Super small (cheap) MPPT charger

[@adrianleitch6996]

Hi Jan, nice work on the uMPPT converter. I would love to see another video with two of the meters so you can measure real time efficiency. How have you have implemented tracking? Is it real time active tracking or just a fixed duty cycle setup? If it is real time is it the Perturb & Observe method, or full sweep, or fixed ratio of open circuit voltage?

[@stefanvandepas4249]

Hi Adrian, I am using a hill climbing method so perturb and observe at 15Hz. Simulations indicate an efficiency above 95% but I am also very curious how good it is in real life. Have to buy a second Portapow ;-)

[@off-gridretreat9293]

Fantastic would be also a travel version of your uMppt charger, input 6v-18V output USB! Like this one s.lazada.co.th/s.XMQcG But they perform not very well, waste a lot of energy, get very very hot. I usually use these travel 6V panels because they are very handy, easy to put in my bag as well charge directly my powerbank which is all I need. Since they already have a small W rating I would appreciate maximum possible energy harvest. I calculated that I waste for example minimum 2W with a pwm charger + 15w 18v panel in compare if I would use a mppt charger instead.

[@jansunman7393]

Well I would not use a 18V input and reduce to around 5V efficiency will never be very good with that kind of voltage drop. Also note with a constant output voltage like 5V you cannot do MPPT.

[@off-gridretreat9293]

@@jansunman7393 Oh I didn't know that, appreciate the information! I read in the description of one dc to dc charger module that the higher input voltage the higher the efficiency. See in description s.lazada.co.th/s.XMN5Q I also ordered that one, looked modern and neat! :) So for mppt the output voltage must be variable... I see, good to know.

[@off-gridretreat9293]

@@jansunman7393 They are so dirt cheap I ordered also this one s.lazada.co.th/s.XMDr2 and this one s.lazada.co.th/s.XMSHV They say an efficiency up to 96% which sounds pretty good! I figured that I can't use mppt for my daily driver which is the 6v 12W panel so (6v input to 5.4v to 4.9v output is a very small range and makes not much difference to use mppt I suppose) I got these dc to dc converters since they claim 90 to 96% which is pretty all right. Previously some of these charges destroyed my powerbanks (guess poor circuit and too high output ripples) or they performed lousy. They also get super hot. Hope one of these new ones will perform better than my present one. Will have to wait a few weeks till they are here since shipped from China.

[@off-gridretreat9293]

@@jansunman7393 Also thank you so much for replying!! I really have a lot of respect of smart people who can make things better than others! It's so hard to find an affordable, efficient and handy charger. As well not many people review those available online. Your videos are so easy, straightforward and informative, I like them! In case you have a few of those chargers and sell them I would be happy to buy one or even 2 or 3 of these if this is more attractive for you. If you can make an efficient version for a 6v panel with 5.4 to 4.2v output (or whatever the usual USB range is) then I would also be very grateful to be able to purchase one of those. I use a 6v panel daily whenever I am living in the forest without electricity which is usually several months a year. Looking forward for your reply! 😊