Morningstar SG-4 SunGuard 4.5 Amp PWM Charge Controller 12 V

I've been using these for years to charge 12v deep cycle batteries with solar. They work great in the north florida sun and humidity. Out of about 35 of them I've only had a few fail over the years. Slightly expensive but far better than the cheaper solid state charge controllers.

Perfect replacement

Keeps our battery charged and won’t let it unload through the solar panel at night.

This a good regulator for a small solar panel and works well. It would be nice to have an LED or somethin to let you know it was charging, but then it might not be waterproof. You will need to use a meter to check charging current.

Well the first one lasted nine years, the last two lasted 30 days each. Will not be back a third time.