Should I ditch the Sargent? Please help

[The Flying Scotsman]

I’m wanting to upgrade my power set up in my camper.
I’m wanting to be able to run for at least a week off grid.
Off grid I would run my fridge, and tv for a couple hours at night. The water pump occasionally and the diesel heater very occasionally.
I’m in the process of buying a 2000w inverter. It was formerly dellmassive’s I believe.
I’m currently running a Sargent box and leisure battery on a split charge relay with a solar panel on the roof. See pics
Advice I’ve had so far is to junk the Sargent upgrade the solar panel on my roof and swap leisure battery for a lithium.
I’m really handy at doing everything myself but am clueless as to what I need and how to connect it up.
Any advice is appreciated cheers

 

[Deaky]

Off grid for a week with a 2000w inverter. What are you gonna be using that for?

 

[The Flying Scotsman]

Off grid for a week with a 2000w inverter. What are you gonna be using that for?

I thought that was what I was needing? what do you suggest?
As I mentioned I’m pretty clueless about the electric side of things

 

[roadtripper]

Talked about a similar replacement/extension here recently:

Upgrade from Sargent EC155 Advice Request

Hi all I've been running the Sargent EC155 for the last 5 years or so and it's done the job. I've just upgraded to a Lithium Fogstar battery from my lead acid LB and the Sargent now keeps alarming randomly for high voltage. I've not changed anything else and have read that the Sargent's don't...

www.t6forum.com

As @Deaky says if you are adding a 2000w inverter that will dominate your power use and dictate what system you fit, so you need to be clear what you expect.

 

[roadtripper]

I thought that was what I was needing? what do you suggest?
As I mentioned I’m pretty clueless about the electric side of things

Nothing you've listed needs mains power, so there is no need for an inverter?

Assuming you choose a camping TV that runs off 12v...

 

[Drive Wayne]

Surely you'll be needing a toaster? An induction hob a coffee machine? A kettle? You'll be able to with a 2000 watt inverter and 200Ah lithium battery, the 240 volt world would be your, in your case, 'salmon'!

 

[The Flying Scotsman]

Nothing you've listed needs mains power, so there is no need for an inverter?

Assuming you choose a camping TV that runs off 12v...

My tv works on both 12v and 240 on EHU.
So the inverter would only give me power to plug external things into?
Which would still be really handy. So would still be nice to have and install when I’m upgrading everything else. I could take my ps5 away
So what are the main components that I need for lots more power to run off grid ?
Mainly the lithium battery?
What about my solar set up ?
What would you recommend for a good system?
Thanks for your help

 

[The Flying Scotsman]

Surely you'll be needing a toaster? An induction hob a coffee machine? A kettle? You'll be able to with a 2000 watt inverter and 200Ah lithium battery, the 240 volt world would be your, in your case, 'salmon'!

The toaster would be really handy too.
I got a wee one for in EHU.
It’s blue
Couldn’t find purple

 

[The Flying Scotsman]

Talked about a similar replacement/extension here recently:

Upgrade from Sargent EC155 Advice Request

Hi all I've been running the Sargent EC155 for the last 5 years or so and it's done the job. I've just upgraded to a Lithium Fogstar battery from my lead acid LB and the Sargent now keeps alarming randomly for high voltage. I've not changed anything else and have read that the Sargent's don't...

www.t6forum.com

As @Deaky says if you are adding a 2000w inverter that will dominate your power use and dictate what system you fit, so you need to be clear what you expect.

Never seen this post will check it out thanks

 

[roadtripper]

If you put an inverter on the system you will need a much physically bigger and much more expensive system to use it.

A 2000w inverter will require at least a pair of good brand LiFePo batteries and you will need to be able to replace that charge so you will need a similar high end investment in EHU, DC-DC chargers, as many solar panels as you can fit and associated MPPT chargers.

Running any mains device uses enormous amounts of power. It's not something to do speculatively.

 

[roadtripper]

Also, unless it's not visible due to the lighting, the cabling around your battery in this photo is a lot thinner guage than I would expect, and the use of a battery terminal as a ground bolt is... unusual

With the inverter you are proposing you are talking about 170A flowing under load. Your cabling is going to need a significant upgrade.

As an aside is anything holding your current battery down, it wouldn't take much of a jolt to lift it over those furniture brackets and then you are in a world of trouble.

