on the published spec sheets. For the most part these just seem to have very generic information that in some cases appears to be copied from other brands.

In particular I would not try to make battery boxes a tight fit based on the spec sheet measurements. Get the batteries and arrange them the way you want and then measure.

Have fun with your conversion!


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## piotrsko (Dec 9, 2007)

don't think they will air ship 300 lbs of lithium, better check first.


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## Elithion (Oct 6, 2009)

dsscrusher said:


> I will probably do a road trip to the US .... I am smack dab in the center of the continent.


In the Mid West there's Electric Car Company in Utah (BestGo cells, but they don't stock, so you would have to pre-order and pre-pay), and Evolve Electrics in Colorado (they stock Sinopoly cells). Both companies also sell motors and BMSs.


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## Ziggythewiz (May 16, 2010)

*Re: Lots of strong worthless opinions...*

Do you have facts and data related to "customer service"?


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## skooler (Mar 26, 2011)

*Re: Lots of strong worthless opinions...*



kennybobby said:


> about Li batteries from a guy using lead acid...? Over the past two weeks i have been doing discharge testing of 44 Bestgo 100 Ah prismatics. Every one of them easily measured over 100 Ah-- actually closer to 105 Ah. Let the facts and data indicate which are good batteries, not opinions based upon anecdotes.


Just because I am yet to use them in my conversion doesn't mean that I have not used them for other applications and spent considerable time on research and testing.

On the bestgo side of things, my comment was on customer service and not the quality of the cells:

http://www.diyelectriccar.com/forums/showthread.php?t=75031

http://www.diyelectriccar.com/forums/showthread.php/bestgo-crap-80782.html


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## MemphisPapa (Feb 16, 2012)

*Re: Lots of strong worthless opinions...*



skooler said:


> Just because I am yet to use them in my conversion doesn't mean that I have not used them for other applications and spent considerable time on research and testing.
> 
> On the bestgo side of things, my comment was on customer service and not the quality of the cells:
> 
> ...


I bought 32 of the160Ah version of BestGo batteries. They eventually got to me, but with a lot of emails and eventually a charge back of my credit card to push delivery. As far as quality, I can't say yet. I received them at about 2.88V. After a couple attempts at balancing them in parallel, I still have a couple high cells with a 0.015V difference. Maybe that is good enough for you or maybe the 100Ah cells are better. I waited for four months for delivery after I had paid in full. Don't get me started on the BestGo charger disaster.
Maybe I am the least lucky guy on the planet, but I didn't get any customer service from BestGo and I'm still waiting for a refund from the electric car company for the past month.


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## xmbaleaf (Dec 13, 2012)

*Re: Lots of strong worthless opinions...*



MemphisPapa said:


> I bought 32 of the160Ah version of BestGo batteries. They eventually got to me, but with a lot of emails and eventually a charge back of my credit card to push delivery. As far as quality, I can't say yet. I received them at about 2.88V. After a couple attempts at balancing them in parallel, I still have a couple high cells with a 0.015V difference. Maybe that is good enough for you or maybe the 100Ah cells are better. I waited for four months for delivery after I had paid in full. Don't get me started on the BestGo charger disaster.
> Maybe I am the least lucky guy on the planet, but I didn't get any customer service from BestGo and I'm still waiting for a refund from the electric car company for the past month.


Four monthes? why did you wait for so long,? it is a crazy delivery day.


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## agniusm (Apr 30, 2012)

Hello. Did anybody tested Liyuan Supercapacitor cells? They have 100AH cell HPC3R2101. Internal resistance .9, max discharge 15C, cycle life more than 2500 cycles, weight - 2.51kg.
Here are some tests done with 20ah cell, they say that discharge is close to A123 prismatic if not better:
Google translation
I wander what they cost
Here is 336V 120AH battery pack: http://cyly.en.alibaba.com/product/669066499-212935359/336V_120Ah_Li_ion_battery_packs_supercapacitor_LiFePO4_battery_.html


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## Elithion (Oct 6, 2009)

agniusm said:


> Liyuan Supercapacitor cells?
> 
> Here are some tests done with 20ah cell


That is truly "impedance" (at 1 kHz). It's totally meaningless to us users, as we use batteries at DC, not 1 kHz. While the AC impedance is about 1.6 mOhm, the DC resistance is actually about 2.9 mOhm. 

How does that compare, as far as power handling? It puts it smack in the middle of the range of all the cells and batteries we analyzed.








