My MPPT battery box

Gidgee

Active Member
Something I learned recently about solar blankets, some (most?) have panels wired such that if one just panel is in shade you get zero output. It's fine if you are sure the entire blanket can be placed in the sun. Personally I'm going semi flex on the roof, but testing has shown the 100AH AGM can run the 60L Kings fridge for 1 full day not driving at 1C so not in a hurry to fit it - different story running it at -15C where 1 day is a big ask.
 

Bru9

Active Member
Nice work. Portable is the way to go, free our selves of the tow vehicle. Can't ever imagine going back to a vehicle based battery setup.

Just two things id like to mention: 1: That 140AH battery is most certianly not 140AH, the size & weight tell you, Fullriver has the same size roughly and is a genuine 120AH. 2: You would be wise to coat all the exposed metal contacts with some dielectric grease.

It won't be long till your arms tell you to get a lithium, Trust me!


Something I learned recently about solar blankets, some (most?) have panels wired such that if one just panel is in shade you get zero output. It's fine if you are sure the entire blanket can be placed in the sun. Personally I'm going semi flex on the roof, but testing has shown the 100AH AGM can run the 60L Kings fridge for 1 full day not driving at 1C so not in a hurry to fit it - different story running it at -15C where 1 day is a big ask.

All portable panels are wired in Parallel & when one individual panel is shaded a little that whole individual panel is pretty much useless due to very small to almost non existent bypass diodes. The rest can still go on. However long panels like 180-200cm long start to hit shade so easily, I call it one of the laws of shade. Bigger is not better in bush. more square shaped is better.
 

MrPoopypants

Well-Known Member
I feel like a bit of a mug when it comes to solar. I've got a blanket and a hard panel. They work fine but I've never used them in anger! I get 2-3 days out of my rear truck battery with my ARB fridge, so it always gets driven before it runs flat and when we are in the camper, even with two weeks of base camping I just find it easier to switch one battery over with the truck every 4 or 5 days than fiddle with the solar. Only takes a few minutes, with the anderson connections. (the camper has a gas fridge) So my clever planning with my solar wiring etc. has really been a bit of a waste. Just bought a boat, though, so maybe they'll be handy when switching batteries around between all three.
One thing, I upgraded all the wiring and plugs that came with my panels, seemed to make quite a difference with their output, my leads are quite long.
PP
 

Triton14

Well-Known Member
Just two things id like to mention: 1: That 140AH battery is most certianly not 140AH, the size & weight tell you, Fullriver has the same size roughly and is a genuine 120AH. 2: You would be wise to coat all the exposed metal contacts with some dielectric grease.
How can you tell, you cant even see the battery??

This is the battery-
 

Batts88

Well-Known Member
How can you tell, you cant even see the battery??

This is the battery-
On another note I have a 105ah Giant battery 5yrs old it was advertised back then at 27kg these days their 120ah weighs 27kg so why the weight reduction ? A Fullriver 120ah is dearer but weighs 36kg and the Giant 140ah 32kg big difference as I once read weight is a sign of quality when buying a battery. Fullriver hae a good rep for lasting a long time and can be used as a back up to start your car without harming the battery the Giant doesn't.
 

Triton14

Well-Known Member
I guess this applies to any product out there, they can make all the claims they want really but its up to the used to disprove any false claims.
Its a shame their isnt a testing proceedure that products must go through that the supplier/manifacturer must go through before a product can be sold as claimed.

I know there are the Australian standards in place but still its up to the consumer to prove that a product is faulty or doesnt perform as stated.
 

Batts88

Well-Known Member
Yes the standards have dropped off in OZ and the authorities don't care it's all about keeping the economy turning over.

Also when your sales have dropped off and your getting desperate when 4wd action come up with a useless gimmick like parking a 4wd on a battery to maybe cover up for it's other flaws. Who has ever used a battery to bridge a gap in a bush track so they can keep driving the new maxtrax self recovery then run your fridge of it when camping.
 
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SirDrinksalott

Active Member
I have been reviewing making my own battery box as the next project, my intention was to make my own box with a 12v DC DC charger inside to charge from the main battery but with a solar input optional.

But none of you are using a DC DC charger?
 

Triton14

Well-Known Member
I have been reviewing making my own battery box as the next project, my intention was to make my own box with a 12v DC DC charger inside to charge from the main battery but with a solar input optional.

But none of you are using a DC DC charger?
I imagine what I have done can also easily be done with a DC-DC mppt charger, I know kickass does one-

KICKASS 12V Battery Box With 25A DCDC MPPT Solar Charge Controller (australiandirect.com.au)

And that price doesnt include the battery either :eek:

I chose not to used a more expensive DC-DC charger because I didnt need one as I dont have a smart alternator.

