Workman Stretch Mover Electric Trike - power not speed

[zap]

...I made an 75 foot extension cord for the charger. Normally the charger stays put in a cool and clean house, while the extension charging cord is plugged in and out all the time. But it just so happened that I added that rear disc brake. When I did that, I brought the trike inside, I disconnected the extension cord and used the charger directly into the battery. Thus plugging and unplugging that connector.

This almost sounds like the extension cord is for the charger's output?
If I'm wrong and it's for the charger's input then no big deal.

If it's for the charger's output then there's a good chance you're dropping quite a few volts unless the extension is made from some seriously big conductor.

 

[jeff peterson]

Yes the extension cord is connected to the 30v output of the charger with connections to match. Thus I did not have to cut any wires of the charger to add or remove the extension. The extension which is made of 12 gage wire with water tight ends and has been used for months without any issue. I checked continuity of the extension and it seems to be fine.

Before installing the rear brake the charger worked fine with the extension. When I was installing the rear brake the bike came inside, the charger extension was removed and the charger was plugged directly into the battery pack. At that time the charger worked fine, red LED showed that the charger was powered, green LED [and fan would run] showed when it was charging. After installing the rear brake the charger worked fine. Now [a few days later] the charger will not go to green when it plugged into the battery pack.

I wonder if I should try to charge a 24v SLA battery pack? Just to see if the charger would go green and try to charge it?

 

[zap]

My response was mainly about using 75' of extension cord, not the problem with your charger.

There are a bunch of voltage drop calculators online. This one http://www.currentsolutions.com/vdrop.php showed a 1.2v drop using 30v @ 10a.
Nothing severe... just something to think about.

I wish I could help more with the charger issue, it does sound like a loose/broken wire... good luck with it.

 

[jeff peterson]

I checked the 10amp Ping charger without opening it up: The output wire connections appear to be clean and solid, no major change in voltage when moving the wire ends. Meter reads around 20 volts when on [should be 30v]. LED light is very dim [must be in a dark room to see it is on]. Fan tries to move every few seconds but does not spin on it's own [if you help it, it will spin slowly]. Amps are very low, though the volts show 20v, it dimly lights a 2.5v 300ma flash light bulb.
FYI - SLA charger now shows a green light. This means the charger thinks the pack is charged. But from what I've read, it may not be fully charged or balanced.
[I'm happy to see a green light for a change!]

I'm no expert or even a talented hack..... but I think the Ping charger is toast. I was hoping to hear from Ping this morning and get his thoughts....

 

[amberwolf]

If it's voltage output is that low, that's probably why the fan/etc won't even start. My guess is something on the primary side of things where it is not even pulsing the first transformer fully. That could be caused by the control circuit, or by not getting enough power into it, or bad caps not filtering the input AC power correctly, or bad switching transistors, etc.

Also could be a loading problem on the output side, where bad caps are leaking current and keeping it from going high enough voltage, or bad pass/etc transistors, diodes, etc.

Even a bad solder joint somewhere could cause it.

 

[jeff peterson]

Here's the latest:
Ping sent a new charger, I just paid $30 for shipping. I received the charger in about 5 day. [I think thats pretty darn fast]
The Ping battery pack seems to be fine charging on the SLA charger. But there is a little loss in the top end speed. Guessing that's due to the lower voltage of the SLA charger. I'll plug in the new Ping charger tonight, after I ride around a bit. I'm guessing that will make the BMS kick in and do their thing.

Since I didn't have to send the old charger back, I'll like to try to fix it. Or at least, learn something. I opened the old unit up, the only thing I noticed was that a round coil of wires seems to be very dark compared to a smaller coil. I'm guessing that larger coil saw a bit of heat, otherwise nothing looks or smells burnt.

I'll check the current drop on my extension cord and hope to take pictures of the new rear brake and the insides of the old charger this weekend.

 

[jeff peterson]

It's been a while since I've updated this post. The new Ping charger is still working fine. In fact, this whole project has been a success! I have over 500 miles on the trike this summer. Between trike and trailer I have hauled over a thousand pounds at 12 mph without pedaling. This was achieved on nearly flat ground, in 2nd gear, high rpms on the electric motor and no more than 20 blocks along the beach. [see picture] Good thing I added the rear disc brakes!

