12v 600amp hr RV Battery Build Complete!

[CaptainUnderpants]

This would be my first battery build. Things look pretty straight forward, but I thought I would run it by the experts.

I was inspired by this build. From this Thread

But would change up the form factor to be 2 rows of 4 cells rather than one row, so it will fit. Looking something like this.



I was planning on using the following products:

EVE LF304 - Docan Power
Compression Plates from Off Grid Solar Store - These are a little pricey at $199, but would save me time. I could not find another supplier for a similar product. Bottom flange can be bolted to the floor of the van and the Lexan cover can mount on the top flange.

Two - Overkill 4s BMS 120a

Lexan Top Plate Cover - I will have at least a full top plate. Possibly a second stacked top plate separated by spacers to cover either the BMS's or the Terminals if necessary.

Battery Terminals

Source some 1/4" threaded rods and cover with tubing.

The battery will go in an RV. Max charging will be from a 120 amp Stearling B2B charger plus 230 watts of solar. The max draw will be from a Victron Multiplus 12V / 3000 va / 120 amp.

Is there anything I am missing? Maybe plastic sheets between the end caps and the cells?

Just noticed this battery build thread - Similar

 

[ianganderton]

Cool. Interesting project

What are you going to be powering off it?

How many days cover will 800Ah give you?

What fusing are you going to use?

What is the maximum draw these batteries are likely to see

 

[CaptainUnderpants]

Cool. Interesting project

What are you going to be powering off it?

How many days cover will 800Ah give you?

What fusing are you going to use?

What is the maximum draw these batteries are likely to see

It's a 2021 Ford Transit 350 High Roof Extended cargo van up fit by Sportsmobile.


The van is mostly electric, except an Espar gas heater. The high draw items are a water heater, induction cooktop, microwave and air conditioning. Running AC is not really an option unless you have a Godzilla battery bank or the 30 amp shore power hooked up. The other 3 high draw appliances all draw about 1,300 watts, as does the AC, but the other appliances are only used for minutes and not hours.

A typical day off grid uses about 1,500 watt hrs. Currently there is a 12v 300 amp hr battery with a 60 amp B2B charger. So I get about 2 days off grid and it takes 2 hours alternator time to recharge 1 days worth of usage. Upgrading to the 600 amp hr battery will allow a 120 amp B2B charger and double my off grid days to 4+ and cut in half my alternator charging time to 1 hour per day's usage.

The existing battery connects directly to the Victron Lynx distributor through 4/0 wire with a Blue Sea shutoff. It looks like there is a 400 amp class T fast fuse in the Victron Lynx. I will need to upgrade the B2B charger wiring from 4 awg to 2 awg.





The maximum draw the batteries are likely to see is based upon the Victron Multiplus, correct? Sportsmobile put in the 400 amp fuse for the existing 300 amp hr battery. I would think this would also be appropriate for a 12v 600 amp hr as the Victron Multiplus is determining the draw. Correct?

Thanks for posting these questions.

 

[ianganderton]

Cool wagon ?

The high draw items are a water heater, induction cooktop, microwave and air conditioning. Running AC is not really an option unless you have a Godzilla battery bank or the 30 amp shore power hooked up. The other 3 high draw appliances all draw about 1,300 watts

What induction cooktop top is it? I’m looking for something max 2000W ideally with a soft start. Many start at full power and have to be powered down. I have an epever 2000W inverter that seems robust so far but only a 200Ah Lifepo4 battery.

The maximum draw the batteries are likely to see is based upon the Victron Multiplus.

Correct but also with any 12V draws added. This can add up with fridge, pumps and diesel heater plus any devices like laptop chargers all going

Another factor can be voltage drop due to low charge in the batteries increasing the amps

2000W/12V = 167A
2000W/10V = 200A

I set my inverter to cut off low voltage at above 12V to minimise this problem. I expect the Victron will have a user setable low voltage cut off too

Upgrading to the 600 amp hr battery will allow a 120 amp B2B charger and double my off grid days to 4+ and cut in half my alternator charging time to 1 hour per day's usage.

That’s a lot of alternator charge!!!! I’m reliant on solar. I drive quite a bit but also park up and use the van as a base for a while so have gone for 480W of solar and aim to live within my means on that front. The only problem is likely to be when I’m snowboarding and so using the heater a lot

The existing battery connects directly to the Victron Lynx distributor through 4/0 wire with a Blue Sea shutoff. It looks like there is a 400 amp T-type fast fuse in the Victron Lynx.

I like my Lynx. Makes a big difference to the neatness of the install. Good to see how well a T fuse holder fits into the Lynx. I think Victron could do with making a battery fuse and cutoff switch module

I went with a battery terminal fuse and mounted my blue sea cutoff switch directly to the Lynx looks and feels very functional, neat and robust.

 

[ianganderton]

Running AC is not really an option unless you have a Godzilla battery bank

I think it’s easy to put a big battery in a van, the bigger problem is replacing the power used. When a lot of power is consumed a lot of power needs generating. Limited roof spec on a van makes for limited solar. Im not a big fan of the slide out panels. I suspect they would be prone to damage in wind as well as heavy as hell on the roof

 

[CaptainUnderpants]

This is the induction cooktop I have. Duxtop Single Burner
Even though this is only a single burner, it is a sizable unit. I am VERY glad I didn't get the double burner. The power draw on this unit is a function of the heat setting. It does not cycle between full power and off while in use.

Yes the 120 amp B2B charger is on the larger end of things. The Ford Transit has dual starter batteries and dual alternators. There is a 175 amp CCP, Customer Connection Point, that makes the B2B charging easy. Sterling makes a newer 120 amp charger that looks good. While solar is ideal, it just can't recharge like an alternator. Plus roof space becomes more difficult as AC and Fans area added.

 

[CaptainUnderpants]

All Done ! Here is the final product.

 

[ma2t]

Nice build! This is similar to mine but more compact. I see the vent on the front but suspect you might need a small fan, possibly on the opposite corner to push or pull air through the unit. For me, the B2B charger can get hot and the Multiplus can get rather warm as well.

 

[Checkthisout]

All Done ! Here is the final product.


View attachment 131084

View attachment 131085

Better than excellent build. Compliments that nice looking van really nice!

Very good work!

 

[time2roll]

Looks fantastic. Great to have that 175a CCP.

I would still consider one large panel for when parked for an extended period. Maybe that is almost never. When is the inaugural cruise?

 

[CaptainUnderpants]

@ma2t, @Checkthisout, @time2roll - Thanks for the Cudos. Battery has been in service for several months now. Working well so far with no issues. The newer Sterling B2B seems to run pretty cool, so that's good. There is 230 watts of solar for keeping everything charged up when parked.