Hi,
There have been a number of tests suggested for the Batteroo to see how it lives up to the claims made by Bob. These test involve time, waiting for the cells to discharge. The outcome of these tests can be predicted with a simulation like this:
This is a macro model of a generic boost converter. Three parameters are required to fit the model to the Batteroo.
The parameters are:
Iq - This is the quiescent current for the boost converter, measured with the output in regulation, but no load. In the model the Iq load is placed on the output side of the boost converter. This is because I believe the 'stuff' inside the chip will be powered from the output side.
The Iq parameter shapes the efficiency plot at light loads.
Rl - This parameter represents losses that are proportional to input current squared. It represents losses in the inductor and switch inside the boost converter.
The Rl parameter shapes the efficiency curve at the higher output currents.
Eff - This is the mid current efficiency. This determines the efficiency at medium currents.
Here is the efficiency plot, using typical parameters:
When these parameters have been determined empirically, the model can be fitted to the measurements. Once the model has been tuned in the performance of the Batteroo with various loads can be predicted without having to wait for the batteries to discharge.
I have attached the LTspice model.
Regards,
Jay_Diddy_B