Hi,

Can somebody elaborate on the pros and cons of Series and Shunt PWM based charge controllers?[/b]

it is basically how the power is regulated in what it does with it. shunt will short it for a brief time and series will disconnect it for a brief time. picture a garden hose that needs only a set amount of water to do whatever. the shunt takes the excess water and lets it go to the ground while the series just shuts it off at the nossle. this is not a similtaneous diversion or partially off as it is either to the load or not and can be thought of as a fast switch set to either go to ground or be off when not going to its load or task. hope this isn't confusing you. the shunt has to dissipate the heat from the power and so i recommend the series.

In an ideal PWM controller there is no power loss through heat dissipation. No controller is ideal. Both shunt an series PWM techniques can be lossy, since they are can not meet the theoretical and ideal switching with real devices (usually MOSFETS).

Go by the controller's efficiency spec's. That being said, there is a slight advantage to series, since there is no short circuit current with the associated I²R losses.

Thanks guys. That was certainly informative. though, I did read in a particular book that the Shunt technique was safe and swift. In addition that the PV panel should be able to handle the Short-circuit current.

Have you guys come across problems with products that actually use the Shunt technique?