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-   -   Sticky thread for batteries? (http://www.bikeforums.net/electric-bikes/370920-sticky-thread-batteries.html)

mikek3 11-25-10 11:53 AM

Cold weather battery
 
Well I answered my own question. The cold does seem to affect the battery. If you see my last post the battery was being throttled by the BMS I think. During the last week the weather turned warmer and I had no problems. Yesterday the temperature dropped below -3 C and the same problem occurred. It he battery is left outside all day at work in these temperatures it seems to start cutting back to half power on the way home. I guess the solution will be to take it in to my office during the day when it is this cold. Or stop biking.

kauaikit 11-30-10 07:50 PM

Hello falconev....what's your solution to replacing the 3 SLA batteries in a '00 EGV 36V Global bike? I'm assuming your putting, & wiring them in the same box/charger, with an added connector to charge them?

Does the stock controller need to be updated too?

Price?

tpreitzel 12-07-10 02:22 AM

Axion has been quietly working since 2003 on another proprietary version of lead acid chemistry called PbC:

http://www.axionpower.com/profiles/i...1&s=0&ID=10299

Axion's product has been undergoing real world testing for at least 5 years so it's not simply a laboratory experiment.

I'll guarantee you that lead acid isn't going away as the infrastructure is simply gigantic and well established worldwide. Lithium reserves are limited so we already know that lithium based chemistry is simply transitional to another type of chemistry, e.g. zinc-air.

Also do you know that carbon fiber can act as a battery? Yeah, that's right, we'll likely see structural components consisting of carbon fiber acting as batteries as well... unbelievable where battery technology is headed...

DarthSensate 12-08-10 09:37 AM

Quote:

Originally Posted by tpreitzel (Post 11897092)
I'll guarantee you that lead acid isn't going away as the infrastructure is simply gigantic and well established worldwide. Lithium reserves are limited so we already know that lithium based chemistry is simply transitional to another type of chemistry, e.g. zinc-air.

This is something that a lot of people in the ebikes and EV supporters, as well as the nay-sayers, fail to think about a lot. Lead may be toxic but so is lithium. The infrastructure for lead based batteries is very well established and thus much more eco-friendly simply by the fact that it is easy to recycle lead batteries.

Lithium is also a rare-earth metal and therefore not going to get cheaper as it is more and more widely adopted. The last thing the world needs is another resource crunch like with oil reserves/production.

I continue to be hopeful for lead technologies and the zinc based compounds sound like a good idea as well. I'm pretty sure Zinc is about as non-toxic as you can hope for. Zinc technology isn't coming real fast though, secondary Zinc batteries are horribly inefficient to re-charge... right now.

As for the carbon-nanotubes, I think they are an excellent potential storage medium but I worry about the potential for catastrophic failure for a cell based on these. The available discharge rate for nanotubes is more similar to capacitors than batteries. Of course that changes as lead based battery energy density and current delivery issues are solved. Seeing a capacitor explode and seeing an old lead-acid battery explode are pretty scary when you consider packing more and more amp-hours into a motor vehicle.

When the energy density and re-charging issues are solved, there will be a safety issues to consider. As with safety mechanisms at gas stations and collision safety designs in gas tanks, high amperage charging stations at home or at pumping stations and battery cell arrays in vehicles will have to be carefully designed.

sunnyday 12-10-10 02:29 PM

I predict at least a average 10% drop in prices on 36-48 volt lipo packs over the next 12 months. I think it will be common place to see 48 volt- 20Ah lipo packs selling for $400- $500 ranges by late 2011. Even Right now, if you shop on ebay, I have seen those prices with no reserve auctions, if you are willing to buy direct from china and wait about 2-3 weeks to get your item. Of course a good charger is the other half of the equation...a great battery pack may turn into a dud if you are using a low grade charger that cannot equalize the individual cells.

sunnyday 12-10-10 02:33 PM

I remember many years ago when lipos hit the scenes in the R/C hobby market...a normal Nimh 9.6 volt 1200 Mah battery pack was about $29.00...but a lipo pack near the same ratings was around $ 80.....it took a few years, but now that same $80 lipo pack can be had for $ 19.99 ...

we will start seeing a simliar price drop with the larger voltage/Ah lipo packs used for bikes.,,,,they may not come down 70% in price like the smaller lipo packs did..but they will come down. I will bet on it.

DarthSensate 04-26-11 02:18 PM

For what it's worth, EETimes just printed an article in April 4th edition projecting $/kWh will be $300 by 2018.
(EE Times, "A Million EVs", April 4th 2011)

donob08 04-26-11 04:02 PM

$300 by 2018???
 
"DarthSensate

For what it's worth, EETimes just printed an article in April 4th edition projecting $/kWh will be $300 by 2018.
(EE Times, "A Million EVs", April 4th 2011) "

It should be pointed out that this article refers to batteries for cars not bikes. The current has to be ~ 100 Amps+ not 20 Amps like a bicycle.

jethro56 04-26-11 04:45 PM

I paid $450/kWh a month ago. I'll wager it's $350/kWh next spring.

Sangesf 04-26-11 05:25 PM

$450 per kwh?
(I'm hoping new)
Where did you get it so cheap?

edcastrovalley 04-26-11 08:26 PM

It's got to be lipo. For what I paid for my lipo it would cost me $447.46 for 1 kwh of the stuff. I even got free shipping on one of my orders.

