EB70S Parallel Solar Panels?

Total newbie to Bluetti products here, I just ordered an EB70S and the PV200 to charge it. Looking into the specs, I see that I have a 200W maximum input - but is this maximum for the unit in terms of charge rate, or is this maximum possible attached without something exploding?

My initial intent was to parallel connect the PV200 and my Jackery 100w so that I could actually be getting the full 200W to the unit under less than ideal conditions, but is attaching 300w worth of panels on the 200w maximum input going to let out the magic smoke when the sun comes out from behind the clouds? Or will it just use only what it needs? I’d think that excess amperage just won’t be used by the charge controller, but this is a rather expensive piece of kit to risk on a guess.

2 Likes

You can exceed the maximum power going into the unit, so you are correct you can exceed the amps but NOT the voltage. This is done all the time and is called overpanelling. I’m running 975W into my AC200MAX even though the maximum it can use is 900W.

However, do note, if you mix different panels in parallel the amps will get added but the voltage will max out at the LOWEST max voltage of either panel.

This means that the panel with the lowest open circuit voltage will control the max power output and, as such, you may not actually get 300W max even though you have a 200W + 100W.

This is why it’s usually better to use all the same types of panels.

1 Like

Ah! Thank you very much. I didn’t know about the voltage dropping to the lowest, I figured it would end up somewhere in the middle, as the higher voltage panel boosted the average in the parallel set. I’ll have to test it out and see how its real-world performance is!

In this case, I started with the Jackery setup (Jackery 300 and 100w panel), so I’ve already got that panel on hand and have been using it for a couple years with good success. Figured as long as I had it, I’d like to be able to use it to get closer to the max charge rate - as long as I didn’t do something stupid and throw in 50% more juice than the charge controller could handle somehow. Wasn’t sure how… but I’ve let the magic smoke out before, and you get a bit twitchy! lol

So, rather interesting as I play with it!

Connecting just my Jackery Solar Saga 100 - 95 watts input shown.
Connecting just my PV-200s - 147 watts input shown.

Connecting both in parallel… 153 watts input. The heck in a handbasket? 300w of cells, and I can’t even manage 2/3ds of theoretical, with one of them putting out 95% of theoretical? I’ve gotta say I’m a bit underwhelmed with the PV-200s results, given the Jackery cranking out 95% of theoretical in the same conditions that the Bluetti is having trouble even reaching 75%.

You’re hitting the max amps of 8.5 for your EB70S.

I had the same thing happen with my EB3A (before I broke it), but it’s easily explained because the EB70S and EB3A both use the same MPPT chip which supports 12-28V at up to 8.5A. Your panels’ voltage are likely going down to around 18V so with the 8.5A max that’s 18V x 8.5A = 153W. To reach the 200W max input your voltage would need to be 200W / 8.5A = 23.5V which isn’t practically possible with most solar panels so for most people ~150W is the practical max watt input for the EB3A, EB55 and EB70 when using solar.

2 Likes

Hmm, that’s kind of annoying, especially because apparently they both have almost no over-voltage protection, so paralleling two 18v cells is right out. Sounds like a single 200w cell is about the largest practical amount of cell I can put on effectively. I should have picked up a second Jackery 100w instead of the PV-200, I think, since it’s MUCH easier to move. Guess the extra gives me a bit of a benefit in hazed sunlight or such.

I’m kind of starting to regret I didn’t get the EcoFlow River set I was looking at, I keep running into “Oh…” moments with the EB-70S.

Exactly, yes.

I just upgraded to an EB150 which supports 16-60V @ 10A for 500W max solar input. I’m running four 100W panels in 2S2P (2 series, 2 parallel) configuration (source):

That does look pretty darn good, I should have really done a bit more research before I bought, I would likely have chosen either a different model or a different brand. Not being able to charge rapidly on solar is kind of a fairly significant handicap on my plans for the unit, I was hoping to be able to run 300w of solar to get the full 200w input, and charge it in ~5 hours of sunlight. As it stands, it kind of looks like it’s going to be a full-day affair to charge it.

i’d like to do the same thing but with AC200P and 3 PV350 panels.
AC200P supports VOC 35-150V, 12A and the PV350 is VOC 46.5V, 9.2A
so 3 of them should be under the limit and may safely max out the 700W limit.

does this sound safe?

@lschiedel this is a bit tricky with 3 PV350 panels and your AC200P.

Wired in series, the combined Voc of the three PV350 panels would be 139.5V which is fine during the summer but would increase in the winter season bringing it very close or even over the 150V max which you do not want to exceed. If unsure, always measure the open circuit voltage in full sun before connecting it to the station.

Wiring the panels in parallel, however, will not be efficient because you’ll easily max out the 12A input of the AC200P and likely won’t be able to get more than 500W solar input but it is much safer as you’re not close to the maximum input voltage range.

