Dead Brand New Bluetti EB150

[myrkr]

Hi all!

At the beginning of this year I purchased an EB150 through Amazon. Upon receiving the unit I plugged it into the charger and all was fine, display came on and it charged up. Then I plugged a small mini fridge into it for a test. The panel read something like 200w for the first couple of seconds as the compressor came on, then quickly fell to about 40 watts while it ran. This was all well below the max output so I let it run for about an hour. I came back about 30 minutes later to find the unit off. Screen was totally off and wouldn't turn back on, and the AC output was shutoff. I tried a whole sequence of pressing buttons on and off and nothing worked, the unit would not show any signs of life. Talked to Bluetti and they said it was most likely dead and sent a replacement and said not to worry about sending the other one back. Fast forward like 9 months to today and I'm just wondering if there is a way to open the unit up and do some troubleshooting inside to try and find what is the root cause, and possibly fix it. I've repaired and upgraded power supplies before, taking them apart and desoldering and soldering on capacitors, so I'm fairly comfortable opening it up to inspect and being safe. Was just wondering if anyone had any experience or ideas where to look first?

Thanks

 

[Supervstech]

Look into videos tearing down the unit.
I think Will did one...

 

[Supervstech]

if nothing g else, odds are good the batteries are good, likely a bms failure.

 

[Supervstech]

I jave a buddy that is planning a trip from your area down to nine soon, lemme know if ya wanna have me tear it down.

 

[myrkr]

Thanks! Okay, I'll check the videos and have a peek inside to see if there is anything obvious that stands out that I could fix. If I can't find anything, and the timing works out, I might take you up on that offer and send it your way to have a look.

 

[myrkr]

Just getting around to taking this apart and I've searched on Will's channel for a teardown, and then on the internet/Youtube and I can't seem to find any teardown videos at all for the Bluetti EB150. Anyone run across one? Here's an initial pic of what it looks like with the front of the case off.

 

[Forbisher]

Just getting around to taking this apart and I've searched on Will's channel for a teardown, and then on the internet/Youtube and I can't seem to find any teardown videos at all for the Bluetti EB150. Anyone run across one? Here's an initial pic of what it looks like with the front of the case off.

Will did not do a tear down.
JehuGarcia may have.
I know he did on the AC200 and Delta 1300

 

[myrkr]

Thank you! Just looked through all of JehuGarcia videos and found it!

 

[myrkr]

Took things most of the way apart. Don't see anything super obvious visually. However when I measure across the (60a) surface mount brick fuses on the BMS I get no continuity like they are blown, though visually they appear fine. I'm not familiar with these types of fuses though so I don't know what I'm looking at really.

If those fuses are blown, I'm assuming something else is majorly wrong somewhere and just replacing the fuses isn't gonna fix anything as they'll just blow again. Any thoughts or ideas?

 

[Supervstech]

Yeah, if all you had on the unit was a 40W load, and the unit seemed to handle the startup fine, only thing other than dead board is, the cells may have dropped quite low, and the compressor rapidly restarting repeatedly may have overloaded the output... maybe the battery voltage dropped right at the minimum, and then the compressor hammered the unit...

That might have popped the 60A, then he other one followed rapidly...

I’d solder on a maxi fuse holder, and drop in an 80amp fuse, and see what it does.

 

[Supervstech]

Reassemble the BMS, and check the charging and discharging ports see what voltage you have.

 

[Supervstech]

Those are the explody type of pouch cells, so, BE CAREFUL around them. A puncture, over discharge, or overcharge can start a raging fire...

 

[myrkr]

Thanks for the info!

Rechecked the fuses and realized I just wasn't getting penetration and had to push harder/scrape the surface and was able to check them. The fuses are good.

Checked the voltage at battery positive and battery negative (where the BMS is connected) and got 16 volts.

 

[Supervstech]

How about the output side of the BMS?
Both charging and discharge sides.

 

[myrkr]

When I measure positive at the battery positive, then measure negative at charging (C-) and at discharge (P-) I get the same 16 volts at both of those locations. Are those locations for negative (C- and P-) the right spots to measure?

 

[Forbisher]

When I measure positive at the battery positive, then measure negative at charging (C-) and at discharge (P-) I get the same 16 volts at both of those locations. Are those locations for negative (C- and P-) the right spots to measure?

I think its a 40ish Volt battery.

 

[myrkr]

I think its a 40ish Volt battery.

The teardown video by JehuGarcia has him saying it's a 4s3p configuration with 3.7v cells for a nominal of 14.8 volts. Does that seem right?

 

[Forbisher]

The teardown video by JehuGarcia has him saying it's a 4s3p configuration with 3.7v cells for a nominal of 14.8 volts. Does that seem right?

Dunno
Look at the Bluetti website specs and at your EB150 charger voltage.
14.8V battery sounds way too low but I could be way off.
The Jackery's are about 24V and the Bluetti AC200 is 52V

 

[myrkr]

Dunno
Look at the Bluetti website specs and at your EB150 charger voltage.
14.8V battery sounds way too low.

Good thinking! Just checked the Maxoak site and it lists the battery spec as...

"LG Li-ion battery cell, 101,351mAh/14.8V( equivalent to 405,405mAh 3.7V))"

The charger itself thoug h is 42V, but I think that's just the max voltage input.

So my battery measurement was 16.15V, is that possibly too high if the nominal is 14.8V?

 

[Supervstech]

Good thinking! Just checked the Maxoak site and it lists the battery spec as...

"LG Li-ion battery cell, 101,351mAh/14.8V( equivalent to 405,405mAh 3.7V))"

The charger itself thoug h is 42V, but I think that's just the max voltage input.

So my battery measurement was 16.15V, is that possibly too high if the nominal is 14.8V?

4.2V per cell is 100% full, so 16.8 would be the max charge... 16 should not be overcharged.