[Kenny]

After seventy-some years, I got bored and converted to a camper.
No previous experience including electrical, carpentry but I made.

Two 12V 100W solar panels parallel connected.
Two 12V 100Ah AGM parallel connected.

Even on 800W use, the Inverter cut off after a few minutes.
Try to connect Isolator to complement while using a hot plate.

Wanderer has no connect point.
Recently found the cable is not big enough, some say need 2G or 1G.

Any advice is appreciated.

(2022-05-07) Thanks everybody.
After advise, changed 4G wire to 2G with 125A fuse.
Also main fuse box 10G wire have 20A fuse.
Still not enough to operate 1200W induction cook top.
Will check all voltage level. And put the result next week. (out of town)

 

[Uvan]

How old is your battery? I found from my previous setup using two old batteries(connected as parallel), one of the batteries was bad and my voltage drop fast and inverter so working due to low voltage.

Also what kind of fuse are you using? Some people are experiencing voltage drop with cheap resettable fuse.
I'm assuming your ground is the same size gauge as the the corresponding wire.
If you have multimeter, you should check the voltage at different part of the system and see if you have any major voltage drop.

 

[SteveSS]

Yep, voltage drop somewhere. I had a similar problem caused by degraded AGMs. They go bad if you don't/can't fully charge them often. In addition to the previous suggestions, 4G wires feeding your 1500W inverter seem too small. Check your inverter's manual for recommendations. My 2000W calls for 2-0G. All your negative wires should be the same size as their associated positive wires.

Your (?) isolator wire gets connected to your coach batteries, same as your inverter, solar, and DC fuse block. Folks often use intermediate + and - busbars to accommodate all those connections. Lastly, the isolator won't help the situation unless the engine is running.

 

[HarryN]

Which inverter and battery brand / model?

Perhaps watch your battery voltage while the inverter load is turned on and see how quickly it drops below the inverter low voltage point.

 

[Kenny]

Thanks, everybody. Changed power diagram. I will reply after one week (out of town)

 

[Kenny]

Pre-check Test result
1. Using only an 800W induction level, it stops about 2 minutes after the start.
Start 13.7V, and voltage falling fast to triggered fuse at 11.9V
The 1500W inverter makes AC 119V.
After disconnecting the inverter, the battery voltage back to 13.5V in a minute.
2. Test with various AC tools under 400W, all work fine.
3. Disconnect all the lines and check the battery voltage.
13.4V and 13.5V changed after 30 minutes to 13.3V, 12.7 each.
So the battery looks good to retain its power (Renogy 100Ah AGM x 2)
and the connection is good before and after.

1500W Pure sine inverter PS1005

I guess battery power is not enough, and try adding DC-DC charger 40A
and Rover 30A controller (It was Wanderer 30A PWM)

Add a diagram and if you find wrong, please let me know to correct it.

 

[Uvan]

How is the inverter connected to the battery?
Also how old is your battery?
Are you using ANL fuse on the inverter?
I'm running two 6v 215ah connecting in series so it's about the same ah as yours. I use my instant pot all the time which draw 750w all the time and no issue. We also use the induction stove a few times in under 1000w setting and no issue. So either a internal resistance some where it(cable connection point, fuse, etc), bad battery or possible bad inverter??

Maybe try charging each battery individually first so they get good charge, sometime when connecting in parallel, the weaker battery will trick the charger to think its full.

 

[GaryBIS]

Hi,
The inverter dropping out at 11.9 volts seems kind of high.
According to its manual, it should not drop out until 10 volts.

Can you measure the voltage right at the inverter terminals to make sure there is not a lot of voltage drop from the battery to the inverter?

Similar to what Uvan reports, I have essentially the same 1500 watt inverter as yours from GoWise and have run a small microwave with an actual consumption of 996 watts run from 2 flooded lead acid golf cart batteries with the batteries at 80% state of charge. The voltage drops down to 11.2 volts, but it hangs in there. I have run this combination for as long as 10 minutes with no cutout. Your two AGMs should do better than my FLAs as long as they are in descent shape.

Gary

 

[SteveSS]

I agree, 2x100Ah should run an 800W appliance with no problem, as long as your batteries are charged and in good shape. The one battery dropping from 13.5V to 12.7V in 30min is a little suspicious. You might have one bad battery. You could have them both tested at a battery dealer, Interstate or the equivalent.

You want to start any testing with two fully-charged batteries. The best way to do that is one at a time, with a automotive battery charger on the AGM setting. Have yours ever been fully charged? AGMs need that on a regular basis to stay healthy.

