Thursday, May 31, 2012

Considerations for a replacement Tidalforce battery

I'm very fortunate with my 4 Tidalforce bikes in that I have been able to locate and use relatively new or only slightly used Tidalforce hub batteries with my TF bikes! Of course, this will change as the current front batteries start dying or losing capacity. Hopefully, this won't be any time soon!

In thinking about upgrading or replacing the front hub battery, here are the key things I"m trying to keep in mind.

The battery needs to be able to handle the load the Tidalforce bike needs. If you have a 750 watt Tidalforce bike, then with a quick calculation, (750W/36V= 20.83Amps) you'll need a battery that can put out about 20 amps continuously. This is sometimes difficult to find since most battery manufacturers (especially the Chinese ones), don't really publicize the maximum discharge rate (known as the "C") of their batteries.

When looking at a battery, the "C" rate is equal to the capacity of the battery. If your battery is rated at 10Ah, then 1C would be 10A. So using this rule, you will need a 10Ah battery that can output 2C. If you have a 20Ah battery, then it must be able to output 1C, etc.

If you have a Tidalforce 1,000 watt motor, then you'll need a battery that can output 27.7 Amps maximum since that is what the motor will draw. (1,000W/36V=27.77A). If you have a 10Ah battery then you'll need one that can output 2.7C.

Also, the controller that is located in the Tidalforce motor housing is a current based controller and not a voltage based one.

If you're trying to maximize the speed of the bike, then you should use a battery that can be customized to be higher than the standard 36V nominal rating of most bike batteries. Remember that higher voltage means higher speed. Larry H. known as Deerfencer1 on the Tidalforce forum has proven this. He is able to get higher than average speeds with his X powered S-750 named "Uma" because his LiPO batteries don't sag very much from their nominal voltage because they have very high C ratings.

LiPO batteries designed primarily for RC flying and driving toys are designed to have very high C rates. Typically they can be 20C to 30C for an 7.4-18V battery. This translates into very high current output capabilities. An 18V battery putting out 30C equals 540A! Of course that battery won't last for very long, but it will definitely give you all it's got in a very short amount of time! Of course, I don't recommend you run the batteries down by drawing such high current from them!

However, if they can truly deliver these amazing currents, then they must have very low internal resistance which means that the batteries will not heat up much when used heavily. This is definitely not true of the NiMH batteries in Tidalforce front hubs! I've noticed huge amounts of sag from my 1000W S-750 X motored bike I call "Red." Voltage drops down to almost 30V when I ride my bike at wide-open-throttle or WOT. I was shocked to find this out recently.

So in order to keep the speed up and to utilize my X motor to it's fullest capabilities, I need to find out 1 critical thing.

What is the high voltage cutoff (HVC) of the Tidalforce motor.

I need to find this out by testing the controller with a variable power supply and find out the what the actual voltage the TF bike controller will not accept and just shut the controller down. If I have a variable power source that can vary in small increments from 36V up to around 50V, I should be able to find this out. This number may vary with each bike since it's an analog circuit and there are variances in the parts and in the wiring.

After discovering this number, I then need to design a low-sag battery that will come very close to this HVC so that I can maintain the highest speed.

The A123 20Ah prismatic cell may just be the perfect choice. It is made up of 3.65V maximum voltage cells and so can be customized to voltages in increments of 3.65V.

This means that a 36.5V battery would be made up of 10 of these cells.
An 11 cell pack would give 40.15V.
12 cells would give you 43.8V.
13 cells would give you 47.45V.

Along with the maximum charge voltage, the batteries can be charged with custom settings on the charger. The Hyperion EOS 1420i NET3 charger does this very well. It can be customized to charge to any voltage you select.

So after determining the HVC of the Tidalforce controller, we will design a battery to suit it to perfection!

More later,

Sunday, May 27, 2012

Soldering Iron for CHEAP!

One of the things I really need in order to do some careful soldering is a temperature controlled soldering station. I'm used to working with old fashioned Weller soldering stations but they are now overpriced and hard to find. A newer station line has appeared to be the favorite and it's named Hakko. However, it is on the expensive side as well. I just spotted a new iron on that looks to be a clone of the Hakko series and it's called the YiHua 936.