On average, the trike hauls 400lbs empty [my weight, trike and battery] 20 to 25 miles at 18mph using a 40amp/hr 24v ping battery has been the norm this summer along the flat shore line. Vacation is now over, the trike is home, Rickshaw rear seating will be removed this weekend and replaced with a flatbed and cooler. It's now time to climb small hills with recycle waste,construction material and the normal local shopping.

 

[zap]

Thanks for the update.
It's great you got all the bugs out and it looks like things are fine and dandy!

 

[jeff peterson]

Another quick update. I now have over 800 miles on the trike. In general, everything is perfect, the only thing that has broken was the main motor drive chain. I was still able to pedal home. A new heavier duty chain just arrived. I'll pre-size a few and put them in the tool bag.

I'm toying with the idea of adding a second matching 450 watt currie motor and controller over the winter. [I wish currie made this same 24v motor with 750 watts of power]

Here are a few newer pics after adding a disc brake to the rear axle.

 

[jeff peterson]

It's spring and time to pull out the trike. I now have 850 miles on it, and except for a few bolts and screws being loose. I'm in good shape for the summer. I'm still thinking about adding the second motor and I have a few question for those with background knowledge....

If I were to add a second motor, should I use:
One 1000 watt controller to power both motors?
or
Two 500 watt controllers to power each motor one to one?
[and this may seem really foolish ]
Can you wire 2 controllers outputs into one main output, powering the 2 motors at the same time from the one main?
Would the 2 controllers fight each other?

FYI - I have the second motor and controller and my battery is from Ping, it's a 24V 30AH V2.5 LiFePO4 Battery Pack.

 

[dumbass]

It's spring and time to pull out the trike. I now have 850 miles on it, and except for a few bolts and screws being loose. I'm in good shape for the summer. I'm still thinking about adding the second motor and I have a few question for those with background knowledge....

If I were to add a second motor, should I use:
One 1000 watt controller to power both motors?
or
Two 500 watt controllers to power each motor one to one?
[and this may seem really foolish ]
Can you wire 2 controllers outputs into one main output, powering the 2 motors at the same time from the one main?
Would the 2 controllers fight each other?

FYI - I have the second motor and controller and my battery is from Ping, it's a 24V 30AH V2.5 LiFePO4 Battery Pack.

WOW, finally I am an expert on something....LOL Let me tell ya I just went through the same thing a week ago. I see you are using a Currie type motor assuming it's 24v. I have an EZIP with the motor (motors now) relocated to the center of the bike. The motors actually drive through the bikes gearing so as I shift up/down so does the motor gearing. I actually installed the second motor as a backup only. Not intending it to actually be used. But like you I wanted more speed and or power. And like you I couldn't decide which way to do it. I finally decided to install a second 24v controller. So I was running 2 24v 35a Currie controllers (one to each motor) but wired to 1 throttle. In my shop testing it worked great except one motor was turning at 490rpm and the other at 515rpm. Not a big deal because the faster motor will just load down a little sonner and the slow motor will catch up. I was totally disapointed with the real world testing. I found that I had more torque but little or no more top speed. I thought I would gain a little speed because the motor wouldn't load down quite so much. OK, so last week I installed a 48v 50a controller and wired the 2 motor together so they were sharing the voltage and current. The results were exactly the same. Which I find very strange. Think of this.....I have twin 24v 20ah 2c lifepo4 packs capable of producing 24v 80a continously or 48v 40a continously. So when using the 2 24v 35a controllers they should have pulled 24v 70a or 1680w at full load. And the single 48v 50a controller will try to pull 2400w. But the end result was pretty much the same. More low end torque but little or no added top speed. But this maybe exactly what you are looking for. If so I would recommend going with a single 48v controller. The amperage is something you need to decide based on your battery power. The setup takes a little more efford but it's a lot cleaner in the end. And if you need to buy a second controller anyway then the cost is about the same too. You will need 1 new motor, 1 48v 50a (you decide on amperage) and a 48v controller. You can use your old 24v controller but do not connect the votage lites if you have them.

PS...With the 48v setup the motors still run a exactly the same speed as they did before or seperate controllers (490rpm and 515rpm). Like I said strange.....

Hope this helps.....If you need more info feel free to IM me.

Bob

 

[jeff peterson]

Hey Bob, Thanks for the info. Glad to hear you have tried most of these ideas.

