12.5 AH now is 8.3 ??????

Second ride with the hew HPC striker motor and speed controller with the same 52v battery that is 12.5 which would give my old mac 10 about 15 trail mile s before I used 12.6 ah up and it would cut off . Now with the new BMC same wind as the Mac it cuts off @ 8.3 AH and only 11 mile CA says max amp 29 @ 1500 w about the same as my Mac 10 but I have lost 4 AH ? whats going on ???

How old is the battery and what type is it? How many cycles on the battery and how often have you run it down to cut-off? Be aware that discharging a battery completely will shorten its life significantly. Is the controller the same as the previous unit. Do you ride at a higher speed with a higher average discharge rate than before?

Does the battery voltage sag more now under load with the new motor/controller? If you've never taken notice before; charge your battery up then go out and gun the throttle from a standstill. Record the peak amps, minimum voltage and the resting (no-load) voltage from your CA. If you divide the voltage sag by the peak current you'll get a good indication of the battery's internal resistance. It's a good idea to do this when the battery is new and periodically after that for comparison. As the battery ages the internal resistance increases and the voltage sag under load increases. As the voltage sag increases the BMS and or controller will cut-out sooner and sooner providing less and less usable capacity.

Also be sure your battery is actually charging and balancing properly. If the charger output voltage is too low the battery will never properly balance. The only sure way of knowing if the cells are balanced is to check the individual cell voltage directly on the BMS after a charge cycle. Checking each cell voltage manually after the BMS shuts down will also allow you to identify if one or more cells is abnormally weak.

-R

PS, Assuming you have a direct connect Cycle Analyst it needs to be calibrated to the shunt in the controller to provide accurate information. If this was not done and verified with an ammeter or inline wattmeter then the readings it provides will be inaccurate. If you are using a stand-alone model then it won't be affected by the controller change.

That much gone overnight, It does seem like your CA calibration could be the problem. Likely it is using more power, so less range in miles.

The BMC is a little more powerful but just a little the mac would do 27mph and the BMC does 30 just about what I expected but I lost 4 ah ?????? not what I expected . The CA is showing 29 amps max the same as with the mac with the mac it would cut out when I used 12.6 ah out of my battery that would be 15 trail miles or as much as 22m on the street ,now with the BMC it cuts off when I use 8.2 ah @11m from the same battery pack to lose 4 ah seems to me to be too much of a loss does this seem right???

Is the CA "direct connect" or "standalone"? If it's the former it needs to be calibrated to the shunt in the controller. If the CA does not have the right shunt resistance value it will not give the correct Amps, Amp-hours, or Watt-hours. If you have a standalone unit it has an external shunt so no re-cal would be required. If that's the case then re-read my first post.

-R

The Ca plugs in to the speed controller just like my old speed controller , how ever to day I rode a battery pack out all on paved bike path and I got 22mi which is as good as I have ever gotten with the old setup . But the ca still displayed 8.3 AH ummm so my old CA needs to be calibrated to the new speed controller ???

Yes, the CA needs to know the resistance of the shunt in the new controller otherwise the values it gives for current, Ah and Wh will not be correct. The shunt resistance value may be printed on the controller, if not you'll have to calibrate it using an ammeter or in-line wattmeter.

-R

I agree. Your shunt will not be the same with a different controller. So you are way out of calibration with the new one.

It might be tricky to get it adjusted perfect, unless you have another, stand alone type, watt meter to compare against.

Though not perfect, comparing against one of those cheap blue watt meters could be close enough. so get one of those off ebay.

Meanwhile, just mentally adjust to the new, off calibration empty point. Until you get calibrated, 8.3 ah is empty. Still 12ah in reality, but the pack is empty when it says 8.

I have E mailed HPC after reading the reply's I have not read anything about this before, so I buy a kit from EMV3 a mac with speed controller and CA but the battery is from HPC . It works fine I run it for a yr the ca displays 12.6 before it cuts out as I ride and learn what it will do I notice that my miles would change you can't go by just mileage ie I get more miles when I ride the street vs trail this makes sense . But the battery always cut off at the same AH 12.6 but now after I put a HPC motor and speed controller with throttle on with the same battery (which is a HPC battery ) it now reads 8.3 AH when it cuts out . Since it is a all HPC system why dos it need to be calibrated I Have not heard of this before and it doesn't sound like its easy or normal .

rider95 said:

I have E mailed HPC after reading the reply's I have not read anything about this before, so I buy a kit from EMV3 a mac with speed controller and CA but the battery is from HPC . It works fine I run it for a yr the ca displays 12.6 before it cuts out as I ride and learn what it will do I notice that my miles would change you can't go by just mileage ie I get more miles when I ride the street vs trail this makes sense . But the battery always cut off at the same AH 12.6 but now after I put a HPC motor and speed controller with throttle on with the same battery (which is a HPC battery ) it now reads 8.3 AH when it cuts out . Since it is a all HPC system why dos it need to be calibrated I Have not heard of this before and it doesn't sound like its easy or normal .

Click to expand...

Your original kit from EMV3 was a motor, controller and cycle analyst, right? Then you changed just the motor and controller, right? OK then I will explain one more time. A direct connect cycle analyst does what it does by reading the voltage across a piece of metal in the controller called a shunt. By reading the voltage and knowing the resistance of that shunt the ca can calculate the current (basic ohms law). When the ca is initially programmed that shunt resistance is entered into the device. Evidently this was done for you by EMV3 (or maybe not and you've been using a default value all along). From then on the current the ca displays and the amp-hours and watt-hours it calculates should be accurate. If you never actually verified the ca calibration you don't really know for sure though. Anyway the new controller you installed has a different shunt with a different resistance. The ca doesn't know this. You need to enter the shunt resistance of the new controller into the ca. Most folks who sell controllers with a ca plug will check the resistance of the shunt and write it on the controller so the end user (you) can enter that value into the ca. That's what you need to do!

If you don't have the shunt value you can still reprogram the ca but you'll need either a multimeter (and know how to use it to check current) or an in-line wattmeter.

Here is what an in-line wattmeter looks like;



This device does some of the functions of a cycle analyst in that it measures the current and calculates ah and wh. It has it's own internal shunt and is calibrated at the factory. You can place one of these between your battery and controller then change the shunt value in the ca until the ca agrees with the inline wattmeter.

Read about and download info for the cycle analyst right from GRIN;
http://www.ebikes.ca/product-info/cycle-analyst.html
http://www.ebikes.ca/documents/CycleAnalyst_V23Web.pdf

-R

That's what HPC is saying the shunt value is 1.88 and I have the ca that has the speedo cable and mag pick up so how do I change the shunt value in my ca?? I have a program cable I bought with my ca do I use that ??

rider95 said:

That's what HPC is saying the shunt value is 1.88 and I have the ca that has the speedo cable and mag pick up so how do I change the shunt value in my ca?? I have a program cable I bought with my ca do I use that ??

Click to expand...

The instructions are all in the second link in my previous post.

-R