Battery Chemistires for the average Joe

[KiM]

Battery Types explained for the average Joe

My sparring partner over at Endless Sphere forums made a cracker of a post i thought had to be shared with Motoredbike.com member's... the different battery chemistry's are often confusing for those new to the e-bike scene, so here's 'ol Hyenas run down on it all for
the average Joe.

You know you want to!

Someone was asking me about the different ebike battery types the other day, so I'll post it here in simple terms


Hyena's guide to ebike battery technology (if they were women)

SLA

This is the fat girl at school. She ate all the pies and if you have to put her on the back of your bike you'll know all about the extra weight. She may break your frame if you're rough with her. That said she'll put out because she doesn't know when someone will show interest in her again. Expect some nasty sagging, and while she might be able to travel 20 miles at walking pace, don't expect her to go that far if you make her run. Expect her heart to give out after a year.

2-3C LiFePO4

This is common plain Jane from accounts. She'll cost you a bit more than SLA the Hutt but you won't break your back lugging her around and she won't drop dead after a year of you exercising her. She does have asthma though so while she'll whip along the flat OK don't expect her sprint off the line or blaze up steep hills.

6-10C LiFePO4

If wheezy Jane from accounts isn't performing well enough for you meet Helga. Part Barvarian, part Viking she can run just as fast as Jane but has bigger muscles to flex. Wanna get off the line quick or up that steep hill ? She'll throw you over her shoulder and carry you up. The trade off is she isn't exactly slight... mmmm, chunky

20-50C Lipo

Meet Kara Kent. She's hot with a fit athletic body but for her small size and weight her power is out of this world. She can easily lift 20x her weight, be super fast and in the RC world she can fly. Be warned, if you get on the wrong side of her she'll melt your skin off with her heat vision. She's a little higher maintenance than Helga, but isnt she worth it ?!

I hope the masses enjoy their lifepo4, I'm happy with lipo between my legs :mrgreen:

Sums it up beautifully.... Top job there Jay... LiPO for the FTW

KiM

 

[deacon]

very informative.. and entertaining which always helps. Also it makes a point about the 2-3 c i noticed while trying to make the nimh work. The nimh i was working with did not have any beef at all for start up or hill climbing. I'm glad to see that written down somewhere.

 

[zean]

Excuse me KiM, with all due respect can I disagree? I appreciate you sharing your knowledge. I'm thinking about the growth of this industry. When I communicate about motorized bicycles to people, men and women both show an equal interest, perhaps the women ask me more questions than the men. Sometimes I refer them to this website for information. This type of analogy will turn the women away from the website and maybe the hobby. This industry can grow into an everyday part of life only if it is accepted by men and women both. Battery chemistry could be one of the factors that help pull America out of the little bit of economic funk we have going on. I found your information relevant and interesting. Thankyou.

 

[KiM]

Excuse me KiM, with all due respect can I disagree?

Certainly can that's the great thing about forums, people have different opinions on different matters and can voice them... I suggest you don't direct woman to this thread and/or endless sphere where this exact post exists in several threads.

KiM

EDIT: haha ... If you have problems with this though i suggest you take it up with my buddy Hyena at Hyena Electric Bikes and he can run your lady friends through the technical aspects of battery chemistry minus the wiminez

 

[pinjas]

I've been wondering, is there anything wrong with using deep cycle AGM or gel batteries on electric bikes? I understand that weight is a concern, but I've been considering cost as an issue as well.

I was thinking of the idea of using a 500 watt 48v brushless DC motor. To power it, I was thinking I would daisy chain 8 small AGM batteries. Obviously, 8 times 6 is 48. But beyond that, it seems like lower voltage batteries yield greater amp hours at similar weights. Maybe I am missing something, but I have mathematics to support this claim.
Tempest Batteries - Replacement Batteries - www.batteryspec.com

I look to this page, and I see 'TR12-6'. 4.56(weight of the battery)x8(need 8 batteries to get to 48 volts)=36.48lbs.
This setup would have 96ah(amp hours). 12ah per battery.

I see 'TR12-12F', 7.96x4(need 4 batteries to get to 48 volts)= 31.84lbs. This setup would have 48ah, 12ah per battery.

Daisy chaining batteries is very good? The 8 battery setup costs 3 dollars less but has twice as much amp hours. Is there some sort of hard core negative to daisy chaining batteries? Am I entirely missing something? Please feel free to correct me. I wonder if this is true with all kinds of batteries.

 

[KiM]

Of course its possible its a question of why the heck you would want to, its a bad move, the T12-6 you mention is a 6v 12ah battery, if you series 8 of them you will get your 48v but it will be 12ah not 96ah as you state above. If you paralleled the 8 packs you would get 96ah but then on 12v... Save your money for a suitable lithium pack for the above stated 500watt setup, in the long run they work out cheaper, they last upward of 2000 charges opposed to ~500 for Lead acid or in this case absorbed glass matt, they are a poor option for an e-bike in every way.

KiM

 

[zean]

Hi Kim. I see. In a series circuit the voltage varies and the current stays the same. In a parallel circuit the current varies and the voltage remains constant. The information about lithium, the whole deal is very interesting. Thankyou.

 

[wheelbender6]

I'm lousy at chemistry and electromagnetism. Does "2-3C" mean 2 or three cells? I am accustomed to determining range by the amp hour rating.

 

[corgi1]

Excuse me KiM, with all due respect can I disagree? I appreciate you sharing your knowledge. I'm thinking about the growth of this industry. When I communicate about motorized bicycles to people, men and women both show an equal interest, perhaps the women ask me more questions than the men. Sometimes I refer them to this website for information. This type of analogy will turn the women away from the website and maybe the hobby. This industry can grow into an everyday part of life only if it is accepted by men and women both. Battery chemistry could be one of the factors that help pull America out of the little bit of economic funk we have going on. I found your information relevant and interesting. Thankyou.

Could you make up one w/males in the analogy and pics and direct the women to that,if they(the women, ) are fair and openminded and they (both analogys)were both posted,i would see no problem,equal rights?

 

[zean]

I didn't mean to come off the wall. Sorry I brought it up. In the future I'll restrict my coments and questions to design, style and mechanical problems of motorized bicycles. "You haul sixteen tons and what do you get? One day older and deeper in debt." Tennesee Earnie Ford.

 

[Thud]

Wheelbender,
here is the explanation of "c" rates as we use the term. It is form CBP's web site:

we use the designation 10C etc to mean how much a cell or pack can discharge in amps. C always equals the capacity of a cell or pack. For example. Let use a PQ31003S pack rated for 12C. In this case C=3100mah. the number before the "C" is the multiplier. so 12 x 3100 = 37200mah. to get amps we simply divide by 1000. 37200/1000 = 37.2 amps. 1000mah = 1amp.

So for the above pack (PQ31003S) rated @ 12c we now know the max discharge rating is 37.2 amps.

Another example: a 20C 1800mah 3S pack. What is its max rating? 20 x 1800 = 36000. 36000mah = 36000/1000 = 36amps. So the 1800 3s pack @ 20c has a max rating of 36amps.

so when ever you see a C rating take the number before the letter "C" and multiply the packs capacity by it. That is it. To get amps from your new number simply divide it by 1000mah.