My trike is not about speed as much as it is about torque, so what you found is of interest to me. The other day I was able to haul 10 bags of mulch on my trike. Due to the extra weight, I had to drop the normal gearing down by 1 to keep the motor from straining. I'm wondering if I had 2 motor, would I be able to maintain my normal speeds? And of course gain a few mph.

Sadly I have only the one 24V 40AH V2.5 LiFePO4 Battery Pack [30AH was a typo] I can not use a 48v controller like you can, I must stick with 24v. But from what you've learned, it seems that it does not to matter what controller I use, if the input numbers are the same, so is the output. Thus the 2 controller idea should work fine if I split the throttle signal like you did. BTW - I'm told if you want more speed you need to up the voltage. example use a 36v controller with the 48v battery configuration. [but becareful, I really don't know if this is a good idea nor have I ever tried it myself.]

Like you I'm using the gears to help move me along. I have a 3 spd unit offering about 8mph in 1st, 13mph in 2nd and 18mph in 3rd on the flats. On bridges and overpasses I often use 2nd, Yes it's slower but there is also less motor whine noise and the motor's rpm are higher. It just seems more effenct. [this is just a guess on my part] Any chance you tried the Nuvinci hub?


A few more questions if you don't mind.....
when running double motors and acheiving about the same speed:
Was the motor temp any cooler?
Was there less motor whine?
Were you able to climb hills better?

 

[dumbass]

Jeff,

1) When you say your pack is 24v 40ah what is the C rating? Basicly I too have a 24v 40ah pack. Of course in my case it's really 2 24v 20ah packs with a 2C rating. So I can draw a continous 24v 80a if needed. So if your pack is also rated at 2C then you can also draw 80a at 24v. This is important because a standard Currie controller draws a max of 35a each. So can your pack handle a 70a draw if needed? Of course we all know this will not normally be the case because 2 motors will not normally double the current draw. But......

2) Yeah, to increase the motor's output speed you really have to up the voltage. But for the sake of the gearbox I prefer not to over volt the motors.

3) As I said you may see some small increase in speed with twin motors but that would depend on how hard you were loading the single motor. In my case I wasn't loading that badly so I saw no major inprovement. However, when I did my test I didn't have my speedo working so I based my opioion on feel and how well I could keep up peddling. My setup with 1 motor tops out at 20 to 22MPH. So I was expecting this to increase to maybe 24 or so. But honestly I can't say that it did or didn't for sure.

4) 2 controllers are hard to work with and take twice the space. First off you are not really splitting the hall (throttle) signal. You are sharing it. By this I mean you connect 2 of the 3 hall wires to the second controller. So you need to buy (but where) the end connector for the hall wires to plug into the second controller. Of course you could just cut off all the connectors and twist the wires together. Personally I would always want some kind of connector in case you need to unplug it (even a Radio Shack connector). The setup did work but I decided to try a single 48v controller and new throttle. Personally I don't think it made much if any difference. The biggest advantage to a true twin setup is redundency. If one motor fails or controller fails and assuming you set it up with 2 switches you can turn off one or the other motor/controller. In your situation you could also try a single large controller...say a 24v 70a. Kelly control makes them in that size. But I guess for your situation you are better off with the twin setup for the value of redundency but don't forget a second freewheel for the second motor.

5) Motor Temp......no idea. I never had my motor on my bike nor my wife's bike get hot. I was always able to put my hand on it and the gearbox right after an hour long ride. And my test rides have only been a few blocks so far. But I'm sure in your situation if you are getting your motor hot a twin motor will help it significantly. It will also reduce your current draw because the heat is lost electrical current. Therefore, you may not use any more battery then you would with a single motor

6) motor whine......Can't really say if it changed any because I had just done a lot of work on the motor gearboxes to reduce the noise. So any noise reduction I had I would like to think was because of this efford. But if you feel your motor is less noisy when in a lower gear at the same speed then twin motors will reduce your noise factor in the same manner.

7) Hill Cimbing...Again sorry but didn't ride enough to say. But as I said I could feel the difference in torque on take off. Don't be looking for a neck jerk but you should feel the difference. So it would have to improve your hill climbing. I would guess if you are currently on the edge of a gear (lets say gears 2 and 3) and with a single motor youfeel the need to gear down to 2nd you would likely stay in 3rd with twin motors. However, there will always be a difference in power consumpsion in a higher gear. You should use a meter of some kind so you know when downshifting is a value to you.

