Watt meter TSDZ2

[whiteturbo]

The display i have on my Tongsheng is the VLCD-5 and it doesn't display voltage only black bars and absolutely nothing as far as amp usage and that makes me feel very insecure as i have no idea how much battery i have left, i am used to monitoring voltage on my BBS01 and don't discharge below 36 v(10s lipo) and the amps tell me how much the motor is contributing. So the answer is obvious, i need a watt meter but how do i wire it in to the VLCD-5 display. The Display has 3 sockets on it which i don't use, they are for the throttle and left and right brake cut offs, is it possible to wire a watt meter or similar device using one of those sockets?

 

[Deleted member 4366]

A wattmeter goes between the battery and the controller. It has nothing to do with the LCD. It simply measures the voltage and current coming out of the battery.

None of the cheap wattmeters are particularly waterproof and they all need some sort of modification if you want to see it while riding. Normally, that means fitting a shunt remotely and wiring it in. Some have remote shunts, but those ones would need to be mounted in some sort of waterproof box.

 

[whiteturbo]

Thanks d8veh i just wondered if it could be spliced into the brake lever cut off but as its not possible i will have to adapt to reading black bars instead of volts!

 

[Deleted member 4366]

No, the brake switch works at 5v. You can splice into the display wires to get battery voltage for a voltmeter, but the main current only runs between the battery and the controller, so that's the only place you can measure power.

 

[whiteturbo]

No, the brake switch works at 5v. You can splice into the display wires to get battery voltage for a voltmeter, but the main current only runs between the battery and the controller, so that's the only place you can measure power.

Thanks! thats another idea out the window then.

 

[Deleted member 4366]

Surely, if you can install a complete motor, you can install a wattmeter that only has three wires to connect?

 

[whiteturbo]

I got confused by the mention of the controller, As i understand it all i have to do is insert the watt meter inline between my battery and the power connections of the motor As my battery connector is an XT90 it should be simple. But to get the watt meter to the handlebars surly there will be 2 long positive leads and 2 long negative leads. That was what i was trying to avoid, is there another device similar which doesn't need such long leads or should i say long(thick 12 or 10 swg) power leads.

 

[wheeliepete]

The battery wires run to the controller, then from controller to the motor. If you want the watt meter bar mounted you can't avoid long, thick wires from the battery to the meter and then back to the controller.

 

[Deleted member 4366]

If you can solder, you open the wattmeter, take out the shunt/s and put them or a proprietary shunt of the same value in the negative battery wire, then connect with three thin wires, like a throttle cable, to the wattmeter on your handlebars.

I made a few threads about how to do that to every type of wattmeter, but the images got stolen by Photobucket.

This wattmeter already has a remote shunt, so is dead easy to wire up, but it's not waterproof, so needs to go in a box somehow:

https://www.ebay.co.uk/itm/DC-6-5-100V-100A-Digital-Voltage-Current-Watt-Power-Energy-Meter-LCD-Ammeter-AMP/142534506444?_trkparms=aid=555018&algo=PL.SIM&ao=2&asc=49129&meid=b44e5c8e57ef4829922969f362de54c9&pid=100005&rk=4&rkt=6&sd=322836804201&itm=142534506444&_trksid=p2047675.c100005.m1851

 

[whiteturbo]

Thanks d8veh thats just what i wanted

 

[whiteturbo]

Have just come across a Cycle Analyst v2.3 CA for £65 which would be the boy if i can wire it into place because its meant to plug into a standard battery 6 pin socket thingy and i use LiPo's so would it be easy to adapt. For another £10 it comes with speedo sensor, but do i need that seeing as my VLCD-5 Display has the speed stuff.

 

[danielrlee]

Have just come across a Cycle Analyst v2.3 CA for £65 which would be the boy if i can wire it into place because its meant to plug into a standard battery 6 pin socket thingy and i use LiPo's so would it be easy to adapt. For another £10 it comes with speedo sensor, but do i need that seeing as my VLCD-5 Display has the speed stuff.

A word of warning: The CA does NOT connect to a 6-pin battery balance lead. Doing so will destroy the CA in an instant.

The 6-pin CA plug connects direct to a matching CA plug on the controller and utilises the shunt already in there. This connection can be added to any controller.

Alternatively, you can purchase a separate remote shunt if you don't want to modify your controller

 

[whiteturbo]

Hi danielrlee, I was going to cut the plug off completely and rewire it, but maybe i ought to consider the extra(£130) and get the stand alone version. I have found an article showing how to wire it direct to a Hub system controller but its no good for me as i am using a crank drive and i have no intention of modifying the controller on that. Any info on how to do it using the shunt

 

[danielrlee]

Hi danielrlee, I was going to cut the plug off completely and rewire it, but maybe i ought to consider the extra(£130) and get the stand alone version. I have found an article showing how to wire it direct to a Hub system controller but its no good for me as i am using a crank drive and i have no intention of modifying the controller on that. Any info on how to do it using the shunt

The 'standalone' version is exactly the same as the 'direct connect' version, except it comes with the remote shunt already mentioned.

Instructions and diagrams can be found in the CA user manual on the ebikes.ca website.

Although I'm a huge fan of the CA, I don't see it as particularly good value when used as a monitoring only device, although a used one for £65 isn't too bad. Be aware though that the CAv2 functionality is far lower than the CAv3, which was redesigned from the ground up, although the monitoring only functions are similar.

EDIT: The CA requires supplying a 'pulsed' speed signal from somewhere. This can be split from your existing speed sensor, from one of your motor hall sensors, or from another standalone speed sensor altogether.

 

[Deleted member 4366]

Have just come across a Cycle Analyst v2.3 CA for £65 which would be the boy if i can wire it into place because its meant to plug into a standard battery 6 pin socket thingy and i use LiPo's so would it be easy to adapt. For another £10 it comes with speedo sensor, but do i need that seeing as my VLCD-5 Display has the speed stuff.

Basically, you'd be paying over £100 extra for a waterproof wattmeter. I doubt that you will ever use or need the other functions of the CA. The amount of work you'd need to do to wire it in would be similar to taking the shunts out of one of these and wiring it remotely. Once you have it open, it's easy to add silicone sealant to make it waterproof:

https://www.ebay.co.uk/itm/12V-150A-Digital-Volt-Watt-Meter-Car-Caravan-4x4-Camping-Solar-Power-Voltmeter/282738502314?epid=860674222&hash=item41d4872aaa:g:mswAAOSw3v5Yr9Ru