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Bad inverter?

R

RStephen

New Member
Joined
Aug 23, 2022
Messages
7
Just got a new Reliable 300 watt 6000 watt peak inverter and testing not going well!
13.1 on lifepo04 battery and testing with1500 watts heater and inverter shuts down in alarm state. I have also tried another load (heat gun) with similar requirements and same result.
Is this junk or are the two outlets not capable of this load and need a direct outlet wired to inverter. No documentation on outlet load.

inverter here... https://www.amazon.com/dp/B07XRP1GTF?ref=ppx_yo2ov_dt_b_product_details&th=1



 
Reliables are cheap inverters. I've owned 3 of them but they all worked. 2 of them I blew up (my fault). The 3rd I have in a DIY solar generator and it still works but it's only had light use.

1500w / 12v = 125a + a bit more for efficiency loss. 125-150a pull on a single battery is pretty hefty. Is it possible you're pulling down the voltage on the battery so low it's going into low battery voltage alarm? In other words, it could be battery amp overload rather than a bad inverter.
 
RStephen said:
Just got a new Reliable 300 watt 6000 watt peak inverter and testing not going well!
13.1 on lifepo04 battery and testing with1500 watts heater and inverter shuts down in alarm state. I have also tried another load (heat gun) with similar requirements and same result.
Is this junk or are the two outlets not capable of this load and need a direct outlet wired to inverter. No documentation on outlet load.

inverter here... https://www.amazon.com/dp/B07XRP1GTF?ref=ppx_yo2ov_dt_b_product_details&th=1



Click to expand...
Do not use the supplied cables from inverter to battery. They are undersized; plus what is the distance from battery to the inverter? for 150A pull, you need big wire (probably one "0" distance within 1-2 feet). Try bigger cable, you may eliminate that issue. Plus fuse in between inverter and battery.
 
RStephen said:
Just got a new Reliable 300 watt 6000 watt peak inverter and testing not going well!
13.1 on lifepo04 battery and testing with1500 watts heater and inverter shuts down in alarm state. I have also tried another load (heat gun) with similar requirements and same result.
Is this junk or are the two outlets not capable of this load and need a direct outlet wired to inverter. No documentation on outlet load.

inverter here... https://www.amazon.com/dp/B07XRP1GTF?ref=ppx_yo2ov_dt_b_product_details&th=1



Click to expand...
What is the rating of the batteries?
Can we see your wiring?
Are you using good circuit breaker/fuse?
Is the batteries fully charged?
13.10V measured on the batteries without load?
May be the batteries cannot supply enough power or bad connection/wiring with large Vdrops.
 
OffGridInTheCity said:
Reliables are cheap inverters. I've owned 3 of them but they all worked. 2 of them I blew up (my fault). The 3rd I have in a DIY solar generator and it still works but it's only had light use.

1500w / 12v = 125a + a bit more for efficiency loss. 125-150a pull on a single battery is pretty hefty. Is it possible you're pulling down the voltage on the battery so low it's going into low battery voltage alarm? In other words, it could be battery amp overload rather than a
Click to expand...

NOLA_Castle said:
Do not use the supplied cables from inverter to battery. They are undersized; plus what is the distance from battery to the inverter? for 150A pull, you need big wire (probably one "0" distance within 1-2 feet). Try bigger cable, you may eliminate that issue. Plus fuse in between inverter and battery.
Click to expand...
OK... mistake #1, I was using cables that came with inverter. The inverter to battery distance is 2 ft. Fuse and holder on order. Currently on bench for testing until I feel comfortable with everything. Fire extinguished within 6 ft. :cool:
 
RStephen said:
OK... mistake #1, I was using cables that came with inverter. The inverter to battery distance is 2 ft. Fuse and holder on order. Currently on bench for testing until I feel comfortable with everything. Fire extinguished within 6 ft. :cool:
Click to expand...
If your battery BMS limit is 100A, then your inverter won't make it. Battery capacity is also a factor. Cheap / bad fuse will also contribute to the cause, just like Bud Martin indicated.
 
So... Am getting some welding cables to use for battery hookup. Fuse and holder on order.

Bud Martin said:
What is the rating of the batteries?
Can we see your wiring?
Are you using good circuit breaker/fuse?
Is the batteries fully charged?
13.10V measured on the batteries without load?
May be the batteries cannot supply enough power or bad connection/wiring with large Vdrops.
Click to expand...

