Dual battery vs battery box

[willneill]

It seems the tech and products for dual battery/solar setups are changing a lot at the moment with battery boxes and lithium batteries. Info, products and options online are overwhelming.

I'm looking to run a 30L Engal drawer fridge on weekends and a couple of multi week trips a year.

Plus charge laptop and other portable accessory batteries, so all up not a lot.

My ideal setup would be battery and charger mounted in the engine bay (to save space), two anderson plugs running to the back to connect the fridge and an inverter plus rewiring the centre console and rear cig sockets to run off the second battery. The option for solar down the track would be great.

I don't want to do the install myself and I'm on a tight budget, so maybe a battery box is more realistic.

Has anyone recently done their dual battery install and have any recommendations?

[Greg Grey Grumbly]

I’ve run both the underbonnet second battery in the NT and a separate battery box in my Paj Sport.

The underbonnet was good for space but the heat seemed to destroy the second battery quite regularly, about 2 years maybe three. But it did save a battery box in the rear load area. And I didn’t run a dc dc charger in that setup which probably didn’t help battery life either.

But in the Paj Sport I’ve gone for a load area battery box with a dc dc charger for a couple of reasons, one is the environment is more benign with no heat and engine bay vibrations so the dc dc charger sits with the battery box. The added benefit is that the box can be removed when not in use by simply unplugging the Anderson and the dc dc charger input plug and stored between use.

Both systems work well but getting the second battery out of he engine bay is definitely better for battery life imo.

Greg

[Paj11]

Something like this looks alright, any thoughts?

https://www.4wdsupacentre.com.au/adventure-kings-agm-deep-cycle-battery-98ah-battery-box-ctek-d250se-dc-dc-20a-dual-battery-system.html

[artymr2]

Last camping trip one of the people had one of these battery boxes running a fridge, camp lights, charging their gadgets etc. He did get a better quality battery though (just bought the box) and got those folding solar blankets (200w). It made sense as you can use the battery box in the car or pop it out and use at camp easily. He said the solar panels keep the battery topped up easily when sunny, still very hood when cloudy but the battery would drop capacity over slowly.

I did hear a story about a dodgy battery gassing off (dropped a cell) while in the back and almost gassed out the family. Not sure if you can get boxes (or batteries) where you can vent the gases via a tube to outside the cabin. Similar to what they do for cars that come with battery in the boot.

Cheers

[Greg Grey Grumbly]

The 4WD Supacentre kit looks ok, it gets you a reasonable Capability pretty cheaply.

I used the Kickass battery box and charger combo, It’s a bit more expensive but comes with everything you need such as cabling etc.. It’s been installed 18 months now with no issues, runs the bushman fridge in rhe back for about three days.

Greg

[Bru9]

As they say...once you go portable, you never go back. Having a battery system tied to the vehicle is as silly imo as walking around with a desktop computer when you can just get a laptop.
4wds are disposable for realworld working folk, so why go to all that trouble of installing onboard electrics if the vehicle will be replaced in a measly 10-12yrs???
a good portable battery system can act as an onboard system, yet be unloaded in mere seconds, been proven behyond a shadow of a doubt. yes the engine bay is tempting to use that otherwise wasted space, but you cant install any electrics under the bonnet reliably and there are forever problems with heat n vibrations, really shake my head at dc-dc under bonnet, so make shift. step out of the grungy 20th century and step into the future..
My portable battery box has enough ports, plugs, ando plugs, 240v outlets etc to feed a large family, in addition the dc-dc chargers are mounted on the box, so all i ever have to do when getting any new ride is install a fused neg and pos twin sheath from engine bay to cargo/tray area with ando plug... i have up to 6 50a ando inputs for solar so i can practically never worry about having too much solar down the line.

if your on a budget you will have to go diy route on the box. 100ah lithium, victron 15a mppt, projector or enerdrive 20a dc-dc etc. goal zero have some pretty decent packages but they are pricy and limited in some ways. there much more expensive stuff is pretty respectable.

[Dicko1]

Put a 120 A/h lithium in a battery box and mount a MPPT solar reg to it. Also a dcdc charger. Run 6 b&s wiring from start battery to rear inside of vehicle (suitably fused near start battery). . I suggest lithium as lifting a total of 15kg in a portable box is better than 40kg (120 agm weighs about 37 kg). A few anderson and cigarette outlets and you will be sweet to go. Mount a couple of the dual usb outlets as well....all depends on what you want to use. If going lithium get dedicated lithium chargers...a/c, dc/dc and solar reg.

[Pixie_au]

Ronny Dahl did a recent video on his new set up https://www.youtube.com/watch?v=wTK1mEh2T2Q

This is his unit, which is pretty pricey (hen you still need to do some wiring) but includes a lithium battery and Redarc controller and smart shunt: https://perthpro.com.au/collections/...33193610313837 w.

Other variants here: https://perthpro.com.au/collections/...32977150115949

A few "box only" to choose from here: https://www.nationalluna.com/product...hoC3pEQAvD_BwE

I'm sure many people feel they could make this themselves but the option of just buying one is very tempting.

