Voltage regulator for solar panel - Page 1
Forum section: electronics / general

author: wa4whl
author_rank: Newbie
timestamp: January 23, 2019, 06:04:12 pm
content: I'm rebuilding a regulator board for a solar panel array and unable to identify a regulator chip by the markings. The device is 8-pin surface mount with the markings SAQ 7BK A9S4. So far I've tried every combination and nothing. Any idea what this is?

author: nsrmagazin
author_rank: Regular Contributor
timestamp: January 24, 2019, 09:55:28 am
content: If you post a few pictures that will be very helpful for us. Is replacing the regulator circuit an option? its most likely a voltage and current regulator

author: Doctorandus_P
author_rank: Super Contributor
timestamp: January 29, 2019, 12:31:09 pm
content: What is the size (power / voltage / current) rating of your solar panel?MPPT charge controllers start from < EUR 10 from Ali / Ebay / China.For devices like that it is hardly worth rebuilding.https://www.aliexpress.com/wholesale?SearchText=mppt

author: nsrmagazin
author_rank: Regular Contributor
timestamp: February 05, 2019, 12:19:27 pm
content: I would recommend this one in particular:www.cfcbazar.com/products/oem-lcd-display-20a-mppt-12v-24v-solar-panel-battery-regulator-charge-controller-without-any-logo-on-surface-t20-lcd-wholesales/Its with high quality.

author: jonroger
author_rank: Regular Contributor
timestamp: March 06, 2019, 03:07:35 pm
content: Be careful, many solar charge controllers labeled "MPPT" are actually PWM. A 20A, 24V DC-DC converter involves a certain amount of cost and heat (ie, heat sinks).

author: george80
author_rank: Regular Contributor
timestamp: March 06, 2019, 09:23:14 pm
content: Quote from: nsrmagazin on February 05, 2019, 12:19:27 pmThat is NOT an MPPT Charger. it IS a PWM. I know, I have 2.I would agree they are good units BUT, they are not MPPT as a lot of online chargers so marked are not. Here one easy way to tell is if the thing sells for under $50. If they do, they are NOT MPPT. I was looking recently and couldn't find a genuine MPPT for under $70.Prices may vary in different countries but one thing is for sure, The cheapest MPPT starts where the most exy ( and over priced) Pwms start leaving off.Cheap MPPT's also start at 10A Not 20 or 30 Like PWM. If you are loooing at anything marked MPPT and it's 20A and in the same price range as other MPPTS, it's a PWM.There are loads of Pwm units MARKED as MPPT but best do a bit of research on Google and YT and find one that looks the same and see what it is. Model numbers change but as china produced stuff is all made to a formula, if it looks the same regardless of colour or markings, it IS the same.Googling Fake MPPT chargers and the same on YT will be helpful in sorting the the rip off con jobs from the real Mc Coy.All that said, PWM are not bad chargers at all and IF setup correctly can be real world just as efficient as PWM. It would pay to understand the difference and see if the more exy MPPT is actually needed and will give real benefits. For my purposes they would not and I have been very happy with the PWM's I have which allow me to pump much more power into a battery ( and direct to a load in the daytime) given I have the panel capacity than it would cost me maybe 10X more to do the same with an MPPT or a couple as I would need.

author: DTJ
author_rank: Super Contributor
timestamp: March 28, 2019, 12:07:02 pm
content: Just a note to be careful with the regulator linked to above. I used a similar one with a surplus roof top solar panel. The o/c voltage of the panel was a bit too high for the regulator when used in the 12V mode.It would work for a while then lock itself out. I tracked it down to me exceeding the panel Vo/c.I ended up shopping around for one that would handle the 50V o/c panel voltage.