I should think it will work in practice, too, and having some panels in parallel will help the whole array perform better on overcast days, plus any shade that falls on one cell of one series of three panels will not be a detriment to the other series of three. Happy cabling!
Bluetti solar panel confusion
- Thread starter Fredh
- Start date
That will work but on cold sunny days under 30° your Voc will increase exceeding 67V so giving an error code and shutting off charging.
Good to know. If that happens i'll throw a charge controller on.
What's the Max Voc of any one of his Renogy panels?
In any case, adding panels in parallel won't increase the total Voc, but rather the current. In other words, he could experience an Error 17 even with his original 3 panels in series on a cold, sunny day, right?
max voltage is 21.6, and with the length of cable i have the voltage drops a bit to tap out at 59 currently.
Does anyone else get zero watt inout on cloudy days? in sun it charges great, when cloudy it shows nil. Possibly its trickle charging and doesn't show it, or its really doing zilch on cloudy days?
Does anyone else get zero watt inout on cloudy days? in sun it charges great, when cloudy it shows nil. Possibly its trickle charging and doesn't show it, or its really doing zilch on cloudy days?
Thanks for the Max. Voc spec.
The next time it's cloudy enough to see no charging at the Bluetii, I strongly suspect that pulling the plug and carefully measuring the voltage at the 8mm plug will show something less than 16V.
Whenever the voltage reaches 16V, the Bluetti will show at least a few watts of input.
Switching in another three panels in parallel, at that moment, would double the watts displayed, but the voltage would remain identical.
Adding panels in parallel cannot raise the voltage to reach the minimum required 16V in poor light. But adding parallel panels will double your charge rate even in light that's just good enough to achieve 16V.
The next time it's cloudy enough to see no charging at the Bluetii, I strongly suspect that pulling the plug and carefully measuring the voltage at the 8mm plug will show something less than 16V.
Whenever the voltage reaches 16V, the Bluetti will show at least a few watts of input.
Switching in another three panels in parallel, at that moment, would double the watts displayed, but the voltage would remain identical.
Adding panels in parallel cannot raise the voltage to reach the minimum required 16V in poor light. But adding parallel panels will double your charge rate even in light that's just good enough to achieve 16V.
just tested it and i'm getting 59 volts but still reading zero watts.
OK, I'm stumped.
And you're saying that if you just left everything as is, if the cloudcover cleared, it would start charging?
Don't get too worried yet, until you've shared this with Bluetti support, but to me, it sounds as if the MPPT charge controller is failing to react to the low current flow that's coming in at an obvously in-spec voltage.
Then again, there might be an unpublished minimum amperage (unknown to me, at least) that the MPPT requires, meaning there might be nothing wrong with your Bluetti, whatsoever.
They're known to offer good support, so try asking them if the MPPT has a minimum amperage requirement that would explain no charging, despite 58V on a cloudy day.
Remember, shading or cloudiness has very little impact on voltage coming from the array. I impacts amperage. And if you had another series of 3 panels in parallel. the amperage would double, possibly reaching that unpublished minimum amperage threshold, for those conditions.
Please let us know how it goes.
Yes, to answer your first question. While i was watching the watt meter on the unit the sun cleared the clouds and as soon as the sun hit the panels the meter went from zero (with 64 volts, which failed to trip the overcharge code, hope thats not cutting it too close!) to 40 watts and then on up from there. So it looks like 40 watts may be the minimum the Bluetti EB150 will charge at, or the oanels dont produce any amps until they're in the sun. i Ordered another three panels to run in series/parallel and when they arrive ill let you know how it works out.
Sweet! Thanks for this update.
Going by some Hobotech videos I've watched on YT, there's about a 10% difference between Amps going into the EB150 and Watts displayed as input, due to controller losses. The Bluetti is displaying the actual Watts being delivered to the battery, after controller losses.
So, if you're seeing 40 watts on the display, you've probably got 44.4 Watts coming from your array, at 64 Volts.
Dividing 44.4 Watts by 64 Volts, the EB150 is basically trickle-charging at only 44.4/64 = 1.44 Amps. We can't complain about that, I suppose.
Don't worry about coming too close to the 67V maximum Voc. It's a Pass/Fail thing. Not a problem at 66.9V. And even if you exceed the threshold, there's no harm done other than finding out later that it posted an Error 17 and you haven't been charging when you thought you were.
Just turn off the Bluetti and turn it back on to continue charging.Thanks for sharing your experience here. You're sort of trailblazing for other EB150 owners. And thanks for ordering another three panels with intent to let us know how that performs! I'm really looking forward to that, even though I've seen a Hobotech video where he demonstrates setting up six panels for the very same reason - charging the Bluetti EB150 on cloudy days.
