Little confusion on suitable wire awg for watt meter

minexplorer

Esteemed Pedelecer
Aug 22, 2017
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Four Lanes,Cornwall
The meter is fitted with 12 awg.Ive got tons of 16awg and cant see the point in buying more.I want to tune the controller to 18amps and prob leave permanently as its display,so is 16awg ok im wondering. After all i notice the wire from the battery and controller is 16awg. Also the wire from my bbs01 controller which is 18 amp max ,looks only 18awg (rated for 10amps).Its eclipse battery 14awg .All very confusing as internet research says only 12awg wire is rated to take 20 amps .Indeed the watt meter is 150amps so 12awg ?? Appreciate if someone can put me straight,thanks.
 
D

Deleted member 4366

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If you take the shunt out at place it between the battery and controller, you can use 24g, but if you w don't do that and want to have the meter on your handlebars, you need at least 14g wire to and from the meter. Note that you only need that on the negative wire to and from the meter. You can still use 24g for the positive and you don't need a return because the positive is only used to power the meter. The measurement is only done on the negative wire. They only give you two thick wires on each for convenience when you want to connect the meter directly between the battery and load.
 

minexplorer

Esteemed Pedelecer
Aug 22, 2017
532
93
55
Four Lanes,Cornwall
If you take the shunt out at place it between the battery and controller, you can use 24g, but if you w don't do that and want to have the meter on your handlebars, you need at least 14g wire to and from the meter. Note that you only need that on the negative wire to and from the meter. You can still use 24g for the positive and you don't need a return because the positive is only used to power the meter. The measurement is only done on the negative wire. They only give you two thick wires on each for convenience when you want to connect the meter directly between the battery and load.
thanks d8veh ive got enough 14awg for one run up to handlebars an back. If i dont just connect a single wire from the pos to power it,but want to run that back also,does that then need to be 14awg as well ? .I want to be able to try it out on both bikes. Just popping it in with the same connectors ive used to join the batteries to the controllers.Wont be left permanently fitted.
 
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Deleted member 4366

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If you want the meter on the handlebars there's absolutely no point in running a thick positive to the meter. You run the positive directly from the battery to the controller and run only a thin spur from it to the meter battery side.

Running the positive to the meter will double the power loss and look ugly.
 

minexplorer

Esteemed Pedelecer
Aug 22, 2017
532
93
55
Four Lanes,Cornwall
If you want the meter on the handlebars there's absolutely no point in running a thick positive to the meter. You run the positive directly from the battery to the controller and run only a thin spur from it to the meter battery side.

Running the positive to the meter will double the power loss and look ugly.
hi d8veh thanks.I totally get what you mean.Sounds more sensible. It was from the point of convenience i was thinking of, just pop the watt meter in and out as i please on either bike. having a wire stub with connector, permanently spliced to the battery pos wire down by the batt / controller connectors will be neat enough. just have to remember to cap it from rain when not in use .
 
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Deleted member 4366

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You can still do that. Use deans connectors. Cut the battery negative; solder a male connector to the controller side and a female to the battery side (that's only the negative wire); splice a spur into positive; solder the spur to the female positive; then on your meter, solder a male on the battery side and a female on the controller side. When you take the meter out, you can connect the two deans on the controller and battery together.
 

minexplorer

Esteemed Pedelecer
Aug 22, 2017
532
93
55
Four Lanes,Cornwall
You can still do that. Use deans connectors. Cut the battery negative; solder a male connector to the controller side and a female to the battery side (that's only the negative wire); splice a spur into positive; solder the spur to the female positive; then on your meter, solder a male on the battery side and a female on the controller side. When you take the meter out, you can connect the two deans on the controller and battery together.
thanks d8veh ill look these deans connectors up