PWM controller

Re: PWM controller

PWM (and MPPT) are just better at feeding just the amount of current/power needed by the battery bank to reach 100% charge and stay there. A PWM controller--think of a switch that turns on and off quickly--just feeding little surges of current to keep the battery charged.

Vs a dump controller that takes 100%+ of the charger's rated current and "dumps" it to a resistor bank. Basically "cycling" the battery bank while charging it. This can age the battery even while charging it. And makes it difficult to keep the battery at "float voltage" (i.e., at 13.6 with a PWM/MPPT controller vs cycling between 14.5 and under 12.7 volts while the sun is up with a dump type controller).

Solar panels do not need a dump controller. You can simply "turn off the switch" when the battery is full.

With horizontal axis wind turbines, they always need an electrical load. If there is none, they can over-speed and self destruct in average to high winds. So the "simple" way to do this is always keep the turbine connected to the battery bank and use a dump controller to limit battery charging while keeping a steady load on the turbine.

-Bill

Re: PWM controller

Yep, that would be a perfect controller for your needs. There is the 60 amp version that has a small Internet server on-board--If that is worth the extra bucks (and possibly a bit more losses to power the larger unit+server).

-Bill

Re: PWM controller

Several other suggestions.

The Morningstar TS Family of charge controllers supports a set of remote battery voltage sense leads. When I used to work with computers that had large power supplies and low/accurate voltage requirements, remote sense function was great.

Another option (to purchase) is the remote battery temperature sensor. The RBTS is handy because batteries' charging voltage requirements change with temperature (battery charging voltage goes up in cold weather). Especially useful if the batteries and the charge controller are not in the same space.

Lastly, as money allows, a Battery Monitor (or this brand too) is very nice. Much easier than measuring voltage and/or checking specific gravity every day. Especially handy if you have sealed batteries (like AGM) and/or spouse/kids/guests--They just have to look at the display and see what is required:

• 75%<SOC (state of charge)--all OK
• 50%<SOC<75%; watch loads, perhaps start genset next day if no sun and/or heavy loads are expected
• 50%<SOC; start genset and recharge >80% SOC. If SOC remains below 50% or continues downward, call for help
• 20%<SOC; turn off all loads, check generator, call for help--Battery bank in danger of permanent damage
• Get SOC>90% a couple times a week for long battery life.

Battery monitors are not perfect (you need to understand how they reset back to 100% full, as an example)--But it can save a battery bank from an early death.

-Bill