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Discouraging results on Bluetti EB240

Matmo46

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Oct 16, 2021
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I recently bought a Bluetti eb240 solar generator. I was completely satisfied with it until I did a capacity test. Of it's 2.4kwh of claimed capacity , my Kill A Watt meter only metered 1.67kwh. unit was charged with solar until fully charged and auto shut off. And it was powering a 80 to 125 watt led television until auto shut off.
I understand that there is loss due to inverter inefficiency but this is 31% loss if it had a true capacity of 2.4kwh. that seems excessive even for poor quality inverters.
Has anyone else had issues with this unit. ?
Should I contact Bluetti for a return or is this standard to only get 69% of what you paid for..
 
Hobotech has a review of the EB240 where he pulled 85%.


Will has a review of the EB150. He was able to pull 95% of the 1500 watt hour battery. From what I understand, the EB240 and EB150 use the same type of cells.

I would definitely contact Bluetti about this.

I just ordered two refurbished EB240's from Maxoak. If they only pull 69% capacity I would not be happy, but considering the refurbished price I wouldn't be too upset. Not making any recommendations because they haven't arrived yet. Here is the link if anyone else wants to gamble on this. Appropriate because they are being shipped from Las Vegas. https://maxoak.net/pages/reburbishe...DrW0v8QQ1zf58mxccQfo8q-80oFjSlzaNfr-LYWxWyK4c

Anyone else have experience with these refurbished units? TIA
 
Hobotech has a review of the EB240 where he pulled 85%.


Will has a review of the EB150. He was able to pull 95% of the 1500 watt hour battery. From what I understand, the EB240 and EB150 use the same type of cells.

I would definitely contact Bluetti about this.

I just ordered two refurbished EB240's from Maxoak. If they only pull 69% capacity I would not be happy, but considering the refurbished price I wouldn't be too upset. Not making any recommendations because they haven't arrived yet. Here is the link if anyone else wants to gamble on this. Appropriate because they are being shipped from Las Vegas. https://maxoak.net/pages/reburbishe...DrW0v8QQ1zf58mxccQfo8q-80oFjSlzaNfr-LYWxWyK4c

Anyone else have experience with these refurbished units? TIA
Those prices are sketchy as hell. I wouldn't roll those dice. Is probably a straight up scam. I would be surprised if anything shows up.. however if Bluetti is selling low capacity generators they may be getting over run with returns and just want to get their money back out of it.
 
Those prices are sketchy as hell. I wouldn't roll those dice. Is probably a straight up scam. I would be surprised if anything shows up.. however if Bluetti is selling low capacity generators they may be getting over run with returns and just want to get their money back out of it.
Could be a scam. Wouldn't be the first time. I'm in another group that posted the link. Another member received two EB70's. He said one was good to go but the other was DOA. The EB70 and AC 200 were also posted but were sold out. The listings are removed from the updated web-page. Hoping the fact they removed the sold out units is an indication it's not a scam. The AC200 was $600.
 
I understand that there is loss due to inverter inefficiency but this is 31% loss if it had a true capacity of 2.4kwh. that seems excessive even for poor quality inverters.
While not for a moment suggesting it's good, inverter efficiency is generally pretty poor at low loads.

What is the self consumption of the unit? If it's ~40W (say) then there is your missing capacity.

Can you do a capacity test at a higher discharge rate? Say ~1000W 750W.
 
While not for a moment suggesting it's good, inverter efficiency is generally pretty poor at low loads.

What is the self consumption of the unit? If it's ~40W (say) then there is your missing capacity.

Can you do a capacity test at a higher discharge rate? Say ~1000W 750W.
I'm wondering if it is small loads over longer period increases invertor losses. I noticed when Will and Hobo tested them they were pulling much larger loads over much shorter time. I don't know about the parasitic losses. I don't even know how to test this. I did notice the fan kicked on for a second every couple minutes, which seems like a flaw to me because it's not hot, and it is not on long enough to make a difference in cooling.
After wall charging thru meter the capacity seemed closer to what it should be and I'm running another capacity test with bigger load.
 
Here is the thread about the Renewed Bluetti.
 
I'm wondering if it is small loads over longer period increases invertor losses.
Well the inverter will have a base level of self consumption. I do not know what it is. It may well be variable.

If it's say 40W (I have no idea, it could be 10W) then:

If your loads are low, say 100W (let's ignore the DC to AC inversion losses - go with me here), then 140W are being drawn from the battery, which will last 2400Wh / 140W = 17.1 hours.
In that 17.1 hours you only get 1710Wh delivered to your load.
Apparent efficiency: 1710/2400 = 71%

But if your load is 500W, then you are drawing 540W which will last 2400Wh / 540W = 4.44 hours.
In that 4.44 hours you get 2220Wh delivered to your load.
Apparent efficiency: 2220/2400 = 92.5%
 
In addition to the conversion efficiency and self discharge issue, the Bluetti Kwh capacity assumes a resistive load with a power factor(PF) of 1.0. Likewise, the Kilowatt assumes this as well. To simplify, when the PF is not one, the current and voltage drawn by the device are slightly out of phase and will not be read correctly (usually low) by the Kilowatt .

Modern switching power supplies in consumer electronics are notorious for not correcting power factor. This is also an issue for motors like the compressor motor in a fridge. Instead of depending on the Kilowatt, multiply the watt reading on the back of the TV by the runtime and see what you get. Also, I suggest you do a test with something like a space heater or toaster and check the numbers again.
 
