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Getting more than 1500w out of an EG4 3000w and a single Lifepower4 48v

Thanks for continuing to come back with more info/testing as you try things.. I personally hate to see an electrical mystery left hanging.

I don't disagree that store-bought or factory-made wires are 'unlikely' to be a problem, but I also think it's 'unlikely' a 3kw inverter with a 1.5-2X surge capacity hooked to a 5kwh battery couldn't start a 14k btu or whatever it was, so we are already sort of in the weeds to begin with.

You can do the voltage measurements with a regular meter, it's just that a meter with min-max doesn't require you to be looking directly at it as the event occurs. It can turn '3 handed operations' back into 2 handed ones. :LOL: I understand the AC startup is a transient situation that doesn't even give the meter reading time to settle on the screen, so you may try just loading the inverter close to 100% with an ongoing load and then take the voltage readings at a less hectic pace, just to give an idea whether there is or is not a voltage drop issue in the cabling.
 
So we're at the campground and it's temperamental even with two inverters in parallel. Signs pointing back to the battery because when the charge is above 50% we have more successful starts than when it dips below 50%.

Charging off the generator works fine (Westinghouse 4500). Charging + AC is too much, even when charging is set at 20a.
 
ZeroZim said:
Charging off the generator works fine (Westinghouse 4500). Charging + AC is too much, even when charging is set at 20a.
Click to expand...
Yesterday this AC started off a Honda 2000... Now it's barely able to run on a 4500.

Very entertaining that you're doing things like stacking inverters but aren't able to take a voltage drop measurement.
 
ZeroZim said:
I have an EG4 3kw inverter and a single lifepower4 battery. It runs as a backup for the networking equipment in the house with a steady 500w load. We had the opportunity to borrow a travel trailer and I wanted to be able to have the AC after "generator hours" are over. So I dismantled the setup in the house and attached it to a hand truck to put into the trailer.

However, it won't run the AC. The battery goes into fault and the inverter reboots. I tried the firmware update that EG4 put out (the one with the lousy attitude in the video) and successfully updated it. Now it doesn't go into fault but it does restart. No error on the inverter that I could see. The battery specs clearly indicate that it's capable of 100a output, with 30 recommended. I just don't see more than 30a output.

My little Honda will start it, if Eco mode is off, so the surge isn't much more than 2000w. The generator doesn't even go into overload to do it.

Components:
12,500 BTU AC from 2019
Travel trailer with 30a input wiring
Honda EU2000i generator with 2000w surge, 1600w rated
LifePower4 5kwh battery 48v
EG4 3kw inverter

I'm sure adding another battery would be all the difference, but this is a temporary setup just needed through the end of the week. It's just frustrating to not get anywhere near the rated power out of the unit.

Any ideas for how to get this working?
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I run my travel trailer AC using my 100Ah 48V LifePower4 battery everyday without issue. I'm using a Growatt 3000 inverter however.
 
Koldsimer said:
What do you estimate the startup surge to be? Seems like a 48v 100a rated battery should be able to handle that. After all, the little honda 2000w max generator didn't trip anything when powering the same ac.
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The generator I am guessing has lots of energy stored in the flywheel.

They always say on shop vacs 5 hp 'peak' but the most a 15-amp, 120v outlet in a home circuit can supply is 1800w divided by 746 equals 2.41 hp.

My shop vac worked on a 700w harbor freight generator. I think that 5hp peak on a vacuum is some angular momentum in the motor getting used up.
 
Lilikoi_Heavy_Industries said:
Yesterday this AC started off a Honda 2000... Now it's barely able to run on a 4500.

Very entertaining that you're doing things like stacking inverters but aren't able to take a voltage drop measurement.
Click to expand...
Didn't get a chance to video it until today since we have other irons in the fire. It's a lot easier to throw the extra inverter in the trailer than it is to set everything up for a quick video.


The leads were connected to the battery. Voltage dropped to an indicated 10.6 volts at the battery when the air conditioner was switched on, rebooting both inverters.

>And what do your wires look like? Are they longer than the trailer is wide like this install features?

