Ezee battery Vs Crystalyte Vs Cellman Lifepo4

[jerrysimon]

Jerry, how do you do to cycle only with 1.1ah or 2.3ah pack?

My Brompton is magic and has fairy dust in the frame

Seriously its pretty flat in Cambridge. My commute is 5.25 miles. I only use throttle to get me moving and assist up to 15mph and then switch it off and pedal. On still calm days I can average 17mph on the flat and easily hit 20mph plus if I want to. The Kojaks make the Brompton fly.

When its very windy I use throttle more, but I am always pedaling and rarely draw more than 5 amps and often less.

I am happy moving at an average 15mph.

Regards

Jerry

 

[cwah]

If you don't draw more than 5 amps, why don't you try the NMC cells?
2.2Ah 18650 Li-NiCoMn Cylindrical Battery Cells 1Box 96Pcs - BMSBATTERY

It has a much higher gravimetric density (193wh/kg for each cell without BMS and connection).

You can then have a safe pack that is either lighter or allowing you to reach greater distance.

 

[jerrysimon]

I never really knew they existed when I started and the A123s where more readily available at the time.

I don't see the point of switching now as I would have to change my bulk chargers for the 3.7v cells. I am also pretty sure those cells in one series strings would not be as reliable.

Ps Looking at specs you would have to put them two or three parallel strings for 5amp discharge and their cycle life is only 600!

Regards

Jerry

 

[Cyclezee]

Thanks for your reply, I am leaning towards your 14Ah battery for those very reasons...UK warranty and considerably lighter / smaller.

Can you tell me; in realistic use how much of the 14Ah capacity can you use before the voltage drops to an unacceptable level? Do you have any discharge / voltage comparison graphs or tests or anything so that I can compare to Lifepo4?

Hi Benjy,

When used with an eZee controllers 37v eZee batteries have a 31.5v cut off point to prevent deep discharge

 

[cwah]

I never really knew they existed when I started and the A123s where more readily available at the time.

I don't see the point of switching now as I would have to change my bulk chargers for the 3.7v cells. I am also pretty sure those cells in one series strings would not be as reliable.

Ps Looking at specs you would have to put them two or three parallel strings for 5amp discharge and their cycle life is only 600!

Regards

Jerry

Yeah, they are not as reliable, but that's a trade off between weight and cycle life.

As well as bike, I don't want to use disc brake because it adds an inconvenient additional weight even if it's more efficient.

For me, I plan to change battery every 2 years as better battery will be on the market over time. So from 500 cycles onward battery are fine for me.

 

[Cyclezee]

John, what's your battery exact chemistry? Is it NMC like BMSBattery?

Do you also have some specs such as the weight, wh/kg and number of cycle?

And of course, warranty can mean quite a lot of thing, to what % loss of the total capacity is covered by the warranty?

Because there is no way a battery would keep 100% of its initial capacity after 2 years.

Of course, if your warranty is 100% of its initial capacity after 2 years, I think it would be one of the best deal we have here

ps: My battery LiMn2O4 from conhismotor lost 1/3 of its capacity in 6 months. Very very bad deal.

Hi CWAH,

The majority of eZee batteries are Lithium Polymer with the exception of an 8.5Ah 38.4v FP Lithium Iron Phosphate.

eZee battery warranty is for 60% of the original capacity after 2 years, obviously manufacturers have to err on the pessimistic side when setting these figures. In reality the current generation of batteries are lasting longer, expectations are that the latest 20Ah VP will retain 60% for up to 5 years.

Weights for eZee FP (flat pack as supplied with eZee kits) are as follows:

38.4v 8.5Ah LiFePO4, 4.0 Kg.

37v 10Ah LiPo, 3.35 Kg.

37v 14Ah LiPo, 3.9 Kg.

48v 10Ah LiPo, 3.9 Kg.

Weights of eZee VP (vertical pack as supplied with eZee bikes) are

37v 8Ah LiPo, 2.8 Kg.

37v 10Ah LiPo 3.2 Kg.

37v 14Ah LiPo 3.8 Kg.

37v 20Ah LiPo 6.0 Kg.

 

[cwah]

Thanks for the info John. That really help to compare between battery.

If it is maybe a valuable information in your website for decision making.

In term of performance, your lipo seem very similar to the A123.