Power/Amperage Monitoring

[slowguy]

My PIM bike has the usual 5 bar battery monitor which is fine but I realize that I could exceed my battery and I might not get back with a flat battery at my age and wanted to monitor how much power I actually use in PAS mode or regeneration mode

. I purchased a very inexpensive HALL effect meter, a kind of a clamp meter. I realize I need to disconnect the power line going into the rear drive in order to do this well as tap into a source to run the display. (This can be achieved with a 9v battery same size as the merge but it looks kind of off-putting). Then I started thinking about warranty and playing with the wiring and thought to ask for advice.

Has anyone experience adding a current meter? Would really like to know how much I drain under PAS etc.

 

[harryS]

You put it on one of the two main battery lines, not the wires going to the motor. Might be hard to view when riding. Looking at the PIM ebike line-up, don't see an obvious way to expose a battery line w/o compromising the warranty.

I'm a retired engineer, so I get a kick out of monitoring my power usage. I have used a clamp-on ammeter and now use an RC wattmeter. It connects to the battery, but my ebikes are conversions with no warranty. I know how much miles/AH I get at a given speed. I'll then use the rated AH on the battery to estimate my range for that speed,

I also have measured how many AH it takes to recharge a flat battery. I don't like to run a battery that far down but sometimes it's worth seeing if the manufacturer is honest. No one lied on my batteries.

My meters display real time amps, but I cannot see the meters so I don't have that info. My LCD will show real time watts though but that is always fluctuating, so I suppose the amps would too.

 

[slowguy]

The only available power wires have disconnects near the power unit. I had assumed that I could run a wire through the sensor. Still not sure why that would not be a solution. No way to get at the battery connectors without opening the multi-plug and tapping in.

 

[6zfshdb]

This won't help you I'm afraid but many ebike handlbar displays include a crude current indicator. The one on my Pedego looks like this:

The more dots displayed in the left hand colummn, the higher the current drain. Its rather crude but it gives you a real time readout of how much power you're using.

 

[harryS]

I can't see what your PIM does on the battery wires, but you have to put the clamp sensor on one of the main power wires that go to the controller, wherever that is located.

If the controller was inside your hub motor, then you could split the cable to find the power lines, but usually they're in the frame.

You can always run your battery down to one bar and note the miles and speed, Then you know your effective range for that speed. Hills/wind will shorten things.

The PIM being a direct drive motor, you should try riding it w/o a battery to see how hard it pedals. It might tell you you never want to run out of power.

 

[rich c]

Current monitor is a confusing name. Monitoring watts? That can help you while hypermiling, but not much good for monitoring amps used. The cheap RC monitors are okay since they will display amp hours used. If you battery has a capacity of 20ah, you have a better idea of when you better be close to home when you see 19aH used. The cycle analyst is a much better option. The model CA-SA has a remote shunt so you don't have to run heavy wire up to the handlebars. Much higher price, but very useable data! http://www.ebikes.ca/ca-sa.html