In saying that the combined cost of both the isolator & the victron is probably around the same cost as a cheap mppt capable dc-dc charger.


I just chose to go this way at the time & happy with it for now.
 

MrPoopypants

Well-Known Member
I have been reviewing making my own battery box as the next project, my intention was to make my own box with a 12v DC DC charger inside to charge from the main battery but with a solar input optional.

But none of you are using a DC DC charger?
G'day Drinksy,
I've got one Kickass, bought on special a few years back and was great value. Still going great. I made up two others, based on it for my Jayco camper, we use it as a basecamp and I've run it for 10-12 days with no solar. (Gas fridge) Made them so I can swap them with the one in the truck to charge on day trips if I want to. (Compressor fridge in back of truck)
Cheap plastic battery box (I waited to get them on special). Get a big one to fit a bigger battery, some are tiny. Made up anderson leads and plug & go. Using a dcdc in the camper for solar and to keep current healthy on the road. Just screws on top of the box, andersons in and out for car and solar. The Kickass ones have a voltmeter with an off/on button wired in, fits into the lid on most boxes. (another reason to get a big one. Andersons screw onto side. V easy to include usb charger and cig lighter sockets, too. Just drill hole in box lid & wire. KA use circuit breakers, I just used fuses for all active power runs.
Lots of videos on soldering and crimping leads on youtube.
I mainly use the dcdc for peace of mind, that current is regulated and doesn't drop. My truck had smart alternator when I got it and the van has a long run of cable to get inside from the truck.
Of course, if these things aren't a worry, then the alternator works fine but dcdc solar is handy, too.
PP
 

SirDrinksalott

Active Member
G'day Drinksy,
I've got one Kickass, bought on special a few years back and was great value. Still going great. I made up two others, based on it for my Jayco camper, we use it as a basecamp and I've run it for 10-12 days with no solar. (Gas fridge) Made them so I can swap them with the one in the truck to charge on day trips if I want to. (Compressor fridge in back of truck)
Cheap plastic battery box (I waited to get them on special). Get a big one to fit a bigger battery, some are tiny. Made up anderson leads and plug & go. Using a dcdc in the camper for solar and to keep current healthy on the road. Just screws on top of the box, andersons in and out for car and solar. The Kickass ones have a voltmeter with an off/on button wired in, fits into the lid on most boxes. (another reason to get a big one. Andersons screw onto side. V easy to include usb charger and cig lighter sockets, too. Just drill hole in box lid & wire. KA use circuit breakers, I just used fuses for all active power runs.
Lots of videos on soldering and crimping leads on youtube.
I mainly use the dcdc for peace of mind, that current is regulated and doesn't drop. My truck had smart alternator when I got it and the van has a long run of cable to get inside from the truck.
Of course, if these things aren't a worry, then the alternator works fine but dcdc solar is handy, too.
PP

I looked at the Kickass one after watching a youtube and it looked great but the price less battery means all up about $900.

I also didnt like some of the other boxes as they had 1 cigarette style and I liked the 3 on the kick ass so i just figured make my own.

Gianz 125AH AGM = $240
Thunder 20A DC DC Charger = $209
Wire, connectors, sockets, volt meter, wood and handles probably $100.
So all up about half the price?

In regards to wiring, the videos I saw were connected to the starter battery with a 40AMP fuse, I dont need an isolator do I, I take it the DC DC charger can only go one way and the constant draw on the starter battery tricks the smart alternator but what stops the charger drawing when the vehicle is off? Is there a wire to the ignition or something?
 

Triton14

Well-Known Member
I looked at the Kickass one after watching a youtube and it looked great but the price less battery means all up about $900.

I also didnt like some of the other boxes as they had 1 cigarette style and I liked the 3 on the kick ass so i just figured make my own.

Gianz 125AH AGM = $240
Thunder 20A DC DC Charger = $209
Wire, connectors, sockets, volt meter, wood and handles probably $100.
So all up about half the price?

In regards to wiring, the videos I saw were connected to the starter battery with a 40AMP fuse, I dont need an isolator do I, I take it the DC DC charger can only go one way and the constant draw on the starter battery tricks the smart alternator but what stops the charger drawing when the vehicle is off? Is there a wire to the ignition or something?

I have the Gianz 140AH & have been told its over rated & more like 120AH, not sure as I havent fully tested it yet.

Your idea is mostly sound, the DC-DC charge should only flow current one way to the aux or at least have a cut off once the starter drops to a certain voltage, it is essentially an isolator as well, just with more features.