8) My bike has been running with this setup (single motor) through a Nuvinci hub for over a year. The motor does drive through the gearing of the hub. So like you my motor sees the value of the ratio changes. The Nuvinci hub is heavy (6 pounds more then a standard 6/7 speed gear cluster that I had) but I feel it is worth it. Until I have to life the bike up onto the car rack....LOL Remember my bike is a standard hard tail bike not a trike.

As I said if it will help in anyway feel free to send me an instant message and I will be happy to give you my phone # and we can talk futher on anything you want to know about my testing......PS...I am going to be removing the Currie motors and controllers sometime very soon. I bought a new motor/controller setup without gearbox. I am planning to use a belt drive reduction to kill the noise and hopefully increase my torque and top speed.

If the rain holds off I will try another test ride soon and this time I will have a new speedo installed and let you know if there was any top end improvement.

Bob

EDIT: BTY, what size wire are you using? Depending on how long your wire runs are you should be using 12 or 10g high quality wire. And don't try to coupleup to that same wire for a second motor. You will need a total second set of wires to handle the amp load.

 

[dumbass]

Jeff, A quick (unlike most of my posts) followup for you. I installed my speedo and took a few short test rides. The max speed was 23MPH. I did several runs with a set of Currie SLA 3 year old packs. As you may know they are rated at 24v 10ah and as I said are SLA 3 years old. Max speed withpeddling was 22 and the motors alone could maintain between 20 and 21. With a combo of 1 24v 20ah TS lifepo4 pack and one of the Currie SLA packs I got the max speed of 23MPH and it could maintain maybe a half MPH more. So lifepo4 does do a little but not that much. The main value of lifepo4 pack will come as the miles add up and the packs start to sag more. That's when life will start to shine. Hope this info helps you decide.

I could feel a big difference in the torque. So much so that I think I did something to my Nuvinci hub because it started to slip. So badly that on one run I had to peddle home. The fact that it would peddle and not work with the motor is strange though. I checked all the chains and everything was fine. So ether the added torque of the motors caused slipage in the hub or the freewheel of hub drive sprocket is slipping. I am guessing there's no problem inside the hub and the problem is the sprocket of freewheel. Cheap freewheels have been known to break a dog and cause this type of problem. So my vote is on the freewheel. We'll see as soon as I have time to take it apart.

Hope this info helps you decide.


Bob

PS...I paid more attention to the motor noise this time and for what ever reason the noise level was about 1/3 as bad as it was last year on one motor. So was it the mods I did or the twin motors not being loaded as badly. I'll call it a combo effect. But at say 15MPH I no longer will lower my head because ofthe noise when I pass someone. It seems to get quiter the more I ride it too. Hmm

 

[jeff peterson]

1) The battery was made by Ping, 24V 40AH V2.5 LiFePO4 Battery Pack. I do not know the rating.

2) I agree, I'm sticking with the suggested numbers.

3) I put a strain on the motor, thus the reason for the gears and the thought of buying a Nivinci unit.

4) I have the correct male and female connectors to make a "Y" adapter for the throttle. The space and weight of the controllers is not an issue. I was thinking about putting the 2 motors on one chain. No additional free wheel. But I can see how that might not be the best idea. I'll rethink that idea.

5,6 & 7) My motor seems to get a bit more than warm. [not hot] But since I can carry a 1000lbs on the trike, I try to put myself in the motors place and drop down the gears so there is less strain on it. Thus why I was thinking about twin motors. If one motor can do what I want it to do, then 2 motors should work better if I don't add any more weight. I also understand the 2 motors could draw twice the current from the battery. But like you I doubt it as long as I use common sence an gear down when needed. The battery cable looks to be #6, I used a #6 mechanical bug to drop to the #12 wire on the controller. I can connect a second #12 wire on the same bug without any issues.

Nivinci hub: What is the diamiter of it? By just looking at it, it seems to large in dia to fit in my frame. Any chance you can measure yours?

The Trike: My trike is more like a home made pedal cab. The frame is a Worksmans stretched mover, I also have an addtional trailer that mounts to the rear if I nee more hauling room. [about 250 lbs empty] The trike spends the summer at the beach going between bars or food joints. In the fall and spring it hauls waste to recycle location and is my main runabout. In the winter it rests, I have no plow attachment at this time.

Thanks for all the help and knowledge!
I'll try to add the motor tonight

 

[dumbass]

I am very sure you will notic the additonal torque with a second motor. And if you are actually loading the motor as you think you are (and you must be) it will likely kick up the speed a little. But under normal situations it will not actually pull that much more current. Only when you are going crazy which is why I commented about the battery current doubling.

