Jimbo397

Hi Everyone
I am thinking of purchasing eZee Bike Conversion Kit, rear wheel.
https://ebikes.ca/store/store_ezee.php
And upgrading the battery to 37V 14Ah Polymer pack. Do I have cause for concern about this battery exploding or starting a fire?
Seem I have read a lot about this type of battery burning up, but can’t see any reputable business selling them if that was the case.
How does the 37V 14Ah Polymer pack, compare to the new The 48V 8Ah lithium battery that they recently started selling. https://ebikes.ca/index.shtml

morph999 

the 48v 8AH battery = 384 wh

37v 14AH = 518 wh

The 8 AH battery will give you less range but more speed because it's 48v. You could probably get 16 miles without pedaling with the 8 AH battery. With the 14 AH, you could probably get about 25 miles without pedaling. The polymer is more dangerous. If you have a barbecue grill that you can charge it in outside then it might be okay to go with the polymer. I have lifepo4 and it's very safe but I still never charge the battery without being within ear shot of it. If 16 miles is okay for you, then go ahead and go for the lifepo4 pack. Also realize that the Ezee kit is mainly for getting up hills and it's a great motor for pedaling because it freewheels so nicely. You aren't getting the ezee for speed because it probably maxes out at around 22 mph at 48v and probably 18 mph at 37v. It's a great all -around motor but just don't think you'll be going 30 mph on it.

morph999 

did you see the option at the bottom to take the battery off of the kit...it says - $470. Then you could buy the battery somewhere else if you found a better battery pack.

nwmtnbkr

Given your question, I would guess that you saw my comments and the You Tube video in this thread. https://www.bikeforums.net/showthread.php?658028-Where-do-you-buy-LiFePO4-batteries-(Non-Ping)-looking-for-Higher-C-and-good-quality. I will say this again, LIPOLY batteries, which have a polymer cathode, are the most volatile of the Lithium chemistries. They are not the standard battery provided with the Ezee kits (as ebikes.ca notes on their web page, the standard battery provided is Li-ION with a Mangenese Oxide cathode--Li-ION have either Cobalt Oxide or Mangenese Oxide as the cathode). Li-ION, although not as volatile as LIPOLY, is subject to thermal runaway (fire). LIFEPO4, which has Iron Phosphate as its cathode is the most stable and safest, however, it can't pack the high C ratings of LIPOLY and can't fit extremely dense energy into the very small form factors that Li-ION does.

Would merchants sell LIPOLY knowing its dangers? Yes. That type of Lithium battery is sold online, mainly to RC enthusiasts. Should you have concerns about it? Yes, you need to be careful handling it and charging it. Should you choose it? Well that's your call. However, you know LIFEPO4 is safe so if safety's your main concern, that should be your choice. Look at liability waivers you may be asked to sign, too. It's not uncommon for you to be asked to click on a liability waiver when making a purchase online.

Jimbo397

Thanks for the reply, I would like something that would give me more speed then what you mentioned here, an greater range would be also be nice.
I don't mind some peddling and am looking to build a quality bike that will be good for a few years to come.
I know that I can always put a different battery on that will give me more speed & range, such as a 48V 20AH.
But what motor to choose, this is the part that I am lacking knowledge in.
Any recommendation are greatly appreciated.

morph999 

If you want speed, the crystalyte 5303 is probably the way to go and it will carry you up most small hills. I get to 30 mph on just 36v. With 45v the other day and a wind at my back, I got up 37 mph. If you want the 5303 and 35 amp controller like I have, you'll need a battery that can handle 2C. Something like Headways or A123's. That's getting really expensive, though. I'm using Thundersky's on mine but I only use 50 % of the battery but if you want to do that, that's an option too.

My total bike cost... $750 for motor and controller + $390 for the 36v20AH thundersky = about $1150 . That includes shipping and handling. I got it from ebikes.ca. I love it. It's so awesome. I ride down the bike paths at 30 mph. Or you could get a BMS for the Thundersky's which is probably an extra $100 and then you could use more of the battery probably. Going fast is pretty expensive. That's just the way it is.

Or another option, if you want to go with LIPO batteries. They handle high C rates. Just make sure you charge them outside in your barbecue grill.

Or you could go with these Turnigy LIFEPO4 packs. Get 8 of them for a 40v 9AH pack. 40v would probably get you to something like 32 mph on the 5303. 8 of them would be $320. They handle high C rates.

https://www.hobbycity.com/hobbycity/s...C_LiFePo4_Pack

morph999 

I just looked up the max speed for Ezee on ebikes.ca and they say at 48v, it goes 24 mph. Ezee motor is made more for climbing hills and also for people who like to pedal or like the ability to pedal freely without any cogging. The 5303 is almost like a moped. Not quite the acceleration of a moped but you can easily use it all day without feeling any need to pedal because it accelerates pretty good for an e-bike. If you put about 100v on a 5303, it would be faster than a moped and probably accelerate faster than one.