12v systems

[shakergt]

just wanting ideas on some nice tidy 12v systems for a camper trailer. What have people done in there campers. I am limited to space so want to do it as neat and tidy as possible. Similar to in the picture. So far I am thinking of using a slim line AGM deep cycle battery. I would use lithium but that means a new dc dc charger. I also want to put in a battery monitor, fuse block, inverter and a isolator.

 

[goody2shoes]

Are you going to use a solar panel?

I had mine put on the roof of my caravan.

I have a deep scycle battery in the caravan that runs all my lights and change up anything I will need

I put in 12 volt lights.

12 volt water pump

Can be off the grid

 

[shakergt]

Yep 160w pannel. Most of my camping is off the grid. The DC DC charger handles the solar no problems.

 

[mudgee hunter]

I just fitted a Amp/ volt meter to a friends set up, that he bought on the net.
Said it was rated to 150amps..... BS!
Cheap Chinese undersized cable etc.
Volt meters don't need heavy cable, but amp meters need all current being used/drawn to run through them. ( unlike a volt meter)
Stick with known brands.
4 pole/ position battery switches are handy.
1# OFF
2# BAT 1
3# BAT 2
4# BAT 1 + BAT 2

Negative and positive terminals fitted with a Anderson plug and short cable makes removal easier.
Fit an inline fuse in-between connections.
The fuse board was purchased from Jaycar. Happy with it.
Also has individual leds that illuminate when blown!
Bunnings are now selling 1m sticks of heat-shrink at a good price too! $2 -> $4.

 

[nucopia]

That picture looks like a neat set up ..cant you copy it or maybe you can look at buying a ready made power management/control board
There are a few on the market
https://www.4wdsupacentre.com.au/12v-control-box.html

https://shop.browndavis.com.au/product/12-volt-power-board-sm-board-1

 

[shakergt]

That picture looks like a neat set up ..cant you copy it or maybe you can look at buying a ready made power management/control board
There are a few on the market
https://www.4wdsupacentre.com.au/12v-control-box.html

Its impressive. It even has a spot for my ctek dc dc charger.

 

[nucopia]

You could do something simple ..
This is what I have in my camper.. 50 amp breaker switch ( can use as on of switch) Solar charger controller , Inverter ,fuse block , negative buzz bar .
I have since added a volt amp metre and wired up 2 x cig sockets in the tool box as well as a 2 x 2 USB and 2 x cig sockets inside the camper.

 

[shakergt]

Nucopia have you got a photo of the amp meter please? I have a 12v guage that I can use to monitor the solar panel v going in and the volts of the battery. It would be nice to see what amps I have in the battery.

 

[goody2shoes]

I had a aml for my solar put into the caravan when I got the deep scycle battery

Should end up with a great little caravan when I am finished

I know I will not get the money back for what I have done to it but I look at it this way it gave me something to do when I had nothing

 

[mudgee hunter]

Nucopia have you got a photo of the amp meter please? I have a 12v guage that I can use to monitor the solar panel v going in and the volts of the battery. It would be nice to see what amps I have in the battery.

Generally to my knowledge, most only show the amount of amps being drawn from the battery.
And % of charge state.

 

[condor22]

Check my 12 V Bush Camping Thread etc....

There are a number of devices that will do both amps in and amps out as well as net SOC. In brief....

1. Redarc BMS -
2. Victron solar controller has an add on that will give some info. -
3. BM Pro -
4. Jaycar power meter. - (needs some calculation to work)
and others......

They vary in price, amount and type of data. Check the web for details.

I'm not one for running devices from the load terminal of a solar controller. Why? - in my instance I have a 20 amp Victron. The rest of my system in the van is set to 30 A i.e. 240 VAC charger, distribution and fuses. The second reason is that it's all well and good to monitor loads and solar input from the controller, but that will not take into account any power put in by a 240 VAC charger, or a separate DC-DC charger, or any loads not connected to the controller.

