There is some wiggle room with the over-voltage before it permanently breaks the input circuit. Maybe around 10-20% over? For my EB3A (rest in pieces) I could input 32V and it didn’t explode and would continue working fine with < 28V afterwards.
Edit: Fixed typo
I wonder how much of that is actual legit over-voltage protection, and how much was just using up the design tolerances in the components, though. There doesn’t seem to be any kind of active protective system or even a first-stage replaceable failure point to protect the charge controller. If you want to get close to the actual charge rate listed, you’re going to have to push dangerously far up the voltage scale, with an input source that varies madly based on changing environmental conditions.
I’m in the same boat as Komitadjie. I’m new to solar and recently purchased an EB70S and am now I’m looking for the best panel to pair with it and quickly realized I wasn’t going to be able to get close to 200W maximum solar charging limit with a 200W panel because of the 8A input limit. I got to thinking about the possibility of using a larger panel such as a 250w panel that has a little bit higher VMP.
The panel below is 250w panel and makes 250w at 23.83V and 10.51A. The EB70S will only pull 8A. Vmp 23.83 at 8A is 190w. With that said I’m guessing as the amps decrease so does the voltage, but I really do not know. Is there a way to calculate what the actual voltage would be with this panel at 8A?
https://www.newpowa.com/collections/rigid-solar-panels/products/250w-monocrystalline-solar-panel
| PRODUCT CODE | NPA250S-15I |
|---|---|
| Maximum power (Pmax) | 250W |
| Voltage at Pmax (Vmp) | 23.83V |
| Current at Pmax (Imp) | 10.51A |
| Open-circuit voltage (Voc) | 27.28V |
| Short-circuit current (Isc) | 11.09A |
| Temperature coefficient of Voc | -(80±10)mV/°C |
| Temperature coefficient of Isc | (0.065±0.015)%/ °C |
| Temperature coefficient of power | -(0.5±0.05)%/ °C |
| NOCT (Air 20°C; Sun 0.8kW/m² wind 1m/s) | 47±2°C |
| Operating temperature | -40°C to 85°C |
| Maximum system voltage | 1000V DC |
| Power tolerance | ± 3% |
| Maximum series fuse rating | 15A |
Two things:
Safely using this panel you may well be able to get very close to the 200W max, do let us know!
Yeah, my concern would be the high-end voltage range, we’ve seen demonstrated a fair number of times that there is very, very little if any over-voltage protection on the incoming side - and if there is, we haven’t gotten any definition of what it will mitigate and where it will catastrophically fail. We know 60V will go past the catastrophic failure point, but how much over that was? We don’t know.
If you do get it over 160W or so, for sure let us know! I’d LOVE to be able to actually charge mine at the rate that they advertise.
I see what you mean about potentially exceeding the max input voltage with the Newpowa 250w panel in cold weather. Does Bluetti publish any safety margins to the 28v max input? Just wondering if there is, for example, a 5v safety margin or something like that?
Newpowa does have a 240w panel with the following specs. This panel would give me a little more of a safety margin before hitting the 28v max. What do you guys think of this panel? It might get me a little closer to 200w.
| # PRODUCT CODE | # NPA240S-15I |
|---|---|
| Maximum power (Pmax) | 240W |
| Voltage at Pmax (Vmp) | 23.16V |
| Current at Pmax (Imp) | 10.40A |
| Open-circuit voltage (Voc) | 26.71V |
| Short-circuit current (Isc) | 10.97A |
| Temperature coefficient of Voc | -(80±10)mV/°C |
| Temperature coefficient of Isc | (0.065±0.015)%/ °C |
| Temperature coefficient of power | -(0.5±0.05)%/ °C |
| NOCT (Air 20°C; Sun 0.8kW/m² wind 1m/s) | 47±2°C |
| Operating temperature | -40°C to 85°C |
| Maximum system voltage | 1000V DC |
| Power tolerance | ± 3% |
| Maximum Series Fuse Rating | 15 A |
With 32V PV input my EB3A would not accept the voltage (the Input label would blink) but it doesn’t break the input circuit. I think just below 29V was the highest the MPPT controller would start pulling amps.
It’s all a balancing game. The closer you want to get to the 200W max input, the closer you have to get to the 28V max voltage input. That said, I think the 240W Newpowa’s slightly lower 26.71 Voc makes it only a little bit safer and you still should be able to get close: 23.16Vmp * 8A = 185W. Still, keep a close eye during winter.
Thanks @bxm6306.