 

[The Flying Scotsman]

Also, unless it's not visible due to the lighting, the cabling around your battery in this photo is a lot thinner guage than I would expect, and the use of a battery terminal as a ground bolt is... unusual

With the inverter you are proposing you are talking about 170A flowing under load. Your cabling is going to need a significant upgrade.

As an aside is anything holding your current battery down, it wouldn't take much of a jolt to lift it over those furniture brackets and then you are in a world of trouble.

Thanks for all that.
I was surprised at the cable thickness also.
I’ve got a fair bit good power wire from when I installed big power audio installations with several ampliers. So will look at upgrading the cables myself.
So by the sounds of it a 2000w inverter will take major upgrades to get working? Not really worth it for the occasional use it will get.
I’m much more interested in the rest of my 12v system being able to last much longer.
I’m prepared to upgrade the battery the management system and even the solar panel for this. I will also fit heavier gauge cables.
What battery would you recommend?
I read that thread and TBH some of it went over my head but picked up I will need a CTEK.
I would appreciate you recommending a battery/CTEK/solar system that would last for a while off grid.
Also would a much smaller inverter be a good plan to incorporate? Or will it cause to much hassles?
Thanks.

 

[CAB]

1. Biggest Lithium you can afford;
2. Decent B2B charger to replace the split relay;
3. MPPT solar controller to replace the Epever controller.

Don't see why you need to replace the Sargent; yes it isn't perfect for mains charging the lithium but doesn't it also provide the 12v distribution and fuses?

With solar in summer and B2B the rest of the time, as long as the lithium is big enough you should be OK for days as long as you can heat / boil stuff with gas.

NB. I have little idea of actual products, this is just distilling other advice I have seen. My own van has a caravan charger and solar would be useless 1/2 the time!

Edit:
If you have the lithium capable of running it, then no reason not to get the inverter. They can handle much higher currents for longer duration than lead-acid.

 

[roadtripper]

I recommended a CTEK in that thread as the original install had already been fitted with a CTEK to better charge the AGM battery it was just an old model that didn't have lithium capabilities. So a straight swap made sense as all the cables and fuses were the same.

You'll need to disable the split charge relay in the Sargent (or use it simply to signal the DC-DC charger that the ignition is on) and also the built in "charger"

For a new install I'd look more at a 30A charger, the Victron one is popular but runs hot, the Renogy 50A downrated to 30A in the app also and there is the brand new Victron just coming available that @Dellmassive has under test.

If you are replacing cabling make sure you can get the proper high current crimps done, you do not want hot spots behind your furniture.

A 100Ah LiFePo will give you roughly twice the usable capacity and Roamer/Fogstar/Renogy are brands often talked about. You have space (but you will need that for new chargers).so you could go a bit larger on the battery.

Realistically with a good compressor fridge you may get up to 3 days off grid with no charging. To get beyond that you'll either need to do some driving (a 30A charge will refill an 80% discharged 100Ah battery in about 2.5 hours) or have solar that will keep up with your power usage.

What you need to do is some boring planning before spending. Sit down and estimate what powered things you will use and for how much each day to work out your daily power budget.

So to work out your "power budget" make a list of the things you need to power, how much current (amps) they draw and how many hours they will be on per day - add up all the results and that will give you an Ah figure.

For a compressor fridge if we assumed 5A when running so for a day a rough estimate would be:
5A x 0.4 x 24 = 48Ah

You now see why everyone talks about fridges. Anything to do with heat (either heating up or cooling down) uses a lot of energy. And why there are so many tips on maximising run time by pre cooling and maybe freezing some items.

I've seen folks mention figures of fridges running about a quarter of the time which results in a slightly better figure of 30Ah - but lighting loads are going to be much lower and the fridge will dominate the calculations so maybe use a more worst case figure.

I think if you can add solar that will increase your runtimes - a nominal 100w panel is going to put in around 5A in good sun, so an 8 hour day may replace all the fridge used.

 

[roadtripper]

Personally I'd stay away from the inverter unless you are certain you need it and are willing to spend the money to support it.

The vast majority of loads these days are or can be serviced by 12 or USB.

If you are dead set on the 2000w inverter then you will need either at least 2 x 100Ah LiFePo batteries or one of the massive seatbase 200+Ah ones as it will be a 170A load and even a good 100Ah LiFePo can't sustain that.