Fusing & wiring size is something you need to look into & will depend on things like how far away from the starter battery it is.

I have a 100amp fuse between my aux & starter but then I can connect the 2 batteries for winching if I want/need to, as my aux is over 3 metres from the starter I am using 4B&S cable which is what Redarc recommend.

Jump over to the redarc site, they have some wiring diagrams that can help

Chargers & Isolators - Wiring Guides | REDARC Electronics
 
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MrPoopypants

Well-Known Member
I looked at the Kickass one after watching a youtube and it looked great but the price less battery means all up about $900.

I also didnt like some of the other boxes as they had 1 cigarette style and I liked the 3 on the kick ass so i just figured make my own.

Gianz 125AH AGM = $240
Thunder 20A DC DC Charger = $209
Wire, connectors, sockets, volt meter, wood and handles probably $100.
So all up about half the price?

In regards to wiring, the videos I saw were connected to the starter battery with a 40AMP fuse, I dont need an isolator do I, I take it the DC DC charger can only go one way and the constant draw on the starter battery tricks the smart alternator but what stops the charger drawing when the vehicle is off? Is there a wire to the ignition or something?
G'day again,
Yeah, I think Kickass look pretty expensive nowadays. They used to have a big pre-christmas sale and I saved a heap, but it would be a lot cheaper to make your own box. Their 8 B&S leads used to be very cheap, too. Solder or crimp, their is a lot of debate about what is best, or you can do both! It's all pretty simple, just sort your tools and some space first, there's a fair bit of cutting of wire lengths, stripping, etc.
I've got a solenoid switch hooked up to my alternator, so I only get power to the rear battery or anderson plugs when the engine is running, but yes, most dcdc chargers have an isolator built in. I didn't bother with a VSR (Voltage Sensitive Relay), just a straight solenoid on and off. They seem to play up less. If you rely on your dcdc to isolate don't forget that the cable to it will always be live, even when the ignition is switched off, as it is still connected to your starter battery end.
Some smart alternators require a power wire to the dcdc in addition to the main power lead, usually wired to the ignition, to tell it when to isolate etc, as the alternator voltage varies and they can switch on and off too frequently. Just make sure you read the instructions and find out what the ouput of your alternator is. Also be aware not all cable is equal. Get quality wire, especially for the long runs or voltage drop can get you.
As I said, I made up two in my camper and one in the boat, the beauty of doing it yourself is you can hunt around and get the best accessories, sockets etc. to suit what you need. Can never have enough usbs these days and I reckon a little round voltmeter is handy, just for an indication of how things are going.
Good luck with it.
Cheers
PP
 

Batts88

Well-Known Member
I have been reviewing making my own battery box as the next project, my intention was to make my own box with a 12v DC DC charger inside to charge from the main battery but with a solar input optional.

But none of you are using a DC DC charger?
I change the battery box in my wife's car recently, removed the pwm charger I had fitted for the solar panel, fitted a Roadtech Marine- Powertech 20amp DC/DC charger to the side of the box they are a fairly large unit only cost $219.
 

SirDrinksalott

Active Member
G'day again,
Yeah, I think Kickass look pretty expensive nowadays. They used to have a big pre-christmas sale and I saved a heap, but it would be a lot cheaper to make your own box. Their 8 B&S leads used to be very cheap, too. Solder or crimp, their is a lot of debate about what is best, or you can do both! It's all pretty simple, just sort your tools and some space first, there's a fair bit of cutting of wire lengths, stripping, etc.
I've got a solenoid switch hooked up to my alternator, so I only get power to the rear battery or anderson plugs when the engine is running, but yes, most dcdc chargers have an isolator built in. I didn't bother with a VSR (Voltage Sensitive Relay), just a straight solenoid on and off. They seem to play up less. If you rely on your dcdc to isolate don't forget that the cable to it will always be live, even when the ignition is switched off, as it is still connected to your starter battery end.
Some smart alternators require a power wire to the dcdc in addition to the main power lead, usually wired to the ignition, to tell it when to isolate etc, as the alternator voltage varies and they can switch on and off too frequently. Just make sure you read the instructions and find out what the ouput of your alternator is. Also be aware not all cable is equal. Get quality wire, especially for the long runs or voltage drop can get you.
As I said, I made up two in my camper and one in the boat, the beauty of doing it yourself is you can hunt around and get the best accessories, sockets etc. to suit what you need. Can never have enough usbs these days and I reckon a little round voltmeter is handy, just for an indication of how things are going.
Good luck with it.
Cheers
PP

Thanks for the advice, just to clarify, does your alternator switch on the solenoid or do you have a switch in the cab? I was thinking like this but with fuses and the DC DC Charger inbetween the Solenoid and second battery, and probably swap out D to wire it into the ignition because I am fuckwit and would leave my lights on if it wasnt for the helpful beep.