Replacing your solar charger and isolator won't help with voltage drop. At best, it would only charge your batteries a little faster, maybe. Find out what's causing the voltage drop. If it's not bad batteries, it could be a loose connection somewhere. I've experienced both.

 

[Kenny]

Thanks for everybody's advice. Here is my final circuit diagram.
As you already knew, I have very little basic knowledge about electricity.
Some parts of the drawing are not done yet, waiting for parts to come.
Before I tear down the previous connection, I make sure how to set it correctly.

For battery check, I will disconnect one full day and then find how much voltage drops.

 

[Kenny]

Disconnect two AGM batteries and left more than 30 hours.
Start voltage both 13.6V, after 12.84V, 12.82V respectively.
So up to now, the thing I will change is the wire to inverter 4G (it came with the machine) to 2G
and size down the fuse to 150A.
Inverter produces AC 119V on both ends. Connections seem all tight.
Batteries look good enough and constantly top off from a solar charger.

I'm still not sure why it triggered trip fuse at 11.9V.
After I change to 2G wire, then I'll ask for advice again.

 

[HarryN]

Disconnect two AGM batteries and left more than 30 hours.
Start voltage both 13.6V, after 12.84V, 12.82V respectively.
So up to now, the thing I will change is the wire to inverter 4G (it came with the machine) to 2G
and size down the fuse to 150A.
Inverter produces AC 119V on both ends. Connections seem all tight.
Batteries look good enough and constantly top off from a solar charger.

I'm still not sure why it triggered trip fuse at 11.9V.
After I change to 2G wire, then I'll ask for advice again.

Wire sizes are listed such as

4 awg
2 awg
0 awg (also called 1/0)
00 awg (also called 2/0)
0000 awg (also called 4/0)

What you need is 00 or also called 2/0, not 2 awg. You could also use 0000 also know as 4/0.

With an entry level battery like a renogy, it will take 4 of them to keep up with that kind of load.

__

 

[HarryN]

On the solar charge controller, the rover is actually not as good for this application as the wanderer.

If possible, swap it out for a bogart SC 2030.

__

From the batteries to the blue sea fuse block - consider to swap in 6 awg wire instead of 10 awg.

Also - try to not buy anything else from Renogy. To make a 12 volt system run a heavy inductive load, pretty much everything has to be perfect.

 

[Kenny]

Wire sizes are listed such as

4 awg
2 awg
0 awg (also called 1/0)
00 awg (also called 2/0)
0000 awg (also called 4/0)

What you need is 00 or also called 2/0, not 2 awg. You could also use 0000 also know as 4/0.

With an entry level battery like a renogy, it will take 4 of them to keep up with that kind of load.

__

Thank you for the wire size.
For the battery, I will keep the two 100Ah AGM but run the engine with a DC-DC charger to back up the power level for short time, less than 10 minutes, while using an induction hot top. Will it be accomplished with this setup?
I'm still waiting for the DC-DC charger and other parts to come.

 

[HarryN]

Thank you for the wire size.
For the battery, I will keep the two 100Ah AGM but run the engine with a DC-DC charger to back up the power level for short time, less than 10 minutes, while using an induction hot top. Will it be accomplished with this setup?
I'm still waiting for the DC-DC charger and other parts to come.

I don't know if it will work or not. Your project is right on the edge where it is hard to tell from an armchair.

A 1200 watt resistive load (example toaster) is very easy for an inverter to run.

A 1200 watt inductive load (like a motor or inductive cook top) is very challenging for an inverter to run.

In the end, electricity in a van is somewhat of an experiment. You can either do the experiment yourself and enjoy the learning process of failure / success with various equipment, or hire someone who has already paid the price for the failure / success with various equipment and let them have the "joy" .

This is why most marine electricians or van electrical system builders don't like to change away from what they know will work vs the latest marketing hype on instagram or youtube.

I have turned down all but 2 projects where the customer purchased renogy parts.

In the last one, I used only their solar charge controller because they owned it and had paid quite a bit for it, but what I should have done is thrown it away and just used what I knew would work. Would have been much cheaper for me and a lot less stress.

 

[Lolaeliz]

I don't know if it will work or not. Your project is right on the edge where it is hard to tell from an armchair.

A 1200 watt resistive load (example toaster) is very easy for an inverter to run.

A 1200 watt inductive load (like a motor or inductive cook top) is very challenging for an inverter to run.

In the end, electricity in a van is somewhat of an experiment. You can either do the experiment yourself and enjoy the learning process of failure / success with various equipment, or hire someone who has already paid the price for the failure / success with various equipment and let them have the "joy" .