I have an EB240 that will accept 68V (instead of 67V), but I'm theoretically in a worse situation than you, in that I have three BougeRV 180W panels in series, each of which has a Voc of 23.84V, for a potential total Voc of 3*23.84V=71.52V. That's 3.52V over the EB240's maximum permissible 68V. Oddly, I've never seen an Error 17.
My fear is that sooner or later, it's going to be cold enough outside or the skies clear enough or the panels angled perpendicularly enough for the Voc to exceed 68V. (I didn't know what I was doing when I ordered the panels - and I'm still learning, of course. In hindsight, I should have ordered three 175W panels.) Then again, panels are known to lose a bit of their photovoltaic efficiency in the first few days of use, so maybe that's what saved me.
Another trick that might work, if getting Error 17's, would be to insert some kind of resistor network to reduce the voltage a tad:
How to Reduce Voltage with Resistors
In this article, we will show how you can reduce voltage to any amount by using resistors in a voltage divider circuit.
www.learningaboutelectronics.com
Of course, that resistor network would always stifle my voltage, reducing the charge rate by a smidge on cloudy days as well as under ideal light. But... with another set of panels in parallel, exceeding the 500W total that the Bluetti can consume (when input amperage exceeds 10A), I could have my cake and eat it too!
I like the idea of springing for another three panels, as you've done, to get that improved performance in less than perfect conditions, Maybe what I should do is buy just one more 185W panel - and run a 2s2p array. Hmmm... That would bring the total Voc down from 71.52V to a no-worries 47.68V, while nevertheless increasing the ideal condition total Watts from 3*185=555W to 4*185=740W. The Bluetti charge controller will only pull 10A of the available 14.8 Amps, under ideal conditions, but that 50% excess amperage for ideal condtions, would be welcome under less than ideal conditions.
In your case, a little arithmetic says that your recent order of an additional three 100W panels to create a 3s2p array will take your array up to a potential 600W or 12A - 20% more than the 10A the controller can use, under ideal conditions. But even a light overcast will have you enjoying double the charge rate you're getting now, under those conditions.
I'm fairly new to this game, but it seems to me that none of these panels actually produce their rated wattage in real-world conditions, so the more the merrier! (But I've read we should never go more than 3 deep, in parallel - as the currents can become too high for the wire guages.)
Do let us know how things go with your system.
Here's hoping you have some cloudy weather soon after you trick out your array. So for a final update on my Bluetti EB150 with six Renogy 100watt monocrystalline panels (two series of three then joined parallel). In full sun i'm getting 64 volts (manual says the overprotection charge kicks in at 67) and the Bluetti tops out at 545 watts when charging, and everything is working fine!
Thanks to all of you who have participated and pioneered in this thread and helped me immensely in sussing everything out!
Adam from Watkins Glen, New York
Thanks to all of you who have participated and pioneered in this thread and helped me immensely in sussing everything out!
Adam from Watkins Glen, New York
Hey, that's great news. Thanks for this follow-up report. Your overcast charging should now deliver twice the Watts seen prior to adding another set of three panels in parallel (assuming there's enough light to get at least 40 Watts coming in (or there abouts) to bring the charge controller to life.
Don't feel any obligation to do this on my behalf, but for your own interest, it could be enlightening to catch the the Bluetti charging at only about 100 Watts under an overcast sky - then unplug one set of three panels, to watch the charge rate get cut in half (yet still high enough to continue charging.) That experience would prove that the expense of buying another three panels, serves you "rain or shine."
Hedges
I See Electromagnetic Fields!
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If PV panels are capable of producing more current than your charge controller can use ...
I keep saying, "Orient some PV strings towards 10:00 AM sun, some towards 4:00 PM sun"
The 90 degree angle will reduce peak current and watts to about 0.7 as much.
Most of the lost 30% of power will be made up for in more hours of production, a flatter power curve over the day.
That reduces cycling the the battery for daytime loads, and provides closer to full charge late in the day, starts recharging earlier in the morning.
That should give you more Wh for night time use.
I keep saying, "Orient some PV strings towards 10:00 AM sun, some towards 4:00 PM sun"
The 90 degree angle will reduce peak current and watts to about 0.7 as much.
Most of the lost 30% of power will be made up for in more hours of production, a flatter power curve over the day.
That reduces cycling the the battery for daytime loads, and provides closer to full charge late in the day, starts recharging earlier in the morning.
That should give you more Wh for night time use.