You also have to replace that charge somehow as you are off grid.

So if you run the inverter for 10 minutes to power a 1200w coffee machine you'll use (assuming 80% efficiency)
(1200w/12v)/0.8 = 125amps
125/6 = 20Ah of capacity

So your espresso has cost you the same as:

• A day of running the fridge
• About an hour drive
• About 4 hours of strong sunlight on a 100w solar panel

It's only when you try and generate power for mains appliances yourself you understand the sheer amount of power flowing through the National Grid into our homes that we take for granted...

 

[The Flying Scotsman]

ok thanks I won’t bother with the 2000w inverter. It will be too much for the occasional use it would get.
So I’m looking to get the biggest lithium battery I can afford,
Replace the split charge with a B2B charger,
And upgrade the solar charger to MPPT
The Sargent is used for my fuses as well so if I can keep that I would.
Also is my solar panel ok or will that need upgrading too?
It a THQ compressor fridge I’ve got

 

[roadtripper]

What rating is your current panel?

You also need to consider EHU charging. You will need to disable the "charger" in the Sargent - it won't charge a LiFePo

If you mostly do off grid and charge from driving or solar then that may not be an issue but otherwise you'll need to add an EHU charger, maybe a Victron, and you'll need to find a place to wire that into the EHU mains (downstream of the breakers)

 

[The Flying Scotsman]

What rating is your current panel?

You also need to consider EHU charging. You will need to disable the "charger" in the Sargent - it won't charge a LiFePo

If you mostly do off grid and charge from driving or solar then that may not be an issue but otherwise you'll need to add an EHU charger, maybe a Victron, and you'll need to find a place to wire that into the EHU mains (downstream of the breakers)

I’m not sure what rating the panel is. And I would still want EHU charging
I will start researching all these bits I need to buy and dare say I will have more questions.
Thanks for all your help so far.

 

[Rioja John]

@The Flying Scotsman here’s my 240v and 12v install my van is a 6 seater day van with Van King bed and sliding tray, I’ve built a plywood box covered with stretch carpet, I've installed a camping 240 system, 2 100ah lithium batteries, buss bars, fuses, Victron 30 amp charger, 1500watt pure sign wave remote control inverter which I’ve wired 2 external sockets from on 3 pin plugs plus battery isolation switch.
I’ve also installed fuse boxes which feed my diesel heater, interior lights, 12 volt sockets and usb sockets around my van.
I’ve also fitted a Victron MPPT solar controller with Anderson connectors so I can just plug in my 200watt portable solar panels to Either charge the batteries or my 1000watt Jackery power station. I have also got under my drivers seat a 30 amp Sterling B to B .
I’ve installed this system as we run a portable Alpicool TWW35 fridge, my CPAP machine, a low wattage kettle and a small slow cooker, we have a Berghaus air awning and we do all our cooking and living in that and use the van for sleeping and change of clothing.

John.

 

[The Flying Scotsman]

@The Flying Scotsman here’s my 240v and 12v install my van is a 6 seater day van with Van King bed and sliding tray, I’ve built a plywood box covered with stretch carpet, I've installed a camping 240 system, 2 100ah lithium batteries, buss bars, fuses, Victron 30 amp charger, 1500watt pure sign wave remote control inverter which I’ve wired 2 external sockets from on 3 pin plugs plus battery isolation switch.
I’ve also installed fuse boxes which feed my diesel heater, interior lights, 12 volt sockets and usb sockets around my van.
I’ve also fitted a Victron MPPT solar controller with Anderson connectors so I can just plug in my 200watt portable solar panels to Either charge the batteries or my 1000watt Jackery power station. I have also got under my drivers seat a 30 amp Sterling B to B .
I’ve installed this system as we run a portable Alpicool TWW35 fridge, my CPAP machine, a low wattage kettle and a small slow cooker, we have a Berghaus air awning and we do all our cooking and living in that and use the van for sleeping and change of clothing.

John.

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Thanks that looks a decent set up.
What I think I will up doing is sorting my 12v system so it runs for longer and then buy a stand alone inverter that I will just charge before I leave if I’m going to use 240 plug ins.
Think I would rather have 1 or 2 lithiums and a decent solar system for the van then the portable inverter power station thing later if I decide I need one.