I have several of the Brunton chargers that I use to charge NiMH batteries. I have found that that they do not quite fully charge the batteries like I had hoped. I now use a smart charger to charge the batteries and then place them in the solar charger to maintain them until used. In a pinch and with several changes of batteries, the solar only option will work for most needs. Go to CandlePower Fourms ( http://www.candlepowerforums.com//ubbthreads/ubbthreads.php?Cat= ) and do a search, there is a lot of information on rechargeable batteries and charging systems. Pete