I agree it sounds like your wirering should be fine.

The Nuvinci is about 6 3/8" dia. How would you install a Nuvinci as a mid-drive or on one of the wheels or ??

 

[jeff peterson]

Hey Bob,
Thanks again for all your knowledge! I pulled the motor rack and installed the second motor. I realized I could not add an additional free wheel since the power goes through the single sprocket of the 3 speed. It's a shame there isn't a free wheel on the motor. On the bright side, there is also nothing to break....

Because I had thought about putting the second motor on last year, I had the extra motor, controller and connectors. I had also bought a heavier duty chain to replace the BMX chain I was using. It only took about a hour to drill new mounting holes and install the second motor. Another hour to wire and solder connectors. Then another hour to assemble and alline all the parts. Or so I thought.... Though the trike sounded fine in the garage, on the road it sounded like a bad derailer. I made a number of adjustments but I could not stop that noise while riding. Finally while free wheeling the motor I tried putting a load on the rear drive by applying the break. That instantly showed the problem. The second motor add too much torque to the mounting frame and torque twisted it when applying load. I thought about the problem for a while, ok a few hours and came up with a cheap fix. I added a peice of pipe hanger straping to the top of the motor and mounted it to the frame. Though the strap is made of thin metal, it didn't take much to keep it firm. Of course, this is just a patch, but the idea works!

Sadly, by the time I resolved the torque issue, it was mid-night. A little late to make test runs on the main road, so I tried a few things on the driveway. As you stated Bob, there is a huge increase in torque. It feels as if my weight and the weight of the trike [aprox 500lbs total] is no longer an issue. The trike really steps out without pedaling and come right up to speed in first gear. Sadly that's as far as I could go testing it last night.

There were a few other issues I found while removing the old wiring. Mainly that the mechanical keyed starter switch I use to disconnect the battery is a bit to weak for the single motor. I know 2 motors will make short work of it if I continue to use it. So, tonight I'll stop at the marine an buy a keyed boat battery switch. They are way over designed for my needs. It's also suposed to rain tonight. If it does, I finish the wiring and clean-up the garage!

I'll update this post after I make a few test rides.
Thanks again Bob!

 

[dumbass]

Jeff, Quick question... I am assuming you are using twin 24v 35a controllers correct? Whos? And I'm interested in how you did the hall wires. Did you connect all 3 hall wires to both controllers or just jumper 2 wires to the second controller? The hall conection was an original problem for me because my controllers would not allow me to use all 3 connections on both controllers. It caused a feed back and would cut off one of the controllers (never the same one ether). Bottom line I got it to work but didn't really like it which is why I went to the 48v controller. Let us know if you get a speed increase too.

The only real reason for a second freewheel is to reduce the load on a single freewheel and to be able to turn off one motor if it has a problem. With the load your carrying that's a lot on a single freewheel especially if it's a cheapo one. And now your adding more torque to it. When I did my little test yesterday morning I had a problem with one of the motor's idlers so the chain for that motor was loose. So when I hit the throttle the chain would jerk. I think I broke one of the dogs in the final motor freewheel because at first I lost all drive from the motors but I could still peddle home (seperate chain). But after reving the motors in the garage a few times suddenly it worked again. I think what has happened itthe broken dog has locked it's self and is now perminantly engaged. When I built the setup I actually built in a safety by installing a freewheel driving a freewheel. So the second freewheel that normally would never be called upon to actually freewheel in now taking over the job. Hope you have better luck. Maybe this weekend I will take things apart and see what happened for sure. Bob

 

[jeff peterson]

Yes, twin motors and controllers.

My motors are the 450watt # MOT-24450G
http://www.electricscooterparts.com/motors24volt.html

Controllers are Currie Technologies 24V 600W Electric Scooter Speed Controller # SPD-SD600
http://www.electricscooterparts.com/speedcontrollers24volt.html

3 Pin Throttle/Speed Controller Connector Set With Pins # CNX-52 [bottom of controller page]
http://www.electricscooterparts.com/speedcontrollers24volt.html

I bought the 10g power leads from B G Micro a while back.

I made a 3 wire wiring harness tee to run the throttle to both controllers. They just plugin using the connectors, I did't have any problems.