This is why most marine electricians or van electrical system builders don't like to change away from what they know will work vs the latest marketing hype on instagram or youtube.

I have turned down all but 2 projects where the customer purchased renogy parts.

In the last one, I used only their solar charge controller because they owned it and had paid quite a bit for it, but what I should have done is thrown it away and just used what I knew would work. Would have been much cheaper for me and a lot less stress.

Kenny bought my40a renogy DC2DC and 30a rover MPPT for $110. I sold them because I replaced them with a renogy DC-DC/MPPT combo unit. He got 2 really good barely used products for 1/3 of the market value. You may hate Renogy products, but these were nearly brand new --installed, but used for only one trip. Renogy may not be the best in some peoples eyes, or what you recommend, but they are competent products the I use and have been very satisfied with. I know you mean no harm, but implying to a newbe that they just purchased inferior products can really twist the newbe mind.

 

[HarryN]

Kenny bought my40a renogy DC2DC and 30a rover MPPT for $110. I sold them because I replaced them with a renogy DC-DC/MPPT combo unit. He got 2 really good barely used products for 1/3 of the market value. You may hate Renogy products, but these were nearly brand new --installed, but used for only one trip. Renogy may not be the best in some peoples eyes, or what you recommend, but they are competent products the I use and have been very satisfied with. I know you mean no harm, but implying to a newbe that they just purchased inferior products can really twist the newbe mind.

Hi - I am not implying anything. I am completely comfortable telling my honest experiences and trying to help people avoid purchasing their products. For many years my own parents suffered from the mistakes of buying products that seemed like they should work - but were junk and I am fully committed to helping others try to avoid the same fate.

 

[Lolaeliz]

Hi - I am not implying anything. I am completely comfortable telling my honest experiences and trying to help people avoid purchasing their products. For many years my own parents suffered from the mistakes of buying products that seemed like they should work - but were junk and I am fully committed to helping others try to avoid the same fate.

But you are stating as if an absolute fact, when it is your opinion. Will Prowse gave the combo unit a great review, after testing the product under various situations. And the Renogy DC2DC also has great reviews. A blanket statement that all renogy is crap is grossly generalized, and your personal opinion.

EDITED TO ADD: When one is designing on a budget, there are many factors to consider when chosing components, where blanket "it's all crap" statements lack finesse.

 

[HarryN]

But you are stating as if an absolute fact, when it is your opinion. Will Prowse gave the combo unit a great review, after testing the product under various situations. And the Renogy DC2DC also has great reviews. A blanket statement that all renogy is crap is grossly generalized, and your personal opinion.

EDITED TO ADD: When one is designing on a budget, there are many factors to consider when chosing components, where blanket "it's all crap" statements lack finesse.

The OP asked me personally - "if the setup would be capable of powering a 1200 watt inductive cooktop."

What I said was that it is very challenging to power a 1200 watt inductive load, vs powering a 1200 watt resistive load is much easier. In other words - if you are on a budget - buy an electric skillet (resistive load) instead of an expensive to run inductive cook top.

I also said - I don't know because it is a very marginal configuration and the only way to know is to try it out.

There is literally no data sheet with useful information regarding what renogy AGM batteries can do, but I have tested a number of batteries and even hired a consultant who tested batteries for the US govt to advise me in the past, so I do have some sense of what a battery pack can support under heavy load conditions and how it varies from brand to brand.

What I know is that if people stick to the 500 - 600 inverter watts / good quality battery, they will succeed, and I reiterated this.

I didn't say anything about the BTB charger at all, other than my general experience looking at the bulk of their products being - very marginal for the purpose.

I do have direct experience with Renogy solar charge controllers as well as 5 or 6 other brands, and PWM vs MPPT. It is a common error to try to use an MPPT solar charge controller with an 18 volt panel in a 12 volt system. If he wires the panels in series, then it can work, but it will still have a lot of standby power draw. The built in Renogy settings are wrong for charging a LiFe battery and the SOC monitor system is very poor compared to other brands on the market.

Will is well known for trying to run heavy loads on a battery pack that will not support sufficient voltage to run anything else (and have such low voltage sag that 12 volt refrigerators and heaters would turn off. This is an area that I disagree with his assessment.

I will try to go back to not being quite so openly critical of their products - although you yourself have posted great frustration with them.

 

[FormInFunction]

I generally like Will Prowse's reviews (except for his very YT-fake enthusiasm for the every simple thing) but he gets paid/sponsored for many of his reviews. Knowing that, he's basically just a marketing arm due to his broad audience...take that for what it's worth I guess.