MB-1-E Part Eighteen: The Test Flight

MB-1-E's picture

Hi All,

I got my 30 Amp DPDT Switch from Digikey today.
It's a about twice as big as the cheapo switch I got on eBay and looks well made.

I had to rework some of my lugs (connections) to the switch since the screws are also about twice the size of the last ones. I slipped some heatshrink over each wire before tightening them up then heated them gently with the torch. I taped the connections and exposed screws well and then tried to figure somewhere to place the switch within reach of the existing wires.
I finally ended up going up and over the top horizontal frame tube and it fit pretty well like that, so I wire-tied it down.

I don't know what I was thinking, but I sat on the bike when the kickstand was down. I was going to check for pedal clearance and make sure that the switch would not get hit by my leg when pedaling.
The double leg kickstand twisted forward and flattened my CrMo tube frame a bit. I checked it out and it did some damage but should be structurally sound since it's right next to the BB and part of a very solid triangle.
I'll never do that again :(

I checked the rest of the bike as a general maintenance check, adjusted the chain just a little and headed out the door.

As usual, the bike took right off, smooth and quiet.
I rode the usual back streets, headed down the power line trail, down some more roads, different dirt trails and back home. I decided to go another round, so I rode the streets some more until I was getting a bit tired.
I headed home then decided to try another round.
Eventually, fairly near home the controller kicked in to energy save mode (reduced current) so I headed in for the evening.

During this whole ride I hadn't pedaled at all except to assist slightly on a hill or two.
My speed tops out right at 20 mph, some times a little more, sometimes slightly less depending on the wind, grade etc.

My Odometer read 17.36 miles today with an average speed of 14.4 mph. This includes the slower rides up and down a number of dirt trails and some casual riding through some neighborhoods. A good deal of the time I was riding with the pedal to the metal, right at 20 mph.

I think I could definately increase my range by being a little more conservative on the throttle and pedaling once and a while.

All in all, I feel this was a good test run and I now have a better feel for what she'll do.

My stated goals were to go 20 mph with a 20 mile range (at reduced speed).
I think I've nearly accomplished that, next ride I'll slow down to 15-16 mph and see how far it will go.

Once I got the bike inside, checked the voltage and the batteries were at 11.53 volts. I switched over to 12V parallel and put the charger on it. The IOTA 3-stage went into bulk mode and is charging away.

I don't plan to drain my batteries this low often but had to know what the limits were.

I'm a pretty happy camper! :) Fun Ride!!


before comments


echuckj5's picture


I use odyssey batteries. On my owner's manual it states that ll.5 volts is dead. 11.7 volts is 10% charge.

I re-read all of your blog again today, I think I finally got it right, you have a doc Watson meter.

Is'nt there a way this can be hooked up without running all of the battery voltage thru it? Even if you could monitor one battery I think it would be helpful.

A meter at this time for me would be just for asthetics, I never tax my battery pack, being in the city I pretty much know how far I have to go. About the furthest I have gone is 10 miles on a trip before the batteries are on a charger.

Is that Doc Watson not usable?



MB-1-E's picture

The Doc Wattson has a 100A limit.
In order to use the Ammeter (thus determining my Ah use) is to place it in line between a source and a load. (i.e. The Battery and the Controller or the Controller and the Motor.

The problem being that my motor draws more than 100A at times.

Now I could use it when I charge the batteries also where the Charger is the Source and the Battery is the Load. This will tell me how many Ah until a full charge. This could give me a good idea of how much the batteries have been depleted.

As I've noted, I don't plan on depleting the batteries this low on any kind of regular basis.
I didn't have a volt meter on me.
Now I know what my limits are and don't plan on going past 50% if possible.
I know that draining the batteries past that will shorten their life considerably, I need them to last as long as possible (within reason).

I can place the Doc Wattson meter on one bank of the batteries just to determine voltage, so this would be a good gas gauge.

You posted it once before (I don't remember where), but what does your Odyssey manual list as Full, 3/4, 1/2, 1/4, if it does list it this way?

I had no idea I was getting the batteries down to ~2% left today or I wouldn't have done so.

I'd better get a volt meter on it!

Hopefully, I didn't hurt them too bad. I noticed that they went right up to 13 volts within about 10-15 minutes on the charger.

Oh, after 17+ miles of all out riding, the motor was a little hot but not too bad. I could hold my hand on it (pressing down) for 10 seconds before I really felt like taking my hand off. So I think the motor can handle that type of ride fine.

I can tame down the controller current draw a little so it's a bit easier on the batteries.
I also don't need to go 20 mph most of the time either. No traffic issues where I need to.


Electric - Bridgestone MB-1 Mountain Bike
Icon Photo of lighning striking Eiffel Tower Jun 3, 1902, taken by MG Loppe'

Dave B

<a href="http://visforvoltage.org/book-page/996-mountain-bike-conversion-24v-3-4h... - Bridgestone MB-1 Mountain Bike</a>

echuckj5's picture


Per the odyssey manual,

As long as the battery has not been charged or discharged for 6 or more hours, these figures can be used to determine the state of charge of the battery. 12.84 volts or greater-100%. 12.5 volts-75%, 12.18 volts-50%, 11.88 volts-25%.



MB-1-E's picture

Thanks Chuck,

Exactly what I needed.
I can set my controller for 12.18 volts for the low end and keep the batts within that golden 50% level.
Actually, I don't even want to take them that low most of the time but this will prevent me from going any farther if I do.
I think the controller must go into a reduced current state after that point, so perhaps I need to set it slightly higher than this. I noticed a rather abrupt reduction in speed and power but it still got me home fine.

Knowing this and adding my Doc Wattson as a Voltmeter should do the trick.

Thanks again,


Electric - Bridgestone MB-1 Mountain Bike
Icon Photo of lighning striking Eiffel Tower Jun 3, 1902, taken by MG Loppe'

Dave B

<a href="http://visforvoltage.org/book-page/996-mountain-bike-conversion-24v-3-4h... - Bridgestone MB-1 Mountain Bike</a>

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