To get started in solar, I purchased a Jackery Explorer 240 and the HQST 50 Watt solar panel that @Will Prowse recommends to go with it. I couldn't be happier with the Jackery, but the charging performance with the HQST panel is very disappointing. When the panel is first plugged in, the charge rate--according to the Jackery's panel and an inline meter--starts at 39W, but over the course of 30 minutes it drops to 11-16W (depending on the day) where it remains. This is with the panel pointed directly at the sun at mid-day under bright, cloudless sky here in the desert southwest. I've exchanged numerous emails with HQST, providing measured open circuit and operating voltage, and short circuit and operating current of the panel, and Jackery state of charge data. They maintain that the panel is in good condition and that the issue is with the Jackery's input circuit. I'm still learning about solar, but I would think even a PWM controller like what's in the Jackery would have better performance. HQST's customer service has been great, and they are sending me a shipping label to return the panel, so I have no complaints with the company. I just don't understand why the combined performance is so disappointing. Any suggestions on what panel might work better?
Jackery 240 + HQST 50 Watt Panel = Disappointment
- Thread starter Vizzini
- Start date
I started with the Jackery at 20% SOC
Here is some of the data that I recorded. The operating voltage and current were measured at the panel MC4 connectors before the adapter to the Jackery. The input power and SOC are from the Jackery's display. From the label, the panel optimum operating point is 17.6V at 3.12A.
11:04am 17.8V 2.2A => 39W 20%
11:09am 17.8V 1.7A => 30W 22%
11:14am 17.7V 1.5A => 26W 23%
11:19am 17.7V 1.3A => 22W 23%
11:24am 17.7V 1.1A => 20W 24%
11:29am 17.7V 1.0A => 16W 25%
11:34am 17.7V 1.0A => 16W 25%
11:39am 17.7V 1.0A => 16W 26%
11:44am 17.7V 1.0A => 17W 27%
11:49am 17.7V 1.0A => 16W 27%
11:54am 17.7V 0.9A => 15W 28%
11:59am 17.7V 0.9A => 15W 28%
12:04pm 17.7V 0.9A => 14W 29%
At this point I disconnected the panel and plugged in the Jackery's 12V adapter and got 38W input power. I then attached a bench power supply set to 17.7V in place of the panel and measured 3.2A of current and 56W input power. So, at least using a power supply, it doesn't look like SOC is contributing to the reduced charging performance.
I think I understand solar panel IV curves, but perhaps a guru out there can see something that I'm missing.
Bob142
Build more, learn more.
I've got two Jackery 240s and I have not seen them behave the way you describe. I use HQST 100W mono panels to charge them and get up to 65W sustained in full sun. It's been a while since I've tried a 50W panel but my recollection is that in full sun it would hold at 40W-ish. I've got nothing but clouds right now so I can't immediately double check for you.
I recommend to you and anyone else with a Jackery 240 to buy a 100W panel to go with it, if you can afford it. It's the only way to have a shot at recharging the Jackery 240 in a single day (at least where I live).
If you get a new panel and still get the wonky solar performance, you've got another variable in the input adapter. I've been using this one without issue. But maybe you've got a loose connection in yours? The final stop on the tour would be to contact Jackery customer support and supply them with all the information you've posted here. I've found them to be very responsive.
Good luck and keep us updated.
IIRC i got the full 65W charge rate up to 97% SOC and for sure was getting it below 95% SOC
What is your solar voltage under load? I bet its saging quite a bit.
If you can get your Voc, Isc, Voltage under load, and current under load
As Bob142 said it could be a bad adapter cable, try measureing Voc and Isc at the adapter plug where it would go into the jackery then do the same at the mc4 connectors of the panel, if they arnt pretty much identical the adapter is faulty
What is your solar voltage under load? I bet its saging quite a bit.
If you can get your Voc, Isc, Voltage under load, and current under load
As Bob142 said it could be a bad adapter cable, try measureing Voc and Isc at the adapter plug where it would go into the jackery then do the same at the mc4 connectors of the panel, if they arnt pretty much identical the adapter is faulty
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I purchased a HQST 100W monocrystalline panel (HQST-100D-SSP), and I'm now seeing reasonable charging performance. It's been overcast/cloudy/rainy here for the past week, but this weekend the sky was clear enough to test again. Under full sun conditions the Jackery was pulling 3.2 amps from the panel resulting in 57-62W charge rate. As clouds passed over, the operating voltage (measured at the array) remained constant while the current dropped, but once the clouds passed the charge rate recovered. Even with the partly cloudy sky, I was able to charge from 30% to full in about 4 hours.
Before I returned the 50W panel I did verify that I was seeing the same voltage and current before and after the adapter, and I repeated the measurements when I hooked up the 100W one. Based on these measurements and the good performance with the 100W panel, I'm calling the adapter good.
I've been looking at the voltage and current measurements between the panels, and I still can't figure out why the 50W panel performed so poorly while the 100W one provides the expected charge rate. The rated Voc is nearly identical (21.2V for the 50W vs 21.3V for the 100W), and the rated Vmp is very close (17.6V vs 18.0V). Connected to the Jackery, the operating voltage settled in at 17.7-17.8V for both panels. Current under load quickly dropped to 0.9-1.0A on the 50W panel as shown in my first post, while current was maxed out due to the Jackery's input limit using the 100W panel (unless shaded by a cloud). After sitting in the direct sun (no clouds) for 3.5 hours, the Voc for the 50W panel dropped to 18.2V, and after 4.5 hours under partly cloudy skies Voc for the 100W panel was 18.7V. Measure Isc for both panels during/after testing were consistent with their ratings. Unless the operating voltage was on the vertical part of the IV curve for the 50W panel and the horizontal part for the 100W, I can't explain what I've observed.
