• Have you tried out dark mode?! Scroll to the bottom of any page to find a sun or moon icon to turn dark mode on or off!

diy solar

diy solar

Fuse size and type between Inverter and Battery

Rebuild1850

New Member
Joined
Nov 5, 2024
Messages
4
Location
Rich Square NC
Given:
I have a this inverter:

4000 Watt Pure Sine Wave Power Inverter for Vehicles Car RV,DC 12v to AC 110v 120v Inversor with LCD Display,4AC Power Outlets and 1 Type C, 2USB Charging Port and Remote Control(JUIBAESS)​

link: https://www.amazon.com/Pure-Sine-Wave-Inverter-JUIBAESS/dp/B0C5T6WYGB

I have this battery:

WEIZE AGM Group Size 4D Battery, 12 Volt 200Ah Deep Cycle Battery​

Link: https://www.amazon.com/WEIZE-Battery-Perfect-Trailers-Motor-Homes/dp/B0CGQZ4CS1

i also have six 200w panels:

JJN Bifacial 400 Watt Solar Panel 12V 10BB Monocrystalline Solar Panels High Efficiency Solar Module​

In three pair series with 8GA wires then into Combo Box
Link: https://www.amazon.com/dp/B0C1Z3F8Y..._1_4&amp=&crid=RNYHGSVOJFIR&sprefix=jjn+&th=1

Combiner Box:
I also have an eco worthy combiner box

6 String PV Combiner Box with 6*10A Circuit Breakers for Solar Panel System​




Action:
For the 4gage wire: I am looking at ANL fuses and but prefer the Class T fuse
Please help me size the fuse.
Also I was giver 4 gauge? wires by invertor manufacter JUIBAESS
 
Please help me size the fuse
Difficult giving advice here.

With a 12v system a 4000 watt inverter running at full power will take in excess of 350 amps with lead batteries. This is not practical with a single 200 Ah AGM battery, running off the battery alone.

The solar, no solar controller is identified.
Six 200 watt panels with a MPPT controller will develop , in theory , a maximum 100 amps into a 12v system. In practice the current will be lower say 70 to 80 amps. This is too high for a single 200 Ah AGM battery.

Summary.
4000 watts of inverter is not practical in a 12v system, the currents are high and not easy to engineer successfully. Identify actual AC loads and use a lower power inverter if possible. If 4000 watts is a requirement consider a 24 or 48 volt system.
A 200 Ah AGM battery cannot be excessively charged or discharged continually at high currents without early death. Suggest a 40 to 50 amp charge rate and a 100 amp discharge rate as a maximum. Need more AGM batteries or consider lithium battery.
A 100 amp output solar controller is expensive, a 24 volt system would need a 50 amp controller and a 48 volt system a 25 watt controller.
 
Thank you very much Mike.
I will add an identical Weise battery to bring it up to 24 volts. (hook up SERIES I assume to get to 24v)

My controller is MPPT 12v/24 rated 60 amp. I forgot to add this in my givens.
maxPV 50V
Maxpv 780/12v or 1560w/24v

My 6 panels @200w each is under the 1560 limit.

Am I correct to assume that controller would be fine if I add another Weise 24 volt battery

EcoWorthy did the calcs and said to expect >45 v and 30 amps out of their box.
They also said that for each string added (in pairs of 2 panels would add 10 amps I believe.

Also:
Please comment on the fuse from battery to inverter.

Since you are the battery expert, Is it advisable to remain ith Weise for the additional or can I mix brands?
What battery manufacture would you suggest.

Thank you very much.
This is my firsst post and I hope that it is in the right topic category?
 
I will add an identical Weise battery to bring it up to 24 volts. (hook up SERIES I assume to get to 24v)

Your solar charge controllers may be OK, but your inverter probably won't be. If it's a fixed voltage inverter (most are) then it's only going to operate on a 12 volt system.

Connect the second battery in parallel and you'll be OK.

While you have a 4000 watt inverter, how many watts will you actually pull on the AC circuit. The answer to this will help clarify how to size the wire and the fuse(s).

As I recall, Will Prowse took a Weize LiFePO4 battery apart and didn't have any major objections. Before connecting the second battery, make sure both are at the same state of charge.

Your thread is OK where it is since you have questions that span multiple area.
 
A 4000 watt inverter, powered by 12 volt needs ~ ( 4000 watts ) / ( 12 volt ) ~ 400 amps.

I cannot think of any 8D AGM batteries made that can discharge 400 amps and hold 12 volts, so maybe just plan around a 100 amp setup.

As a "starting point" here is an ampacity chart for various wire sizes. Look down the left most column of current until you reach the desired current.


Each 4 awg wire is good for maybe 70 amps.
 
a Weize LiFePO4 battery apart
The battery being used is AGM.
I suggest a reset on the design.
I assume you have a 12v 4000 watt inverter, one 200Ah AGM battery, 1200 watts of panels and a 60 amp MPPT controller.
Unless you obtain a 24 volt inverter you can only use a 12v system.
Running a 12v 4000 watt inverter at full power , even with two 200 Ah AGM in parallel, is hard on the batteries, expect, at 4000 watts, a run time of 35 minutes, and a short battery life.