The difference in voltage drop for 6 feet of 4awg wire vs 2 feet of 4awg wire is .5% or 0.12 volts. It's a complete non-issue. In their permanent install, I'll be shortening them to the minimum reasonable, but there's no sense cutting up $40 cables for 3 days of use over 0.12 volts.

The Honda would start it without triggering an overload condition but clearly wasn't thrilled about the load.
The 4500 starts the AC without complaint.
The 4500 doesn't like to be charging this battery at 20a (2400v load), and start the AC at the same time. That triggered overload on the generator. Then the load switched to the inverters, which also failed to start the AC and rebooted.
The one inverter can never start the AC.
The two inverters will start it occasionally.

Either way, unless there's something else to try, I'm done stressing this battery. We're doing AC off of the 4500 during the day and only using the battery to charge our devices overnight. Thankfully it's mild weather.


I'm disappointed because I had expected to be able to have the rated wattages from these units.
 
The 3 Cruiseair AC units on my boat have a feature where they can be programmed on the thermosats control with different delays so all 3 compressors don't hit at the same time if they are powered up at the same time.

1660316070416.png

A little off topic I guess but this is very useful in not triggering overloads,
 
JLBinTN said:
The battery-to-inverter cables are 36" 2 AWG. The inverter AC out cable is 10 AWG and 10', and plugs into the RV cable which is also 10 AWG, and roughly 30' in length.
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Exactly.

My 3000VA inverter from a Tier1 manufacturer calls for minimum 2AWG no matter how short the wire is (0 meters even).
 

Cut the 3' 2 gauge cables in half and used the 18" lengths to connect directly to the battery terminals. It still drops down in voltage (23.3v lowest observed at the terminals) and the inverter restarts. This has been today's episode of "Wasting time on disingenous people".
 
ZeroZim said:

Cut the 3' 2 gauge cables in half and used the 18" lengths to connect directly to the battery terminals. It still drops down in voltage (23.3v lowest observed at the terminals) and the inverter restarts. This has been today's episode of "Wasting time on disingenous people".
Click to expand...
Considering a standard 4AWG wire isn't even rated for 80A, it's a good change.

Are you wishing you had bought a higher quality inverter now? "oops"
 
Probably not.
If two inverters can get the job done, and still cost a lot less.
 
Uhh... I kinda feel like people talking about the inverters are getting paid by a battery distributor to run interference.. WHAT?!

A ~12k btu/hr non-inverter AC probably does about 1300-1500w running. Figure 2-3x that for compressor start, with rapid decay. 3x 1500 is still within the surge rating of an (a single) HF 3kw inverter. Let's just say it is 4500w surge. 4500w / 53v shown on meter = 84a. Battery is rated by its manufacturer to do 100a continuously. As i said before, with a ~5kwh capacity it should not only be able to handle that startup surge, it should be able to handle that startup surge FOR AN HOUR STRAIGHT!

Lifepo4 battery voltage does not sag under load to any great extent, not even enough to trip low voltage disconnects unless your voltage was sitting right next to it to begin with. The only way the voltage reading and symptoms shown here happen is if the BMS disconnects the battery from the inverter. According to its own ratings, it SHOULD NOT disconnect under these circumstances because spec sheet says it will allow basically ANY current it is capable of, stated as ">250a", for at least one second. It should allow 150-250a discharges for 3 seconds, and 100-150a discharges for 10 seconds. Even if you talk about 'bad wiring', conversion inefficiencies blah blah blah to bump that guesstimated 84a up over 100, your compressor still goes from 'start' to 'run' in well under 10 seconds, so the bms SHOULD NOT disconnect. This is why i said "a battery that size should cover up a lot of wiring sins". There is a tiny tiny chance that one of the main leads inside the battery case has such a poor connection that it drops that much voltage under heavy current, but if that were the case repeated attempts to start the AC would quickly accumulate a noticeable amount of heat on whichever terminal led back to that poor connection(might even lead to smells and smoke), and since i believe these batteries are 'sealed' it would STILL be "the battery's fault".

Therefore my friends, what we are looking at 100% totally and completely falls on the battery not being able to do what it claims to be able to do. It can't do what it claims to be able to do continuously for an hour, FOR ONE SINGLE SECOND. ?

