Ok I have searched, can't find anything.
I have a high capacity lithium ion battery testing rig, and I have some iCharger 406 units that are doing the testing for me. That side works awesome, and I can charge/discharge the lithium ion 3.7V battery at up to 70A.
These lithium ion cells are from EVs - 55Ah - very high capacity.
These units are able to both charge the lithium ion cell from source, plus regeneratively discharge the lithium ion cell back to the supply (at about 80% overall efficiency). Maximum current draw from 12V source during charging is about 27A.
My problem is that if I use a lead-acid source battery (12V car) then after 3 or 4 cycles the source battery is depleted due to the losses in regeneration.
I'm thinking of putting both a 12V battery plus a 12V computer DC power supply in parallel, using a diode on the power supply. I know that the computer power supply works fine on its own with this setup.
DC12V --->|-+--iCharger---LiIon Batt ------/
I understand that this is oversimplifying, but the idea being that the battery would have a higher voltage than the power supply for the majority of the time, and thus be primarily discharged until about 11.3V (12V - forward voltage drop of diode on the +12V DC power supply), at which point the power supply would pretty much be supplying the majority of the power.