You'll note that the power handling of these cells is twice as good as for Sinopoly / CALB / Winston prismatic cells.



agniusm said:


> discharge is close to A123 prismatic if not betterl


Which is not saying much: the A123 20 Ah pouch cell is worse than average, as far as power handling is concerned, despite all the marketing hoopla.



agniusm said:


> I wander what they cost


About 2 $ / Ah from Electric Car Parts Company

That's almost twice as much as standard prismatic cells. However, that is in line with the price of other high power cells.


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## agniusm (Apr 30, 2012)

Elithion said:


> That is truly "impedance" (at 1 kHz). It's totally meaningless to us users, as we use batteries at DC, not 1 kHz. While the AC impedance is about 1.6 mOhm, the DC resistance is actually about 2.9 mOhm.
> 
> How does that compare, as far as power handling? It puts it smack in the middle of the range of all the cells and batteries we analyzed.
> 
> ...


Nice graph but that shows nothing either.
There must be a lot more than how quick they discharge: power to weight ratio, cycle life vs cost per ah etc etc. That graph was perhaps meant for personal use as it would not help anyone choosing cell for hes/her custom battery pack. And it does not mention what capacity Liyuan cell discharged in
65s.


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## Elithion (Oct 6, 2009)

agniusm said:


> There must be a lot more than how quick they discharge.


Yes, absolutely! And all that other information is indeed available and published. The Short Discharge Time characteristic is filling a hole left by the specs: how good a cell is for high power applications. 

You're totally right: I wouldn't select a cell based on Short Discharge Time alone. For example, I chose Enerdel cells for a high power traction pack, even though Kokam and EiG make better cells, because the Enerdel cells were a better value, and were readily available.




agniusm said:


> And it does not mention what capacity Liyuan cell discharged in 65s.


They WERE NOT discharged in 65 s! That would be madness! 
Short Discharge Time is a _mathematically derived _characteristic, based on physically measurable parameters. What you may not realize is that one of the beauties of Short Discharge Time is that it is independent of cell capacity! The 65 s Short Discharge Time for the Liyuan cell is the same for the 20 Ah cells as for the 60 Ah cells, because they all use the same technology. Neat, huh?


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## Ziggythewiz (May 16, 2010)

Elithion said:


> They WERE NOT discharged in 65 s! That would be madness!
> Short Discharge Time is a _mathematically derived _characteristic, based on physically measurable parameters. What you may not realize is that one of the beauties of Short Discharge Time is that it is independent of cell capacity! The 65 s Short Discharge Time for the Liyuan cell is the same for the 20 Ah cells as for the 60 Ah cells, because they all use the same technology. Neat, huh?


If your Short Discharge Time does not mean the time it was discharged in you should probably explain how you're deriving it.


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## agniusm (Apr 30, 2012)

I guess they discharging is tied to C rate, say 20ah 5C would be 100A load and 60AH cell - 300A at same C load in which case they would take same time to discharge different capacity?!


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## Elithion (Oct 6, 2009)

Ziggythewiz said:


> If your Short Discharge Time does not mean the time it was discharged in you should probably explain how you're deriving it.


Please see this post.


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## kerrymann (Feb 17, 2011)

MemphisPapa said:


> I bought 32 of the160Ah version of BestGo batteries. They eventually got to me, but with a lot of emails and eventually a charge back of my credit card to push delivery. As far as quality, I can't say yet. I received them at about 2.88V. After a couple attempts at balancing them in parallel, I still have a couple high cells with a 0.015V difference. Maybe that is good enough for you or maybe the 100Ah cells are better. I waited for four months for delivery after I had paid in full. Don't get me started on the BestGo charger disaster.
> Maybe I am the least lucky guy on the planet, but I didn't get any customer service from BestGo and I'm still waiting for a refund from the electric car company for the past month.


I have to second your experience. I recently gave electric car company a second chance after the debacle of buying my Miata motor adapter from them (promised 10 days, over 10 weeks and didn't work). They had a great price on some cells so I ordered through paypal to cover my purchase. After sending them almost $3000 and almost 2 weeks of emailing them not getting any response. Finally I get a email from Carl saying it was a price mistake (fair enough) and that he had refunded my money (but they hadn't). Luckily paypal has excellent buyer protection.

On the other hand, Evolve is great and everything I have ordered from Justin (DC-DC, BMS) has been shipped fast and arrived as just described. I would recommend them without hesitation.


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