What would be useful, is to know the expected AC power, if the inverter is being run at a lower power, then a 12v system with AGM batteries becomes more practical.
 
Go for a MRBF fuses.
Its go up to max 350a and 48volts .
Its close to your battery connection.
Marine grade (ABYC standard)
 
The battery being used is AGM.
I suggest a reset on the design.
I assume you have a 12v 4000 watt inverter, one 200Ah AGM battery, 1200 watts of panels and a 60 amp MPPT controller.
Unless you obtain a 24 volt inverter you can only use a 12v system.
Running a 12v 4000 watt inverter at full power , even with two 200 Ah AGM in parallel, is hard on the batteries, expect, at 4000 watts, a run time of 35 minutes, and a short battery life.

What would be useful, is to know the expected AC power, if the inverter is being run at a lower power, then a 12v system with AGM batteries becomes more practical.

The battery being used is AGM.
I suggest a reset on the design.
I assume you have a 12v 4000 watt inverter, one 200Ah AGM battery, 1200 watts of panels and a 60 amp MPPT controller.
Unless you obtain a 24 volt inverter you can only use a 12v system.
Running a 12v 4000 watt inverter at full power , even with two 200 Ah AGM in parallel, is hard on the batteries, expect, at 4000 watts, a run time of 35 minutes, and a short battery life.

What would be useful, is to know the expected AC power, if the inverter is being run at a lower power, then a 12v system with AGM batteries becomes more practical.


I am rebuilding an old 1850 dated house in NC. My needs are really like a work job site with security. (no electric tools), all portatable for recharge only occasionally.

Note:
My inverter manual says ts 9.5v-16v DC rated power 12v and 19v-32v dc for rated power 24v

I will need the follwoing ac power:

Right now I am looking to run an electrical heater (1500 w each ) only on cold days.
A computer that keeps my 8 Blink devices available remotely. ?watts
A Calix GigaSpire Blast GS4227W modem that has a maximum power of 36 watts. It also has an output current of 3 amps and an output voltage of 12 volts (DC). I will run this full time for internet and my Blink security access.

Kobolt tool charger 45w only when needed

My George Foreman grill at 760w once a day for a about 10 minutes only when needed

Of course my Apple MacBook Pro charger when I am only site ?watts. only when needed
Perhaps a Raspberry Linux or desktop device full time. ?watts Full Time

A RV mini heater for showers rated ar 3000w say, every two days for about 20 minutes. only when needed

A light in one room say 40w only when needed


Thats it.
Do you think my Inverter will be ok with such a small load?
It's just to get my by until I can afford more panels, more batteries to get the entire house wired in due course.?

Again, Do you have fuse suggestions to the battery to inverter?
 
The battery being used is AGM.
I suggest a reset on the design.
I assume you have a 12v 4000 watt inverter, one 200Ah AGM battery, 1200 watts of panels and a 60 amp MPPT controller.
Unless you obtain a 24 volt inverter you can only use a 12v system.
Running a 12v 4000 watt inverter at full power , even with two 200 Ah AGM in parallel, is hard on the batteries, expect, at 4000 watts, a run time of 35 minutes, and a short battery life.

What would be useful, is to know the expected AC power, if the inverter is being run at a lower power, then a 12v system with AGM batteries becomes more practical.
Right now I am looking to run an electrical heater (1600w?)
Also a laptop intermittent.
A computer that keeps my 8 Blink devices available remotely. That means only a modem
Go for a MRBF fuses.
Its go up to max 350a and 48volts .
Its close to your battery connection.
Marine grade (ABYC standard)
I like that type of connection. Its quick and easy. its the idea of dumping sand on a arc with the Class T that caught my eye
 
A computer that keeps my 8 Blink devices available remotely. ?watts

As I recall, you can put ten cameras on a sync module. So you need just one sync module as long as all 8 cameras are in range. The sync module is pretty low consumption. It connects via USB which is 5v and I think it's rated at 1 amp. So 5 watt hours. Seems kind of low to me, but I never measured what it actually draws.

Again, Do you have fuse suggestions to the battery to inverter?

Worst case you need a 500 amp fuse. Best case, it all depends on your largest combined simultaneous loads. It sounds like that would be no more than 2000 watts. 2000 watts / 12 volts / .85 (inverter efficiency) * 1.25 (to prevent nuisance trips) = 245 amps. Call it 250 amps. We don't know the actual inverter efficiency, so we use .85 as a catch-all.
 
Resistive heaters are murder on battery capacity. With 12v agm you are looking at under an hour runtime.

12v200ah = 2400whr but for agm use 50% = 1200whrs
1500w heater uses 1500Whr in an hour...

Running any sort of electric heat will require a much bigger battery.
 

diy solar

diy solar
Back
Top