I’m planning on running about 50’ 10 AWG MC4 extension cable between the panel and the EB70S. I’m guessing there will be some voltage loss with this long of a cable. Perhaps this voltage loss would offset any concerns about running this panel in cooler weather. Any ideas on the amount of voltage loss with MC4 extension cables?
I’m running 70 feet of 10AWG MC4 cable with no measurable voltage loss pumping 33V @ 8.7A. I carried my EB150 to my apartment roof to measure this first-hand. You shouldn’t see any noticeable voltage loss at that distance with 10 AWG.
That is good information. Thank you.
I also found these sites that calculate solar panel voltage based on the panels specifications and the temperature. I set each calculator to indicate a single panel. According to these calculators I’m only around 28v at 25 degrees with the 250w panel.
So I’m thinking I will be OK with the 250w panel as it doesn’t often get below 25 degrees around here.
Received my EB70S today. The 250w solar panel should be here around the end of the week. I’ll test it all out this weekend and let you know how many watts I’m able to pull with it.
I got my solar panel and cables setup yesterday and hooked everything up to the EB70S. It was a partly clouding day so not ideal conditions, but the sun did peek out now and then. After setting my panel to what I believe was a good angle I got input wattage of 170 watts from the panel. Not bad, but I’m hoping to get little better when conditions are improve.
One of the goals of the EB70S is to be able to run a small floor freezer 7 cu ft and perhaps a 18.0 cu ft standard fridge in the event of a power outage.
When I plug the small floor freezer into the EB70S I get nothing. The power light is lit on the freezer but the compressor never starts. No alerts on the EB70S.
When I plug the fridge into the EB70S on the first attempt to start I get an overload message, but if I reset the EB70S and try again it runs fine until it cycles again and then it overloads, reset, runs fine. I’m guessing there must be an initial startup load that is greater than 1400w, but I’m not sure.
I’m thinking I might have to go with a larger solar generator for my needs. If you look at the specs of both these appliances the EB70S should be able to run them just fine, but it reality EB70S appears to struggle.
Update: I’ve had my refrigerator running on the EB70S for about 2 hrs and no issues. So perhaps it will work after all. I plugged the solar panel into my EB70S and today it is pulling 177w. If I can get up to 180w that would be great.
It’s all about that startup surge and oftentimes it happens so quickly that your power station output display doesn’t refresh fast enough to show it. I have the same problem with my 8000 BTU AC and my EB150. You need to install a soft starter for it to reliably turn on but those aren’t cheap and require special knowledge to install.
Hi, I’m Giulio and I live in Italy, I’m inexperienced with bluetti and new to the forum and I need some help
I bought a Bluetti eb70 for Christmas (gift) to take on trips out of town. Not wanting to leave the Bluetti panel fixed on the roof of the defender, I limited myself to buying a 100w Renogy panel
panel features :
Maximum power 100W
Maximum System Voltage600 V DC (UL)
Open Circuit Voltage 24.3V
Short circuit current 5.21A
Optimum Operating Voltage 20.4V
Optimum Operating Current 4.91A).
I saw that the 190w (200w) panels all have a capacity of 9, or 10 amps, therefore higher than the bluetti’s capacity. What can I do to get closer to 200w?
if I use two panels like my 100w one, with a voltage of 20.4v, they would supply under maximum conditions (4.91ax2) x 20.4V = 200.3W
Right? Can you tell me that I can connect them to the Bluetti without causing damage? does the voltage stay the same?
thank you very much for helping.
Giulio
Ho letto tutta la discussione e cerco di rispondermi da solo.
Collegando un pannello da 170w con tensione massima di 18v dovrei arrivare al massimo a 153w,
poichè il Bluetti eb70 assorbirà solamente fino a 8,5 ampere.
giusto?
grazie
Just make sure your open circuit voltage is still within EB70 range VOC 12-28V when your solar panel is connected and it will work.
It doesn’t matter if the current is over
The maximum you will ever see no matter how many panels you connect will be in the 160 to 165 watt range in absolutely perfect conditions so keep that in mind. When connecting multiple panels (assuming you connect them in parallel) the voltage remains the same and the amps increase. You can connect higher amperage than the capacity as the Bluetti will only allow the maximum amperage and no damage to the unit will occur.
Hi orzowei,
The trick is to find a panel that comes as close to the max 8 AMP without going over the 28v max input voltage. I picked up a Newpowa 250w panel (details above in this thread) that came the closest that I could find. A few weeks ago it was charging my EB70S at 187w (see picture below). That is one of the highest solar charge wattages I’ve seen from this panel with my EB70S. I should note that it was cooler outside. The warmer it gets the less efficient the panel becomes.
thanks
Grazie mille!
Good selection. That is the highest wattage I have seen available for input.
