eCalc - electric drive simulation and calculation

reliable electric drive simulations

For general questions "How to use..." read the Help Section (link to help in upper right corner of your calculator)  first, visit our eCalc YouTube Channel or eCalc Q&A on
For specific questions or problems proceed according these procedures below and contact us if problem stll exists - info[at] - with a screen shot of the entire browser window and problem discription.

 General Procedure

eCalc does not work - Login not possible - motor data not load?
It might be, your browser is still using an old library or your browser session has expired after 2h of continuose use. To solve the Problem you have to force your browser for a complete reload. Preceed as follows:
  1. Close ALL (!) browser windows
  2. restart your browser
  3. go to and choose your signed-up calculator
  4. when you are on your signed-up calculator, force your browser to reload all files by reloading the page while keeping the key
    - [shift] for FireFox and Chrome
    - [ctrl] for Microsoft Edge
    firm pressed.
  5. Now Login with your credentials in top right corner.
  6. reload the page again according 4.
  7. If the problem still exists please send us a screen shot of your calculator right AFTER the unsuccessful Login.

Frozen Safari on Apple

On some Apple device using Safari the browser will be frozen for a long period when opening the calculator. The root cause is a problem in Apple's keychain. You can circumnavigate this problem by logging in on the homepage in the right upper corner and only after logging in choose your calculator.

Payment Language

PayPal Payment form turns up in a unknown language?
In some rare cases the payment form of PayPal is shown in a foreign language. The language on PayPal may be changes by clicking to the yellow marked link (or similar):
propCalc for fixed wing aircraft

Stripe Payment Error

Error «Sorry this email address is already registered»
For reliable identification of a user we accept only unique email addresses. If your entred email address alredy exists in the database we can not accept a second new registration on same email. For renewing your membership make sure you pay at the renewal page where we will accept your existing email to prolonge your membership.

Motor Data

eCalc does not load (single) motor data?
Most problably a motor database update did take place and your browser is still using the old resource. Solve the problem by proceeding the procedure abouve «eCalc does not work» closley.

Gauges not shown

I can not see the Quick Check Gauges or there is no indication
We recommend to update your browser. Microsoft Internet Explorer is not supported anymore.
The Quick Check Gauges are a ressource from Google. As a few countries (e.g. China) have restricted access to Google the Gauges may not be displayed, sorry.

Calculation Error with custom battery

We have increased reports of occuring calculation errors:

Your Setup is unrealistic and way out of Limits!Your Parameters lead to a calculation error. Please check your input parameters.
[Error: Division by zero (11/Microsoft VBScript runtime error)]

Check your entered battery data. These data represents the specification per cell. Most probably you have entered the pack voltage (e.g. 11.1V) instead of the cell voltage of 3.7V!

Expiry date

Wrong expiry date?
To all users used to american date format month/day/year - we remind you eCalc does show the expiry date in european date format: day / month / year


membership expired?
For security reasons eCalc does quite the browser session after a long time of inactivity or after 2h of continouse use. That might result in a "membership expired" message although you membership i still active.
Please close all (!) your browser windwos, restart your browser and login again.

Login on Navigation Bar

Login on Navigation Bar throws you back?
When trying to login on the navigation bar and you will be thrown back to the same page, then you are allready logged-on - just proceed to your calculator. On the calculator page you see a login form (not logged in) or your name (if logged-in) in the right upper corner.


Forgot password or not received?
Enter your username (your email address) in the repective login field and click the link «forgot password?». Our system sends a email with your credentials with a reset password with an activation link (please check also spam filter and junk mail folder for a email from info[at]


no login received?
After sign-up you should receive a email from info[at] to your PayPal eMail Address with your credentials. Please check also your spam filter or junk mail folder before contacting us by email.