Simple battery simulator

[Rachie5272]

I'm looking for a simple Li+ battery simulator, for testing charging circuits.  I don't need anything fancy, and don't even need to measure the output precisely.  I need more of a dummy battery, in order to keep the charger trying to charge.  Something which simulates a half-charged cell, and will simply dissipate any current sourced by the charger.

Does such a thing exist, or do I need to buy a full benchtop load/simulator?

Thanks!

[ResistorRob]

You can do this pretty easily with a DC power supply and a DC load with the outputs hooked together.   Set the power supply to your desired battery voltage, and set the DC load to constant V mode, a couple dozen millivolts above the output of the power supply.  When your circuit tries to charge the battery, the 'battery' voltage rises  a few mV, but not enough to trip OVP on the power supply and the load starts sinking current.

[bdunham7]

Why not a 3.3 volt 5 watt zener diode in series with a 1 ohm 1 watt resistor?  That would be a 'good enough' simulation of a small cell with a max charge rate of about 1 amp.  Just parallel a few if you want to simulate a larger cell.