So why anyone is talking about the inverters.. is beyond me. Let's at least shit talk the right components.
 
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Vigo said:
Uhh... I kinda feel like people talking about the inverters are getting paid by a battery distributor to run interference.. WHAT?!

A ~12k btu/hr non-inverter AC probably does about 1300-1500w running. Figure 2-3x that for compressor start, with rapid decay. 3x 1500 is still within the surge rating of an (a single) HF 3kw inverter. Let's just say it is 4500w surge. 4500w / 53v shown on meter = 84a. Battery is rated by its manufacturer to do 100a continuously. As i said before, with a ~5kwh capacity it should not only be able to handle that startup surge, it should be able to handle that startup surge FOR AN HOUR STRAIGHT!

Lifepo4 battery voltage does not sag under load to any great extent, not even enough to trip low voltage disconnects unless your voltage was sitting right next to it to begin with. The only way the voltage reading and symptoms shown here happen is if the BMS disconnects the battery from the inverter. According to its own ratings, it SHOULD NOT disconnect under these circumstances because spec sheet says it will allow basically ANY current it is capable of, stated as ">250a", for at least one second. It should allow 150-250a discharges for 3 seconds, and 100-150a discharges for 10 seconds. Even if you talk about 'bad wiring', conversion inefficiencies blah blah blah to bump that guesstimated 84a up over 100, your compressor still goes from 'start' to 'run' in well under 10 seconds, so the bms SHOULD NOT disconnect. This is why i said "a battery that size should cover up a lot of wiring sins". There is a tiny tiny chance that one of the main leads inside the battery case has such a poor connection that it drops that much voltage under heavy current, but if that were the case repeated attempts to start the AC would quickly accumulate a noticeable amount of heat on whichever terminal led back to that poor connection(might even lead to smells and smoke), and since i believe these batteries are 'sealed' it would STILL be "the battery's fault".

Therefore my friends, what we are looking at 100% totally and completely falls on the battery not being able to do what it claims to be able to do. It can't do what it claims to be able to do continuously for an hour, FOR ONE SINGLE SECOND. ?

So why anyone is talking about the inverters.. is beyond me. Let's at least shit talk the right components.
Click to expand...
If I read it correctly. One battery and one inverter, couldn't start it.
Same battery and Two inverters, did.
That doesn't point to the battery.
 
One battery and one inverter should be able to start that ac consistently, but it doesn't.

One battery and TWO inverters should also be able to start the ac consistently, but it doesn't. It can start it 'sometimes'. We already mentioned that doubling the inverters doubles the capacitance in the conversion circuitry (might be a better term to describe that..) and doubles or significantly increases the total cross-sectional area of wire between the battery and inverters. Those are bandaids which should be unnecessary given the math in this situation. The math says one inverter should start the ac!

Even if you have no other information than 1 battery and 2 inverters, the odds of 2 inverters being broken is less than the odds of 1 battery being broken. But we have a lot more information than that!

What could cause the massive voltage drop between the battery and inverters, besides the battery? You're dropping 40v on those lines. We calculated roughly 80-100a during surge. That means that if the voltage drop was in the wires themselves, those wires would become ~4000w heaters during the startup surge (40v x 100a = 4000w, wiring and bad connections convert energy to heat = 4000w heater). It would be very difficult not to notice the effects of a 4000w heater during all the successive attempts to start that AC. That's why i said there's a tiny tiny chance of a wiring problem inside the battery, but unlikely because even if the problem was hidden inside the battery, you'd still notice the heat buildup of pulsing a 4000w heater inside a box the size of a briefcase. Even MORE likely to notice the effect of 4000w of heat generation, however brief, on wires you can easily touch. The only way to drop all those volts without obvious heat buildup, is if the BMS is disconnecting the battery.
 
My first guess was the battery wasn't big enough.
Compressor surge can be up to 5 x. I know that my 5k inverter and the same single battery wouldn't start my A/C, until I installed a soft start. In my case, it was the BMS tripping. But, when they were able to start it with two inverters. That made me think differently.
It's probably a combination of a few things. But without a second battery, it would be hard to confirm anything.
 
