Turnigy Watt Meter ???????

[averhamdave]

Ok, for my project bike - Chinese duct tape Lipo, crazyman brushed controller, Powabyke hub - I have now sent for one of these Turnigy Watt Meters:-

Turnigy Watts Up Meter Power Analyzer Free XT60 Plugs on eBay (end time 13-Jan-11 10:09:50 GMT)

Just a few basic questions for me to understand before it arrives and I install it:-

What functions (that are worth noting) will this meter show?

Will I wire it in series in the positive feed from the battery or in parallel, coupling to both pas and neg?

It will live in my rack mounted topbox battery carrier, be permanently connected and only looked at at the end of a ride and during charging.

Thanks, Dave

 

[Orraman]

While not the same model you could get a great deal of information from a recent thread. ~~

http://www.pedelecs.co.uk/forum/electric-bicycles/7340-remote-watt-meter-13-less.html

A different supplier with comments.

HobbyKing Online R/C Hobby Store : Turnigy Watt Meter and power Analyzer

Dave

 

[Deleted member 4366]

You wire it in series so that the power from the battery goes directly through it before anything else. If it's anything like the other one, it displays it's readings in real-time, So when you look at it in your topbox, you'll only see ah used and present battery voltage. With the lipos, you need to keep an eye on the battery voltage that it doesn't drop below the minimum. I think your controller has a minimum voltage cutoff, but you need to confirm what it is and test that it's working with a voltmeter or your Turnigy (if you trust the result). You can get lipo low voltage alarms that fit to each pack that'll tell you when cell voltage is too low, but they also need to be checked. I think NRG found that the accuracy varied from one to another.
Here's what I found out about installing lipos - if it helps: When you do your installation, make sure that the batteries and leads are securely fixed so that there can be no rubbing or pulling. The wires come very close inside the pack and any pulling on them can cause a short, which'll give an instant serious fire. I guess some are better than others, but when I looked in mine, I can see how easy it is for them to fail by mishandling. When you fit the connectors, the live terminals should ALWAYS be females, so that no live contacts are exposed. That means that you put female on the batteries, the output end of any battery harness wires, the output end of your Turnigy and so on. These batteries are so powerful that the moment you let exposed terminals touch each other or any metal object, you'll get a firework display, probably damage your pack and possibly set fire to your bike/house/garage. I hope havn't scared you. Provided that you handle these batteries properly, there should be no problem. Finally, you will probably need to solder connectors to the battery packs. I used Taylor type that means soldering the terminals close together. I did actually accidentally short the terminals slightly whilst doing it and there was a flash and two of the internal cell connections blew leaving a dead pack - that's how I know what's inside. Luckily I was able to repair them. I wouldn't recommend soldering on these type or similar connectors unless you have a very steady hand.

 

[wurly]

They are good handy little meters. I use mine for charging and use it on the bike for a when i am on a long ride. I can tell how much power (Whr) i have used and how much is needed to recharge. It will allow you to view peak amps, which is nice to see if you had no idea before. I am tempted to make mine remote and fitted to the handlebars, but i like the idea of tempory fitment also. Then again...they are cheap enough, i might buy another and have one fitted permenantly. Not sure if they are waterproof though. If you are fitting it inside a battery bag then you shouln't need to worry about that.

 

[averhamdave]

While not the same model you could get a great deal of information from a recent thread. ~~

http://www.pedelecs.co.uk/forum/electric-bicycles/7340-remote-watt-meter-13-less.html

A different supplier with comments.

HobbyKing Online R/C Hobby Store : Turnigy Watt Meter and power Analyzer

Dave

Hi Orraman and thanks. Yes I know I could have bought the cheaper model and could have bought from Hobbyking - I deal with them regularly as I do RC Helicopters. Problem is I'm away into europe in a couple of weeks for several weeks, with the bikes and I want it fitted by then. During the break I would be hoping to do several hundred miles on the bike.

Apologies for misleading on the battery - it is the Cheap Chinese Li-ion featured on these pages a few weeks ago! Its not a lipo so should be relatively safe anyway. So far it looks very good. I will be fitting some Lipos in the spring though to the Ezee Torq so will be back again d8veh although I have a few years experience with them now through RC.

The controller shows a low battery cut-off of 31.5 volts. Is that a bit low for a 36v Li-ion that comes off the charger at 41v?

Ok, so packed away in the top box:-

It'll be away from the elements
Be wired in series in the positive line from battery to controller.
Will show actual voltage, peak amps reading, watt hours used - and I presume, if I could see it the actual amps at any time?

Thanks for now, Dave

 

[NRG]

It will show instantaneous amps and watts and the current batt volts all the time then peak volts, peak watts, peak amps, total Ah and Wh used via a scrolling display. I think I'll add one to my Alien and mount it remotely but will use the watts up meter as there are reports of the Turnigy version not measuring correctly. They are not waterproof but that's easily fixed.

 

[Pedalo]

...as there are reports of the Turnigy version not measuring correctly.

Yes I saw some odd results as shown here:

http://www.pedelecs.co.uk/forum/electric-bicycles/6964-turnigy-power-meter-accuracy.html?

After my initial interest to see how things were performing when I first put my ebike together I've not used it since.

 

[averhamdave]

Yes I saw some odd results as shown here:

http://www.pedelecs.co.uk/forum/electric-bicycles/6964-turnigy-power-meter-accuracy.html?

After my initial interest to see how things were performing when I first put my ebike together I've not used it since.

Mmmm, having now done a few hundred miles with the Watt Meter fitted in the battery enclosure I would agree that once having gathered initial info about how the bike/battery is performing I've hardly looked at it!

My Torq which is fitted with one of those cheap (but excellent) chinese duct tape batteries on the rack (36v 15ah) seems to happily discharge well over 450wh of power without showing a deteroration in performance, pulls 17ah through the controller (an e-crazyman special as its now sensorless), peak draw is about 700w, will dip down to about 32v and after 30 miles of heavy riding in the hills is at about 38.5v at rest.

Maybe I've posted in the wrong thread looking at the content!

Good battery, good controller, noisy old Bafang 250w motor!