The price is an amazing $16.51 and it's usually stocked in the USA warehouse. I just ordered mine and hopefully, it will arrive back in stock in the USA warehouse soon!

LED and Laser Tail Light

I picked up a new tail light yesterday. It's a combination LED and laser lights. The lasers create two red lines that outline a zone around the back of the bike and creates an area that hopefully, drivers will avoid. I liked the idea when I first heard of it and the price seemed fair on eBay. It was just over $10.

The actual tail light portion has 5 LEDs and 3 modes. Solid on, all flashing, and single LED rotation. The last mode cycles through all 5 LEDs one at a time. It's not the brightest tail light, but I bought it mainly for the lasers!

The two downward firing lasers have two modes. Solid on and flashing.

Here's the video.

I mounted it to the back of the Topeak MTX Explorer rack with the help of a small section of PVC tubing. The Topeak has an inverted "T" shaped plate which isn't very useful for mounting 3rd party lights, but a quick use of a pair of plyers allowed me to break off the wings of the "T" and use the remaining stub to mount the PVC tube.

More later,

Side view

Back view

LED pattern

Top view

Laser pattern

Rear bottom view showing the laser ports

Bottom of the LED/Laser light

Thursday, May 24, 2012

Ride in Rock Creek Park 5/23/2012 with my wife

We had a bit of time between errands yesterday so we took the bikes out for a spin through Rock Creek Park down the trails instead of on the road. The Tidalforce bikes are so quiet that we often come across deer. Check out the video at the 4:10 minute mark!

Here's the ride out:

Here's the ride back:

Here are a couple of photos of the bikes. I still think the Tidalforce iO cruiser is one of the sickest (in the good sense) looking bikes around. Very sleek and has a kind of a gangsta, art deco feel to it! :) The double kick stand is a wonderful addition to the bike.

Monday, May 21, 2012

A Summary of the Updates Done to "Red," the Tidalforce S-750 Electric Bike

I was adding the latest item to "Red," my Tidalforce S-750 bike I picked up on eBay back in December and was surprised at all the changes! In no particular order, here they are:

1) I replaced the dead front hub motor with one that I picked up from the seller of "Red." I did this by swapping out the inner battery core from the good battery to the dead one.

2) I replaced the working rear 750W Wavecrest Tidalforce motor with the higher performance 1000W X version  motor I picked up from the same eBay seller. The totally black Alex DM18 rim adds to the drama!

3) I added a Cycle Analyst meter from Grin Technologies to monitor the power usage and battery state of charge. It is by far, the best ebike meter on the planet. It's simple, straightforward, gives you more information than you'll ever need. It will let you know when things aren't right with your bike/battery. Worth every penny!

4) I added a new version Cane Creek Thudbuster LT to the bike. It significantly improves the ride of the hardtail Tidalforce. The action is as smooth as butter and there's no stiction so the response is immediate and completely smooth.

5) I added a Mirrycle rear view mirror to the left end of the handlebar. I don't feel right without this item on all of my bikes!

6) I added a double kickstand to the bike. This turns the bike into a very useful bike repair stand whenever it's down. I bought this one from Oatnet on, however, I don't believe he has them any more. The one I link to is from the same manufacturer, but it's adjustable, unlike the one I have here.

7) I added folding pedals to the cranks. This doesn't seem to be such a big deal, but it makes it MUCH easier to move bikes in and out of storage!

8) I added a $1 bicycle bell. It lets me warn others that I'm coming in my silent ebike!

9) I added a Magicshine MJ-808 bike light to the underside of the handlebars. This is one of the brightest, and smallest headlights available. The price is also fair.

10) I mounted the GoPro HD Hero 2 mount to the front strut of the Tidalforce bike. This position allows for wide panormic views of the scenery without being in the way.

11) I used a Velcro Velstrap to wrap up the large bundle of connectors near the rear motor. This will be one of my next projects for this bike. I've got too many bulky connectors near the rear motor and my foot hits this bundle when I'm riding.