My first guess was the battery wasn't big enough.
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Well, i agree except I would like to be specific that the battery isn't acting big enough, when according to its specs it actually IS big enough. What is between the cells and the inverter that can make a big battery act small, is the bms. It doesn't hold up to its own spec sheet, not even close. Not saying every copy of it out there is bad, but this particular one almost certainly is! Or it's reacting to a cell problem. Either way it's internal to the battery.
 
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Vigo said:
Well, i agree except I would like to be specific that the battery isn't acting big enough, when according to its specs it actually IS big enough. What is between the cells and the inverter that can make a big battery act small, is the bms. It doesn't hold up to its own spec sheet, not even close. Not saying every copy of it out there is bad, but this particular one almost certainly is!
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I wish we could figure out what variable it is that causes some of these batteries to work fine and some to fail miserably.

I'm still curious what actual changes Signature made to the firmware update. I've asked but they haven't released any details.
 
Koldsimer said:
I wish we could figure out what variable it is that causes some of these batteries to work fine and some to fail miserably.

I'm still curious what actual changes Signature made to the firmware update. I've asked but they haven't released any details.
Click to expand...

Software updates must be announced in an official channel, and must be accompanied by official release notes, and preferably with a PKI put up by the manufacturer for verification that consumers are downloading the real thing, and not some hacked software.

Consumers shouldn't be chasing manufacturers about this!
 
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Vigo said:
Uhh... I kinda feel like people talking about the inverters are getting paid by a battery distributor to run interference.. WHAT?!
Click to expand...
Are you having trouble following the thread? Because that is not what is happening, in my opinion.

- Making sure the wiring is fully sufficient and not carrying more amps than it is rated for is a pretty reasonable thing. Some (cheap) 4AWG wire is only rated for 75A and the inverter manual only specifies 4AWG to carry 80A (with no consideration for surge or specification of a certain wire ampacity). A similarly sized inverter from a reputable manufacturer calls for 2AWG even with a 0 meter run.

- The inverter and wiring being criticized is from the SAME COMPANY as the battery distributor! Why would somebody run interference for them?! Any criticism of the inverter is definitely questioning the competence of the same battery distributors in this case.

- Other owners of Lifepower4 batteries show up and state their 13K BTU AC starts on a growatt 3000+single battery. Another reason to question why the EG4 inverter isn't handling things similarly, the EG4 is just another voltronic ripoff like MPP/growatt, not a major redesign (did I state that correctly? I don't buy hybrid garbage inverters).

- If the original poster had bought a growatt instead, would this thread even exist? Maybe if the AC is an especially difficult load (it isn't, OP claims it runs on a Honda 2000, if true a growatt 3000 can definitely start it).

- THIS THREAD is about being able to start the AC on one battery before the battery drops down to 20%, but only when he wired two inverters. Yeah. he actually started the AC with one battery. Did you read the thread before trying to claim there is a conspiracy? Even after he made a 2 inverter hack to get it working, we're still here criticizing how junk that one inverter is. A criticism that spreads to the battery maker since they are the same.

I use Lifepower4 batteries on two different 3000W inverters (Victron Multiplus II and Reliable WZRELB), and I'm able to run some decent motor starts without trouble, vacuums, deep fryers. I have personal experience with that battery. Telling somebody that you think they should probably replace their inverter, and continue trying to work with the same batteries is my honest opinion, not trying to run interference for anybody.

I'd also tell you to try and buy SOKs instead of EG4s if you had asked me, but you didn't.
 
timselectric said:
It's probably a combination of a few things. But without a second battery, it would be hard to confirm anything.
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If he hooks up a completely different, high quality inverter up, I think he would suddenly have different experiences, but that's only a hypothesis. If he lived next door I would let him use one of my Victron spares, he has shown himself technically capable, but that's unfortunately not an option.

My hypothesis is supported by the statement that the AC starts on an EU2000, which IMMEDIATELY overloads if hit by a 2000W surge. It's also supported by having seen 2000W pass through the Lifepower4 48 batteries that I own. Until it's tested with THAT battery, nobody knows though. It could be a bad cell weld! (No matter how rare)

That's the scenario I see for further testing with no additional batteries added.
 
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