Sangesf 04-27-11 01:46 AM

Yeah, ok, Lipo..
But how much (extra) does it cost for the charger, power supply, cell logs and miscellaneous wiring.. *That has to be included in the cost..

I can get 1kw for $529, with Charger and BMS, including the shipping.*
(LiFePo4)

edcastrovalley 04-27-11 10:07 AM

Ok Sangesf, you got me there. I paid $121 for my charger but, I smoked that one. In the meantime I'm charging off my welder until I my charger gets back from warranty repairs. I would advise staying away from the SF East Bay in the meantime. :lol:

I also got close to $100 invested in Andersen connectors and the crimper. The crimper is schweet! If anyone wants to crimp something stop on by. It does the 15/30/45 amp connectors.

jethro56 04-27-11 12:08 PM

For sure LIPO is not ready for prime time and the charger is more expensive I got $225 invested. Let's not do the LIPO versus the world thing. I respect the advantages of the different chemistry's. LIPO was just too cool for a geek like me.

jethro56 04-27-11 12:09 PM

Quote:

Originally Posted by edcastrovalley (Post 12563323)
Ok Sangesf, you got me there. I paid $121 for my charger but, I smoked that one. In the meantime I'm charging off my welder until I my charger gets back from warranty repairs. I would advise staying away from the SF East Bay in the meantime. :lol:

I also got close to $100 invested in Andersen connectors and the crimper. The crimper is schweet! If anyone wants to crimp something stop on by. It does the 15/30/45 amp connectors.

+1

Sangesf 04-27-11 12:23 PM

Don't get me wrong, LiPo rocks!
It's just not a newbie thing...
If you like to tinker and are careful, Lipo, will give you years of wonderful power.
(The initial expense of charger and cables can be worth it, when you start adding parallel groups of the same series strings)

For newbies I suggest Ping LiFePo4 batteries (OR if you're tight on budget and have a month or so to wait, a VPower LiFePo4 battery (with charger, BMS)) is good too..

Nowadays, Lead just isn't really a viable option anymore because of weight to power ratio.

jethro56 04-27-11 01:23 PM

I actually ordered a 48V LifePo4 battery. After waiting a month, getting assuances that this was normal.I was finally told that my battery was shipped to another customer. I was told don't worry we'll get you one in another 3-4 weeks. I asked for and got refunded. Shortly afterward (days) the supplier took LifePo4 batteries off the Website. Somehow I think I would have never recieved the battery. My LIPO's and Hyperion 1420i arrived 5 days after ordering. I was riding my bike that day.

Sangesf 04-27-11 02:50 PM

How about telling us who the lifepo4 supplier was so that we can avoid them?

jethro56 04-27-11 03:06 PM

He did refund me and isn't selling any until he finds a better vendor. So... he gets a pass.

tpreitzel 07-09-11 11:23 PM

The following article on the availability of rare earth minerals categorically states (no reference) that China is strategically manipulating availability of rare earth minerals causing steep increases in cost. The article mainly discusses the discovery of huge new deposits of rare earth minerals in the Pacific Ocean east and west of Hawaii in international waters. Is the price of Lithium-based batteries increasing?

"China, which accounts for 97 percent of global rare earth supplies, has been tightening trade in the strategic metals, sparking an explosion in prices."


http://uk.reuters.com/article/2011/0...76300320110705

coolio 07-19-11 07:49 PM

Quote:

Originally Posted by Sangesf (Post 12563962)
For newbies I suggest Ping LiFePo4 batteries (OR if you're tight on budget and have a month or so to wait, a VPower LiFePo4 battery (with charger, BMS)) is good too..

Right now, Ping is beating Vpower for a 36v 15ah Lifepo4 battery by about $200 bucks w/shipping, which I'm considering.

spookee 08-29-11 08:32 PM

Battery Life Question
 
Hey, Newbee here with a question. I have a Diamondback mountain bike that was converted with a 36V Wilderness kit using a 36V Lithium Ion battery. My commute is about 10 miles, mostly downhill to work and mostly (you guessed it) uphill on the way home. When I first started riding I needed to use the motor most of the way home, but over time I've gotten in better shape and needed it less and less. Now I only use it for this last really steep hill of about 1/3 of a mile that I could never make it up without help. I'm sure I could make it up this hill many times on one charge. So is it better charge fully after every trip or charge once every 10 or so trips? Or does it matter as far as battery life goes? Thanks Much!

Spookee

Eclu Lardbut 08-30-11 05:11 AM

Many shallow small charges are better for a lithium battery than few large deep discharges. In your case it would probably be a waste of effort to charge it every night, but perhaps every few days might be good.

nimbuzz 09-04-11 12:32 AM

Spook, I'd charge it every night or two or three but once a month I'd take it down further = 75% drained to 'cycle' it.

SeizeTech 09-05-11 06:56 AM

One thing worth considering is the quality of your BMS board. If you BMS board is a good one, it will balance your battery cells during recharge.
If your BMS does not balance your battery cells, then your battery pack would go out of balance more easily with a deep cycle....ie several shallow cycles would be better.


Hmmm......come to thing of it, even if my BMS balanced the cells, several shallow cycles would be more desireable.

Oh well, i wont go back and change anything in this post, i think it still has some value even if it isnt completely acurate.


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