If you want to be on the safe side, grab yourself a Bluetti D050S charging enhancer for the third panel and wire the 2 other panels in series to the AC200P via MC4 → XT90 → Aviation Plug.

Here’s a summary table:

PV350 Configuration Voc (Open Circuit Voltage) Vmp (Max Power Voltage) Imp (Current at Max Power) Usable Imp (Current at Max Power) Estimated Usable Input Watts
3 Series into AC200P 139.5 112.5 9.2 9.2 700
2 Series into AC200P 93 75 9.2 9.2 690
3 Parallel into AC200P 46.5 37.5 27.6 12 450
2 Parallel into AC200P 46.5 37.5 18.4 12 450

If you use the D050S charging enhancer the recommended setup (2 series into AC200P and 1 panel into the D050S) then you’ll get up to 690W via the Aviation input port and up to 350W via the D050S via the AC input port for a total of around 1040W max in perfect conditions.

To reach the 200W max input your voltage would need to be 200W / 8.5A = 23.5V which isn’t practically possible with most solar panels so for most people ~150W is the practical max watt input for the EB3A, EB55 and EB70 when using solar

bxm6306 - thank you very much for this explanation. I’ve been confounded by the EB70S specifications which claim a max PV Input of 200 watts but allow no more than 8 amps of current.

It is a bit deceptive for Bluetti to claim 200 watts of PV Input on these models when 150 watts is a more realistic value given (1) the limitations of the MPPT chip they selected, and (2) typical operating voltages of most 200 watt panels.

I’m intending to pair my new EB70S with a Renogy 12 volt 200 watt panel with a max current rating (Imp) of 8.85 amps. Do you know if I will fry my EB70S by exceeding the 8.5 amp limit on the MPPT chip? If there’s a risk of frying the EB70S, can I reduce the current by simply installing a longer cable (i.e. more resistance) to the panel?

Hi @MikeOnline , High current will not fry your EB70S, please don’t worry. It will only if the voltage is too high.
According to your solar panel parameters, it is compatible with our EB70S. Please feel free to use it.

1 Like

@MikeOnline like what Bluetti said, supplying too many volts is a problem from your panels to the power station, but since amps are requested/pulled from the power station, it will never exceed its maximum amp rating of 8A, even if the panels could supply more.

Yeah, I was not too overjoyed at all when I found out that the “200W” charging was really 150W plus some marketing smoke. Particularly when I passed up a good deal on an EcoFlow River for the EB70S. Ah well, live and learn. I’ll likely end up needing to buy something else that will charge faster eventually, but this is a good storage solution when I have tons of time to charge it up on solar.

@Komitadjie to be fair though, 150W of solar will still charge your EB3A in under two hours: 268/150 = 1.78 hrs. With the full 200W of input it would be 268/200 = 1.34 hrs, so just a half hour difference which is not the most egregious marketing trick I’ve seen.

I’m using an EB70S, though, not an EB3. Takes a fair bit longer.

At the rated 200W, it’ll charge in 3.58hrs

At the real 150W, it takes 4.77hrs.

Considering the number of peak solar irradiance hours in a day, that extra 1.19hrs, fully 25% of the listed time, is a fair bit! I don’t consider it a crippling issue by any means, I’m just kinda put out by the marketing fine print, I feel vaguely screwed on my expectations.

Now if only they made an enhanced/smaller version of the D050S that could reduce the voltage down to 23.5V
(would be good to protect against over-voltage too)
(would even let us plug in a b230 into an eb3a or eb70s).

are there any third-party boxes that can do that?

1 Like

Now that’s something that would most definitely draw my attention! And likely my cash as well.

It is technically not a lie, just hard to practically achieve in real-world settings. Increasing the max amps by a few figures would be another alternative without having to increase the input voltage range.

All of this said, I do have to give Bluetti credit for the EB3A because I don’t know many portable solar power stations of this size (aside from the Ecoflow River 288Wh) that even accept up to 200W of solar input. The Jackery 300 accepts up to around 90W of solar input, the GoLabs R300 (and most other no-name brands) up to 60W. The EB55 and EB70 ought to have upgraded MPPT controllers given the larger battery, I am disappointed in that.

Indeed, that’s why I specified it as “marketing fine print.” I was unfortunately unaware that I had to look for that on these, I’ve learned a bit here! They technically were not lying - just shading the line pretty hard. Sure, your brand-new, well-marketed refrigerator will cool 25% faster!.. if you run it on 160VAC. xD

Yeah, my attraction was the LiFePo cells, as opposed to the LiIon, and the high rated charge, since I figured I’d just parallel a bunch of cells to get to full rate, and be able to charge up fast and easy. I’m really surprised they didn’t put a better controller in them, that’s just kinda disappointing. It seems great for the EB3 and just a couple hours of charge time! On the larger batteries, though, it’s kinda underwhelming. It IS faster than the cheap stuff, though. It damn well better be, though, given that it costs a ton more than the “no names” too. I’ll happily pay for quality on a system!

2 Likes