12) I added a chainstay guard on the crank side of the bike. This prevents damage to the chainstay from the bike chain.

13) I added a Topeak MTX Explorer rack to the back of the bike! 

That's all for now! I love this bike and the smooth, silent, and effortless power it provides and enjoy riding it as much as I can. The (mostly) simple additions I've added to the Tidalforce ebike simply add to the enjoyment and safety of riding it!

More later,

Topeak MTX Explorer Rack for Red Tidalforce S-750

I took advantage of REI's biggest sale of the year and picked up another Topeak MTX Explorer rack for my red Tidalforce S-750 bike. My grey S-750 and my iO Cruiser both have the MTX Explorer rack already and to keep it all in the family, I bought the same rack for "Red."

I'll post a summary of all the updates I've made to "Red" since buying it late last year.

More later,

Tuesday, May 15, 2012

Pics of the Tidalforce S-750 with a Cycle Analyst installed

I had some free time on Sunday morning to work on the bike so I installed a Grin Technologies Cycle Analyst V2.0 on my Tidalforce S-750X. This particular S-750 has a very curved handlebar which gives you a very upright riding position. There's very little straight handlebar room to mount additional accessories. I had to squeeze the Cycle Analyst mount between the Tidalforce console and the stem mount.

In order from left to right: 
Mirrycle MTB Bar End Mountain Bicycle Mirror
Ergon grip trimmed to fit
Twist grip front derailleur shifter
eBay $1 bike bell
Cateye cycling computer
Magicshine MJ-808 headlight
Stem mount
Cycle Analyst V2.0 from Grin Technology
Tidalforce Console
Tidalforce Thumb Throttle
Twist grip rear derailleur shifter
Ergon GP1-L grip.
Here's the view from the front.

I found a bit of room to mount my Magicshine M-808 700 lumen headlight under the bar as well. It's pretty crowded!

I don't know if I'll switch out the handlebar for the straighter one on my grey S-750 but so far, The straighter bar would allow for more items to be mounted. I like the curved bar so far so won't do it right away.

More later,

How can you tell visually if you have an X motor?

I took a close look at the motors that I have from Tidalforce to see if there were any obvious differences between them. I took a couple of pictures of the labels. See if you can tell the diff!

Here's the label on the standard 750 watt Tidalforce motor.

For comparison, here's the label on the 1000 watt or X version of the Tidalforce motor.

Hmmm, hard to tell the difference, no?

More later,

Finally have an X motor working on my S-750X!

I took a couple of hours on Friday night to true the X motor wheel. It took a bit of effort since I don't have a truing stand, but roughed it with just the wheel mounted on the bike and using the brake pads as my truing calibrators! It worked relatively well. I took it out for a quick ride on Saturday and it felt really nice. I didn't have my Cycle Analyst installed so couldn't tell how much power the motor was using, but it felt much better than the 750W non-X motor.

Friday, May 4, 2012

Clear photos of the welded tabs of the 7S3P A123 packs

Oatnet or JD on has posted some very clear photos of the uncovered A123 packs. They show how the A123 20AH prismatic cells are welded and how challenging it might be to disassemble these packs. This further discourages me from buying these in order to try and harvest the individual cells for my purposes. See the photos here:

More later,

Wednesday, May 2, 2012

Bad News on the A123 20AH Prismatic 7S3P Packs

Some folks have finally received the highly anticipated 7S3P made with the A123 20 AH prismatic cells and have detailed pictures on

HumboldtRc received a couple of them and they have some major issues for folks interested in taking them apart to harvest the individual cells. First off, the tabs have been severely trimmed to about 1/8"! Second, they are welded to each other and so harvesting them will require removing these welds or cutting the metal that connects the tabs which is also challenging without damaging the individual cells. Third, they don't seem to be brand new cells. They look as if they're pulls from pre-built units, perhaps cars and then resold. Fourth, they are not consistent. The two that HumboldtRc received are constructed differently with different color insulators. Who knows what else is different about them!

Here's the video he made of them.

Here's the thread of photos of his packs.

Looks like I'm heading more in the individual cell route now... Sigh.

More later,