Newbie SMB transit owner with prewired Zamp controller system. Just bought Nature Power solar panel and it also has a prewired controller on back of solar panel. Are two controllers a problem? Does this reduce solar energy getting to the battery? I have searched exhaustive online and no mention of this issue.
Short Answer is yes, this would generally be a problem. The output of the "controlled" Solar Panel should not be fed into the other controller. In this case I guess your Zamp controller. You could bypass the Zamp controller and run the Nature Power and run directly to the battery system. IMO this is not the best solution. If you can return the panel and get one without the built in controller I would do so.