Battery spec link listed here...
https://www.amazon.com/dp/B0B6JH4STQ?ref=ppx_yo2ov_dt_b_product_details&th=1

Panel specs here.

solar test bench.jpg
 
OffGridInTheCity said:
...1500w / 12v = 125a + a bit more for efficiency loss. 125-150a pull on a single battery is pretty hefty. Is it possible you're pulling down the voltage on the battery so low it's going into low battery voltage alarm? In other words, it could be battery amp overload rather than a bad inverter.
Click to expand...
This is all you need to know. You are trying to pull 125% of the battery output. Different cables wont help you. A second battery in parallel could give you 200 amps continuous (questionably).

I would add that at 13.1 resting volts you are working with a battery with only a 40% charge and the voltage sag isn't working in your favor.
 
Last edited:
RStephen said:
ttery specs here...
The last time I tested, I noticed an audible click coming from battery and it's voltage dropped to zero so it looks like the battery low voltage trigger interrupted the battery output.
Click to expand...
Your battery BMS is 100A. Your load surge is at least 125A (via inverter). No wonder, your inverter is shutting down. You need bigger 12V battery with 200Ahr and BMS 200A to get to your 125A load. Concurred with HighDesertOffgrid.
 
Try with 1000W peak load or less, see if your inverter is shutting down. Make sure, your battery is fully charged.
 
NOLA_Castle said:
Your battery BMS is 100A. Your load surge is at least 125A (via inverter). No wonder, your inverter is shutting down. You need bigger 12V battery with 200Ahr and BMS 200A to get to your 125A load. Concurred with HighDesertOffgrid.
Click to expand...
Ok… I’m a little confused about the above math. The heater is rated at 1500 watts but at 120vac which comes out to 12.5 amps. How can 12.5 amps be too much of a load for a battery rated at 100ah?
 
RStephen said:
Ok… I’m a little confused about the above math. The heater is rated at 1500 watts but at 120vac which comes out to 12.5 amps. How can 12.5 amps be too much of a load for a battery rated at 100ah?
Click to expand...
Your battery is 12V right? as source, not 120V. To power up your 1500Watt load with 12V battery, then 1500/12=125A.
 
RStephen said:
Ok… I’m a little confused about the above math. The heater is rated at 1500 watts but at 120vac which comes out to 12.5 amps. How can 12.5 amps be too much of a load for a battery rated at 100ah?
Click to expand...
The BMS current is rated at the battery voltage, not the output voltage of the inverter.
NOLA_Castle said:
Your battery is 12V right? as source, not 120V. To power up your 1500Watt load with 12V battery, then 1500/12=125A.
Click to expand...
This
 
NOLA_Castle said:
Your battery is 12V right? as source, not 120V. To power up your 1500Watt load with 12V battery, then 1500/12=125A.
Click to expand...
BMS is battery mgmt system, which has its own limit, such as 100A, 200A, etc. Even your battery is 12V and 200Ah, the BMS can be 100A, meaning the load is limited by battery 100A BMS. You need to find 12V battery, 200Ah with 200A BMS in order to support 125A load. It is important to understand the battery specification or do power audit prior to purchasing equipment.
 
HighDesertOffgrid said:
The BMS current is rated at the battery voltage, not the output voltage of the inverter.
Click to expand...
NOLA_Castle said:
BMS is battery mgmt system, which has its own limit, such as 100A, 200A, etc. Even your battery is 12V and 200Ah, the BMS can be 100A, meaning the load is limited by battery 100A BMS. You need to find 12V battery, 200Ah with 200A BMS in order to support 125A load. It is important to understand the battery specification or do power audit prior to purchasing equipment.
Click to expand...
Ok, lets see if this is correct… if i check current draw on dc input i should see 125a but on ac output side i will see 12.5a? To correct this, can i add another same battery?
 
Yes.
RStephen said:
Ok, lets see if this is correct… if i check current draw on dc input i should see 125a but on ac output side i will see 12.5a? To correct this, can i add another same battery?
Click to expand...

Yes. Watts are always going to be your constant. Use them as your basis for all of your calculations.

To achieve the capacity of the 3000w inverter, you will need 3000/12v= constant battery amps needed.
 
Your battery is only 100Ah ,too small for the 1500W load,please add battery to 200Ah or 300Ah and full charge them to 13.5V, then try again
 
You also need to factor in inverter efficiency, 85% is typical.
So for worst case when the battery is close to low Voltage shutdown, around 10V, that means the power draw from the battery will be 1500W/0.85 = 1765W, 1765W/10V = 176.4A (147A @12V) current draw from the battery.
 
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