Power/Watt Meter for a 72V eBike

Hey guys. What do you guys use for a power/watt meter for a 72V ebike. When I had my 36V system, I used the RC 60V power meter. It was really easy to install since you just wire it as you would a connector. But, I am looking at the ones for the above 60V, and they require a shunt with like lead wires to the power meter. This seems really confusing to me and I am hesitant to do it since I am sure I am gonna fook something up disasteriously.

Is there a more simple power/watt meter like the RC onces where I just connect negative and positive for a 72V system. What would happen if I run 72V through the 60V RC power meter? I don't mind if the voltage doesnt read I just need the amps and amp-hours.

Probably you get smoke, because it's rated 60v to protect the electronics in it (which might be able to handle 63v, probably not that).

If you don't connect the power positive (probably red) wire, that lets it tap power off the system, and instead run it off of a separate battery just for the meter that is low enough voltage for it, then it would work like you want it to (wrong voltage, watts, watthours, but correct amps and amphours). You'd need to run a bypass wire for the positive so that it will still pass power to the controller, but not connect that positive wire at all to the wattmeter.


A shunt inline with the battery to controller is exactly the same as putting the whole wattmeter inline with the battery to controller, except that you don't have to run high current wiring all the way from your battery up to your handlebars and back down to the controller, you only have to run thin signal wires (from the shunt to the meter).

Some meters, like the Cycle Analyst, have a shunt that literally just plugs in, if you already have anderson PP45 connectors on controller and battery, so there's no wiring to mess up. (or you can get the one with no connectors, and put your own on, or just solder everything directly with no connectors, like I usualy do).

bakaneko said:

Hey guys. What do you guys use for a power/watt meter for a 72V ebike. When I had my 36V system, I used the RC 60V power meter. It was really easy to install since you just wire it as you would a connector. But, I am looking at the ones for the above 60V, and they require a shunt with like lead wires to the power meter. This seems really confusing to me and I am hesitant to do it since I am sure I am gonna fook something up disasteriously.

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Wiring to a shunt isn't that big of a deal. I managed to do it OK. That said, there are some meters that use a Hall effect sensor. One of those might be worth a try.
https://www.amazon.com/DROK-Display-Digital-Multimeter-Voltmeter/dp/B07B4CWKRJ/ref=sxbs_sxwds-stvp?keywords=coulomb+counter&pd_rd_i=B07B4CWKRJ&pd_rd_r=b33ac0db-a591-4757-9326-7492ddfe2cc8&pd_rd_w=qn220&pd_rd_wg=23R7O&pf_rd_p=5c5ea0d7-2437-4d8a-88a7-ea6f32aeac11&pf_rd_r=KF4PKJSMGWT9KZ5X61MG&qid=1554498984&s=gateway

I really like this one...

https://www.amazon.com/dp/B0714CZQZ...&pd_rd_r=c2857d29-57eb-11e9-8ef0-0b4f280728eb

the problem is I like high current a lot more so I ended up buying this one

https://www.amazon.com/Wireless-Vol...94XCQ272MZ35&refRID=TE3HTJJN94XCQ272MZ35&th=1

Just need to cut the black or negative wire, put a ring terminal on it and bolt it down and you're good to go.

Okay, I might give that shunt power meter a try if not the hall sensor one. I just kinda hesitant with the shunt as it needs to be well insulated. I mean I don't want to short at 72V...

Hard to swallow the cost of a Cycle Analyst, but once you do you never regret it. If nothing else, it eliminates the problems of mounting it, installing the shunt, etc. The stand alone model is the one that comes with a shunt and a speedo sensor.

dogman dan said:

Hard to swallow the cost of a Cycle Analyst, but once you do you never regret it. If nothing else, it eliminates the problems of mounting it, installing the shunt, etc. The stand alone model is the one that comes with a shunt and a speedo sensor.

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And it supports Grin - the folks that make this site possible and who are also ebike advocates. It is certainly worth considering - especially if you expect to be ebiking for a long time.