The reason I went BM Pro is that the device fits on the negative (-) terminal of the battery. Then all - loads and charging are connected to the other end. It has an inbuilt shunt and bluetooth connectivity to your smart phone. Therefore no wires to connect, no holes to drill and no equipment to mount elsewhere.

A voltmeter will give a "guide" to battery state, but is subjective in that if you have a load going at the time the reading will be lower than the battery's SOC voltage and will be lower the larger the load current. An ammeter will give a current reading of load or charge. Using 2 will read both independently, but not record totals or SOC. The primary difference of using separate meters and a BMS is cost, you get what you pay for.

I have the ability to switch all loads and charging on/off. In that, I can then turn a load on and read it's amp draw to see it's affect on the battery. This gives me a guide to what I actually use. I can do the same with solar input (all loads off and the battery below 80% SOC) to see what my panels do in various weather conditions. Similarly with my 240 VAC charger.

The key to all of this is "Management" if you don't manage an off grid system properly, it is doomed to fail. To manage a system, you need to know what you use, what you charge and the battery's SOC. Then have the ability to rectify any short fall.

 

[mudgee hunter]

kool condor!
But for us laymen, can you/ people please not abbreviate too much. Or in brackets use full worded terminology for us newbies!
EG, BMS? (B**** M** S***)
handy for us learn.
erfect:

 

[nucopia]

Sorry ShakerJust seen your post ..the one I use looks something like this..

 

[shakergt]

Battery is in and dc dc charger sorted. I have a few more things to do yet before its completed.

 

[condor22]

kool condor!
But for us laymen, can you/ people please not abbreviate too much. Or in brackets use full worded terminology for us newbies!
EG, BMS? (B**** M** S***)
handy for us learn.
erfect:

My apols, I forget that sometimes, which I shouldn't.

So here are a few

BMS = Battery Management System
SOC = State of Charge
DOC = Depth of Cycle
AGM = Absorbed Glass Matt
LioN = Lithium Iron Phosphate (in respect of these threads a deep cycle battery)

Re the above post from Nucopia. I have a couple of these from Jaycar I got about 14 years ago, only the 30 A version. Great little devices, they measure volts, amps and watts (what they are at the time), also, cumulative Amphours (AH), Watthours (WH), time since last reset and from memory, maybe max and min V, A & W. However,

They are a one way device, so you need to put one on the load circuit i.e. Battery connects to Input and loads to output. Then if you want to know solar input, you need a second one on the charging circuit i.e. Charger to input and battery to output. If you want to know what your net use is you need to subtract load used from charge input. This could be a + or - value and is indicative only if you don't know the condition of the battery to begin with. It will also not take into account any DC-DC charge if it's a separate charger, nor 240 VAC charging.

I have used them, I got fed up of resetting them every day, working out my use and still probably not knowing what the battery had in it. Notwithstanding all the wiring and holes needed in a caravan to use them. Which is why I went the BM PRO, bolt the device onto the battery, connect "all" loads, solar, DC-DC and 240 VAC to the negative terminal. One device, no holes, no wiring, no math, the batteries state of charge on my phone and it does the math. Hey, I got lazy in my old age, lol.

As an aside for those that have the BM PRO, next post.......

 

[condor22]

I have 2 BM PROs, one in the van the other in the 4by on the Aux battery. The app is on my smart phone, but will only connect to one battery at a time via bluetooth. I got a little fed up connecting to one, then having to reconnect to the other. For those that have them, here is my fix.

My old smart phone is a Galaxy S4, my wife's is a S3. I had the BM PRO app on the S4. Last year I retired them both and upgraded them and did a complete factory reset on the S3 & S4, then installed the app on each. Neither have a SIM card as a phone, but the app still works.

So when I'm out bush, I leave the S3 in the storage drawer of the 4x4 and the S4 in the van. Each is paired to the respective BM PRO permanently. If I want to know where each battery is re charge, I turn on the phone, do a check and switch off.

 

[condor22]

Shaker, nice work, can't get much closer to a battery than that, lol.