[Dicko1]

Ronny Dahl did a recent video on his new set up https://www.youtube.com/watch?v=wTK1mEh2T2Q

This is his unit, which is pretty pricey (hen you still need to do some wiring) but includes a lithium battery and Redarc controller and smart shunt: https://perthpro.com.au/collections/...33193610313837 w.

Other variants here: https://perthpro.com.au/collections/...32977150115949

A few "box only" to choose from here: https://www.nationalluna.com/product...hoC3pEQAvD_BwE

I'm sure many people feel they could make this themselves but the option of just buying one is very tempting.

You must like throwing money away if you need to spend $2,500+ on a portable box. I just made one with a 100 A/h lithium, Victron MPPT solar reg. Renogy smart shunt coulomb gauge and heaps of various plugs....about $1250. Add a dc/dc if you want and around $1500 ready to go..No where as big as those in the links you posted either...do it your self...its fun

[hayzelnut]

I've just got the Engel Smart Battery Box (Series 2). It's a really easy and tidy way to do it in my opinion as is has all of the chargers/inverters in to box with a handy battery monitor screen. I actually got a Marine 100 A/h battery as they are "semi deep cycle" and quite cheap. It's not ideal but I can always replace the battery down the track. Cost $780 total (battery box was about $550 and battery $230 on special).

[Peterng]

Things are dramatically changing with dual battery 12v set ups..if you have the coin..lithium..
In respect to your camping and the draw fridge..you should be able to get away with a 60Ahr lithium..$500 or if you are planning for longer trips..then a 120Ah or a.$900 to $1400 for a reasonable manufacturer..
There is the case of getting the proper infrustructure to charge the lithium..the jury is still out..pros and cons on both sides..but seeing you are paying a shed load of coin for a battery and you want to get the best out of it...then yep..lithium profile dc dc charger..with a lithium profile solar regulator..why?..well I like to "sand box" my charging..if a dcdc with a inbuilt MPPT charger goes south..then I can change out that individual component that is the issue..but I still have another avenue of charging..bloke on my latest trip had a dcdc with a mppt charger play up and it was causing him grief.
But that is just me..
Anyway..in respect to a battery box.. if you want to have portability with your power needs go right ahead..plus with the lithium battery.. the battery box will be lighter in weight.
You can have the system hard wired into your vehicle..with the battery in the third seat well..that is entirely up to you.
There are lithium batteries which are designed for under bonnet usage..but in general the lithium battery does not like heat and this will reduce their "life span"..so much so..manufacturers of these "under bonnet" lithium batteries reduce their warranties from 5 to 3 years..plus stick extra "fine print"..some of which..pertains to water ingress to the engine compartment..ie crossing water courses etc..
Anyway..you can still do the same with a AGM battery..yes, it's cheaper in the initial set up costs that is a given..no argument there..but in all honesty if your future camping 12v needs change, you need more usable power capacity or your camping stays are longer and more "off grid"..it's bloody hard to go past lithium.

[willneill]

I had a local battery service quote me up a custom battery box with the following:

- Exotronic battery box with fused outlets
- ATG 100ah LiFePO4 battery (prismatic cells)
- REDARC 25a Core BCDC with mppt
- Victron 375va inverter
- Victron smart shunt
- Wiring loom to run from engine bay to box
$1900

I calculated parts alone without additional wiring to be $1650 retail so I think that's pretty good. I'd wire it all up myself but I don't have the experience and it's not exactly something I want to be messing with.

[Swede50]

Hi,
Have you looked at something like a Bluetti or Ecoflow all in a box solutions.
Some of these things have all you could want in one box
MPPT solar charging
Vehicle charging
240V charging, some can be used as a UPS.
30AMP 12V DC out
multiple USB out
inbuilt 240V Inverter.

Can also be used as a back up at home incase of power failure.
Similar money to what you are looking to spend.

Cheers,
J

[willneill]

Hi,
Have you looked at something like a Bluetti or Ecoflow all in a box solutions.
Some of these things have all you could want in one box

Cheers,
J

I have, the issue is you can't, as far as I'm aware, charge directly from the vehicles alternator via a dcdc charger. When they say 'vehicle charging' they mean via a cig outlet.

This might be fine for some, but I want to be able to quickly and reliably charge while driving.

I also prefer a setup that allows you to change out individual components. This could be if something fails or if your needs change and you want to upgrade something.

The downside to the custom battery box is that you can't charge from AC. I'm looking into this.

[Swede50]

Hi,

The downside to the custom battery box is that you can't charge from AC. I'm looking into this.
[/QUOTE]

I have a battery box with a 100amp Lithium that I add to my fixed system as required.
Also have a 500watt inverter to run of it.

There are many Lithium battery chargers available
I bought a cheapy of Fleabay, 15 amp. Works perfectly and will act as a 15amp power supply when the battery is full.
My batteries have a bluetooth APP so I can monitor what is going on with each battery.
Will charge one or both no problem. Batteries full with two fridges running

I use a all in one solution (200amp battery 2000Watt inverter) for the camper in addition to what I have in the car. If shore power is available then I just plug them all in to 240V.
400 amp of lithium is a bit over the top.

Cheers,
J