Pre-orders for LiFEPO4 packs

Please

drop us a line

if you would like to get on a waiting list for the new PHET LiFePO4 battery packs. We will only have a few packs come in on the first shipment, and we expect these will sell quickly based on pent up demand for this great new technology.

We will post pricing information here as soon as possible.

PHET LiFePO4 E-bike pack update

Here is a bit of additional information on the LiFePO4 packs we'll be carrying. These are packs made specifically for electric bikes by PHET (Phisiang Industries) that make the highest quality C-coated lithium iron phosphate (C-LiFePO4) cells available, based on the Phostech chemistry. For pictures of the packs, see

this blog post.

We have been testing the pack for about two weeks now, on our Xtracycle/Currie USPD high-power drive setup (600W+).

At an average 1C rate, the pack does appear to have the rated capacity of 7.5AH. This is just enough for a 15 mile trip with the loaded Xtracycle, in our moderately hilly area. When the pack voltage drops to about 25V, the battery management system will turn it off temporarily until voltage recovers.

The voltage curve on these is flat. They stay above 36V until about 7.1~7.2 AH of use. This is really nice in comparison to a lead acid, it allows use of nearly all the battery capacity. There is more information on the PHET batteries

here (this is a large PDF file)

.

The charger is built very solidly. We haven't measured the efficiency yet, but we will do so and post here.

Earlier, we posted that there was a current limit at 20A. Based on conversations with the manufacturer and our own further testing, this isn't true. Instead, the BMS system is set up so that if cell voltage drops below around 2.5V/cell (maybe a bit less) it cuts out power for a few seconds until the voltage recovers. The only time this seems to happen is when we are accelerating uphill on the Xtracycle/Currie/BMC setup, which can easily drain 30A. We've tested at a relatively constant 20A current for 1 minute or more, and it doesn't seem to cut out.

About the only negative so far about this pack is that the plastic handle on the end is a bit flimsy. It is solid enough for carrying the battery, but we cracked ours when we dropped the pack on it from a few inches height. A bit of duct tape fixed that right up!

All in all, this is a solid performing pack! We don't use our NiMH or SLA packs anymore (

drop us a line

if you want to buy a lightly used SLA or NiMH pack in a nice case).

Folding bikes!

Folding bikes are a great niche for those who do multi-modal transport, such as combining bike/bus or bike/train trips. They're also great for those who travel a lot by airplane and want to take a bike along, without paying baggage fees. We did a two-week long cycle trip in Italy on folding bikes recently, and we had a lot of fun! And the bikes were easy to take on the train with us to get from one place to the next (if it was too far to practically bike). A couple pictures from our tour of Volterra on the bikes are shown below.

It looks like we'll be carrying a brand new style of folding bike, that folds in 1 second to a neat little package! We will be evaluating the bike for durability and quality. As soon as we've had a good look at it, we'll post some pictures here.

New LiFePO4 batteries!

Batteries are the lynchpin of an electric assist (or Pedelec) bike. We're excited to now be testing a new Lithium Ion Phosphate pack that is the slickest one we've seen in this new chemistry. For more information on battery chemistries, have a look at our

FAQ

. The short story is that these batteries are light, safe, they last a very long time, and they are environmentally friendly. They have a big upfront cost, but they will more than pay for themselves in trouble free operation for many years to come. For those still using a sealed lead acid pack, these batteries are so much nicer (I hate putting the SLA's on my bike now). Our 36V lead acid pack weighs over 30 lbs. The new 36V Li-Fe-PO4 weighs 9 lbs. For those running 24V systems, we'll have a 24V pack too.

One thing we've discovered is that these are limited to about 20A, or about 720 Watts for the 36V version

.

[See new blog entry]

. It is a self-resetting circuit that cuts out power for about 10 seconds. This is much better than a fuse. For most systems (Crystalyte 400 series, Goldenmotor, Currie USPD, Lashout, etc), this shouldn't be a problem, but for the really high power hubs (e.g. Crystalyte 5000 series/Phoenix) the limit might be too low.

Some pictures are below. We may be taking pre-orders at a discount once we do further testing and set the final price. Please

contact us

if you are interested, and we'll let you know when the batteries will be ready to roll.

Side view showing pack and rear rack mount

Front view, pack plugged into mount

Front view of pack with charging port and discharge port