Controller for portable solar panel : Is Mppt better than Pwm? (1 Viewer)

[Captain Yoghurtpot]

Am considering a stand alone , foldable , portable solar panel around 100 to 150 W.
Have seen various types, but am currently looking at one around the £250 mark with mppt controler, but a very similar model with pwm controller is significantly cheaper.
Anyone have any recommendations on makes also?
Thanks

 

[Raul]

Your calculations are off. I got 182wh, per day. Or 15ah. A 50w panel will not help you from end of September to beginning of April. In fact, you will struggle on cloudy summer days. A 100w panel with pwm controller will need 3hrs of full output ( sunny) to replace the 15ah consumed, plus a bit of absorb. In general lead round trip efficiency is max 70% so for every 10ah you take, you need to harvest at least 13ah, before absorb. Also, it still needs to be able to hold the float, while you discharge.
Have a look at this,

And consider a small mppt with a 100w panel.

 

[Captain Yoghurtpot]

Your calculations are off. I got 182wh, per day. Or 15ah. A 50w panel will not help you from end of September to beginning of April. In fact, you will struggle on cloudy summer days. A 100w panel with pwm controller will need 3hrs of full output ( sunny) to replace the 15ah consumed, plus a bit of absorb. In general lead round trip efficiency is max 70% so for every 10ah you take, you need to harvest at least 13ah, before absorb. Also, it still needs to be able to hold the float, while you discharge.
Have a look at this,

And consider a small mppt with a 100w panel.

Very much obliged.