I am a pretty competent amateur electrician (famous last words) but I wouldnt want to mess around with the ignition so would probably get an auto sparkie to do that.

dual_battery.jpg
 

MrPoopypants

Well-Known Member
Thanks for the advice, just to clarify, does your alternator switch on the solenoid or do you have a switch in the cab? I was thinking like this but with fuses and the DC DC Charger inbetween the Solenoid and second battery, and probably swap out D to wire it into the ignition because I am fuckwit and would leave my lights on if it wasnt for the helpful beep.

I am a pretty competent amateur electrician (famous last words) but I wouldnt want to mess around with the ignition so would probably get an auto sparkie to do that.

View attachment 70287
Hi again, Sorry if a delay in answering, am in Victoria attempting to cod fish, so not much internet. No need for a switch, instead of D run a wire from an active one that switches on with your ignition. (or the way you have it but you'll need to remeber to turn it off - good luck with that! :) Yes, my dcdc is between C and B. Best practise is not to earth via body of truck, although plenty do. Can cause voltage drop and can have poor earth with resistance - not my opinion but from a few books on wiring vehs, written by engineers. Best to run separate earth cabling. I bought dual 6 B&S in an additional insulation sheath. Tough as nails, but I also added split conduit. I used large mechanical crimpers for cabling, but I think you can get cheap hydraulic press type crimpers on ebay. Pretty handy, as pointed out somewhere above, lots of andersons in a 4wd is very handy. One other thing I did was run a separate 6 B&S cable from the solenoid to an anderson on my towbar to power the camper, makes the 3way fridge run much better on 12v, never melts on hot days. Also handy for compressor to plug into. Don't forget heat shrink, the glue stuff seals much better. Anderson Connect in Vic. have all the bits and pieces separately. Have fun. PP
 

Triton14

Well-Known Member
Re earthing, when doing my research there were 2 camps, run a cable back to the starter or to a point where there is an existing earth.

As my Aux was something like 3.5 meters (cable lenght not straight line distance) I didnt want to want to run cabling that distance back to the starter, expensive & more weight.

A lot of people make the mistake of just bolting to the ute body & on the painted surface, both have potential to give bad earths.

I decided to go to the closest point on the chassis, there were existing bolt holes & no paint, just rubbed it with some sand paper to clean it well.
Worked no issues.

earth.jpg


@SirDrinksalott, if you havent checked out my instal thread yet then check it out for ideas, but I dont think you have mentioned your vehicle type & where you intend toput this box??

My DIY MN Triton dual battery setup | 4x4Earth

Obviuosly the main difference with what you want to do is you want a DC-DC charger instead of the MPPT, as I did do some reading on the DC-DC option the main wiring difference Ican see the @MrPoopypants has pointed out is the connection to the ignition.

After looking at the redarc wiring diagrams again looks likemy above comment about the solinoid was incorrect, you still need one in both of these set ups

BCDC1240 With 12V And Solar Inputs | REDARC Electronics

BCDC Dual with Jump-Start - The New Ultimate Dual Battery Setup | REDARC Electronics

Something else you needto think about imo is being ableto use the aux as an actual aux starter which is half the reason I did my set up.

Its all well & good to just want to run a fridge but if your in the middle of nowhere & you lose your main starter how are you getting home??
 

SirDrinksalott

Active Member
Thanks guys, its a 2011 Hi Lux KUN26R so some site I visited said Toyota Hi Lux post 2006 are variable alternators.

I want a removable box in the tub near the door and I am not too bothered about the cranking assistance as I carry one of those jump starter batteries. I dont plan on moving it around much more than moving it to the door of the tent.

I will have a read of your build thread Triton..
 

soussou

New Member
Dear guys
The maximum voltage of the PWM controller is 50V so if you put two 60 cell panels in series you will smoke your controller. Having shaded and unshaded panels in Parallel will not make a significant difference to the combined output on a PWM controller as the input voltage to the PWM controller is pulled down to the same voltage as the battery charging voltage. The difference between an MPPT controller and PWM is quite small if you are only using one solar panel. Because the charging voltage is similar to the mppt point of the panel. If you have higher voltages and panels in series then the MPPT controller will perform far better than a PWM. But if one panel is in shade, a PWM with two panels in Parallel, will perform better than a MPPT with two panels in series..
You can also need this video for your helping:
 
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