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I ordered the EB70 as renewed as a "try" and lose $226. vs the high priced AC200p if it is junk . Well, it arrived with no cables or AC charger and a flat battery so we have no way to even charge it. I am waiting for a reply from Maxoak. There is a sheet of paper inside that has a date 10/5/2021 , no need for repair and I assume a serial number. Owners manual envelope looks new, the unit looks great as far as no marks or scuffs.

I had hoped the low pricing was just to clear out returns with all the new models out now. I was going to try a EB150 or 240 if this worked out seeing the AC200p sold out. I will follow up if I ever get it charged. I don't see the solar connector (DC7909 to MC4) sold on either site.

Afterthought I had after order was shipped; I knew no refunds but that I could get 3 replacements within the 1 year warranty. Wouldn't the shipping charges chew up any savings if customer has to pay? Maybe the reason such low prices and I regretted I forgot to check before jumping on what I hope was a bargain.
 
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Capacity test on my EB240 using 500W space heater = 75% (1.8 KWH as measured by Killawatt) . Not too happy with that based on Hobotech's video where he got 2.1 KWH.
 
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Capacity test on my EB240 using 500W space heater = 75% (1.8 KWH as measured by Killawatt) . Not too happy with that based on Hobotech's video where he got 2.1 KWH.
What did it have for a charge when it arrived? These don't meet the definition of renewed to me. I took it to mean tested and repaired to like new. 2 days of no response on lack of connectors and charger. I'd buy one if I was sure it fits, not finding any that say DC7909 to MC4. Thought maybe 8mm was the same then someone said "no" didn't fit right in an Amazon review.
 
What did it have for a charge when it arrived? These don't meet the definition of renewed to me. I took it to mean tested and repaired to like new. 2 days of no response on lack of connectors and charger. I'd buy one if I was sure it fits, not finding any that say DC7909 to MC4. Thought maybe 8mm was the same then someone said "no" didn't fit right in an Amazon review.
I didn't check the state of charge when it arrived. 8 mm is the correct size for the charger.
 
I'm more nervous thinking someone burned something up and it won't work. I finally heard from them the parts are going to be sent.

Charge read zero but the light worked though I turned it off quick in case a tiny charge remains. It's too heavy for a flashlight anyway ;)
I ordered DC connector from Amazon, figured an extra wouldn't hurt and will be here quicker.
 
Ordered two refurbished EB240's. Received them on 12/1/21. One was DOA. The other seems to work fine. It had two bars when it arrived. I compared the packaging on the two units. The unit that worked looked like it was packed by the factory. The power cord for the charging brick still had the plastic prong protector, the warranty sheet was in a plastic sleeve, and there was a card "Keep unit out of direct sunlight." The packing for the unit that was DOA was missing the card, the warranty sheet was not in a plastic sleeve, and the plastic prong cover was missing. The total for both units was $1040 or $520 each, free shipping.

Contacted Maxoak about a return for the DOA unit yesterday on their website chat. I also sent them an email 12/2/21. A few people in the Bluetti Facebook group have complained about slow and no response regarding returns.

The unit that does work took a full charge then turned off. I haven't had a chance to run a capacity test. I will do that tomorrow with the 150 watt capacity tester with the purple fan I've seen both Prof Hobo and Will Prowse using. 2400/150 is 16 hours. I guess it will take up most of the day.

I also have a Kill-a-Watt and a 500 watt space heater I could use. That would speed things up.
 

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Capacity test on my EB240 using 500W space heater = 75% (1.8 KWH as measured by Killawatt) . Not too happy with that based on Hobotech's video where he got 2.1 KWH.
Ran a capacity test using a small space heater. Kill-a-Watt showed 400w at startup and eventually reached 720w when the heating element reached a stable temperature. I used a Wyze cam set to 3 second interval time lapse for 4 hours. Video showed 1.81 before the LCD went blank. Will uses 0.9 as a factor for inverter loss. 2400*0.9=2.160 kwh. 1.81/2.16 = 83.79%. Without factoring the inverter loss, I get the same numbers as you. 1.81/2.40 = 75.4%.

I ran the same test with a refurbished EB150. Pulled 1.23kwh. 1500 * 0.9 = 1350. 1.23/1.35 = 91.1% Without factoring the inverter loss,
1.23/1.50 = 82%.

For what I paid for the refurbished units, I can live with these numbers.
 

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Any updates on this, re: return policy for the DOA, and performance of the good EB240? Thanks!
 
Hi everyone. Would like to add to this forum. Please keep in mind I am new and I am not super knowledgeable in electrical. Just starting to learn. I just got a refurbished EB240 and I also did a load test comparable to HOBOTECH. DC load test and I am getting 1900wh or 79%. I assume everyone else that’s was talking about their heater and machine load test used the DC port ? Because the AC ports have a major loss in inverters for sure. That being said, I was micro analyzing hobotechs video and when he was a doing a max load DC test I was seeing his tester machine read 118W being pulled while the eb240 was registering 109W. Mean while I am using a very similar DC load tester like his, where my system is registering 130W load on the tester while the EB 240 is saying 135w pull. So now i am very confused. Not sure how his dc tester was registering more than the eb240 presented, which could account for his high capacity reading. Also i hope everyone has been DC load testing because the AC loads are abismal in most portable batteries.
 
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