I'll know more about speed over the weekend. But my guess is that I'll gain a bit of speed due to the fact that I won't need to gear down as much when it just me and the trike. But top speed will still be about 18mph, that's simply the way I geared it due to the state law maxing my speed to 20mph. [I'll post on Monday]

I bought my free wheels from Staton Inc. and connected them to the 7/8" drive shaft. Staton seems to use strong parts due to there gas motor putting out more torque. Since I have a HD trike, weight and balance is not an issue. Plus ever since I replaced the SLA weight with the ping battery. I seem to cruse without worrying about a battery life. Though I did run out of power once, it seems the charger died and it took me a few day's to notice. Please remember my speed is slow compared to the 2 wheelers, thus I don't have the wind drag you faster folks have and I personally believe that kills most of your battery power.

Please let me know if you need more info!

 

[dumbass]

Yeah, I bought my freewheels at Staton too. As I remember most of them are Ditca freewheels (not the best quality on the planet but not the worse ether). I will likely pull the bike apart this weekend and see what happened. It's a real PITA to take this freewheel off the bike..I have to pull the crank sprocket to get at it. Would have liked to go riding on Sunday though. Supposed to be in the 80s here.

 

[dumbass]

Jeff, I just took a look at the Pick battery site and unless you had him custom build a pack for you you I am guessing you have a 20ah pack. http://www.pingbattery.com/servlet/the-6/24V-20AH-V2.5-LiFePO4/Detail This pack is a 2C pack and is fine when you were running 1 motor but with 2 motors you best keep a close eye on you current draw. As we agreed you will likely not draw the max current (70a) of your 2 controllers. But the pack is rated for 2C or 40a Max continuous discharge. If you don't have some kind of on board amp meter you may want to consider one. Bob

 

[jeff peterson]

Yes Bob, I had Ping costom make my 40ah battery fo me It was not much more than the 30ah and according to what I was reading, power is always the issues. Thus why not over build!

Okay, here is the latest after adding the second motor. The trike now feels more like a a real machine and less like a toy. At full speed in 3rd on flat ground I'm now seeing 19.6mph. That is the max speed. I now can maintain 15+mgh on all local hils when before I neded to gear down to second or first gear. But that speed is at a price, I seem to be pulling more power from the battery, I judge this by the time it now take to recharge the battery. Though I have not felt any lessening in power after a 12 mile run ,I'm sure more power is being consumed. I'm now going to replace the drive chains do to the increased motor power. Then I'll start retesting again.

 

[dumbass]

Jeff, OK, that explains the fact that Ping doesn't list that pack on his site.

Sounds like the twin motors are going to work for you. It might still be better to gear down for the big hill to save battery power. You really should consider a meter of some kind so you know what your real power draw is. You can pick up some for $20 to $30 and they will give you valuableinformation. Bob

 

[jeff peterson]

I agree with you Bob, I'd like to know more about what is going on... Can you point me in the right direction for meters?

I removed the chain comment. I called Workmans Cycle, I have their chain on the rest of the trike, since those chains show no sign of any wear issues. I'll simply buy 10 feet plus both master and half links.

 

[dumbass]

I agree with you Bob, I'd like to know more about what is going on... Can you point me in the right direction for meters?

I removed the chain comment. I called Workmans Cycle, I have their chain on the rest of the trike, since those chains show no sign of any wear issues. I'll simply buy 10 feet plus both master and half links.

Jeff, I like the "Cycle Analyst" http://www.ebikes.ca/drainbrain_history.shtml but it is exspensive so if you go with one of these do your shopping. I use (you should to) the "Stand Alone" model. YOur controllers do not have the plug required for the other model. Please note that continuous current is 45 Amps continuous with a 100A. Again considering your worse situation I'm not sure if 45a is enough for you or not. There is a less expensive meter available but I just can't think of it's name. IF I remember it I'll let you know. I think it's under 30 bucks and does most of what you need. It might also have a max of 70a. Bob

EDIT: Watts up meter Here's a link but again do your shopping If your do a search on this forum for watts up there are a lot of recomendations where to buy them. http://www.google.com/products/catalog?q=watts+up+meter&oe=utf-8&rls=org.mozilla:en-USfficial&client=firefox-a&um=1&ie=UTF-8&cid=4376920761853901310&sa=X&ei=qsmkTYHfLZKMrQHwl8WeCw&ved=0CCYQ8wIwAA#