Solar - anyone regret getting PWM charge controller?

[Cdash]

Looking to do a solar installation and have been studying up. Think I'm pretty good on most of it, however, still struggling with the charge controller. As I understand it, the PWM kind of "chops off" power above the battery charging voltage, where MPPT is covering almost all the power down to the charging voltage, thus giving as close to all the power available.

MPPT sounds great, but comes at a cost, more than double. Enough to buy almost 200 watts of panels. I read about plenty of people that share that they are fully charged by noon or 1pm, with their MPPT controller. That means that the system has quite a bit more power than is required.

To me, it seems like a WPM could still charge the batteries, but may not do it till a little later in the day.

Is my thinking flawed?

Or am I just trying to be too cheap?

[landyacht318]

Most people incorrectly think that when their solar controller drops to float voltage, that the battery is fully charged.

This does not mean that, only that the controller held absorption voltage as long as it was programmed to do so.

How long one is required to hold absorption voltage and what that ideal absorption voltage is is different for every battery, different as it ages, and different when starting from different levels of discharge.

I recommend any quality solar controller, PWM or MPPT, which allows one to tailor Absorption voltage and Duration.

One wants their batteries to have achieved Absorption voltage by Solar by 1PM at the latest. More solar than this is not wasteful, it only makes for happier longer lived batteries, and more of a buffer in bad weather.

[pianotuna]

Hi,

Buy a controller that has:

1. a temperature sensor on the battery bank
2. a voltage sense wire
3. adjustable voltage set points

I'd stick with pwm right up to 500 watts, beyond that and I'd go MPPT. At 1000 watts I'd switch to a 24 volt battery bank.

[NinerBikes]

Under 30 amps, or 360 watts, PWM is fine, above 30 amps and more than 360 watts, MPPT will serve you better.

[corvettekent]

I have a MPPT with 320 watts of panels and yes most sunny days I'm charge by noon but today was a cloudy day so I did not get a full charge. You could save a couple hundred dollars by going with a PWM but if it does not work like you would hope then you will be spending more $$ on a new controller. You will be happy with a MPPT controller.