DEEP CYCLE BATTERIES and BUSH POWER

[condor22]

I would think in that instance, providing the smart charger input via an IGN control direct from the start battery would overcome this. That way there is a load on the start battery whilst driving that the alternator should accommodate and disconnect when the engine is off.

Smart alternators, not an area I know a lot about

 

[slowflow]

this link shows how to wire for smart charge alternator.
http://www.batteriesdirect.com.au/shop/product/23370/ctek-d250s-dual.html

I have a 120 ah battery in the rear compartment using 250d. 16mm square from the engine bay back to provide the charger max draw of 20 amps with minimal voltage drop.
Battery runs fridge 3 amps, onboard compressor 30 amps both intermittent loads and a continuous 3 amp overnight load. 250 watt solar panel to the ctek which usually keeps the battery full without needing to run the car. The fridge is hard wired as the cigarette lighter socket connection was unreliable.

 

[mdv]

this link shows how to wire for smart charge alternator.
http://www.batteriesdirect.com.au/shop/product/23370/ctek-d250s-dual.html

Nice setup. 300 Watt solar is 'huge' - that'd be enough to look after a bunch of campers, not just yourself; or to be able to keep ice-creams for your enjoyment after a long day of prospecting!

My CTEK D250S sits in my boot (removable install), having been wired by the auto electrician before CTEK came out with the extra switch to deal with a 'smart alternator'. In fact, I believe back then the auto electrician did not even know that my vehicle had a 'smart alternator'.

I went back to them recently to enquire about retrofitting the extra switch, and his recommendation (based purely on value for money) was to leave things as they are and just ensure there was always a load on the primary battery, achieved easiest by driving with headlights on.

My set-up requires some adaptability between day-to-day commuting, overnight camping with a hiking tent and longer camping with an off-road trailer (and Oz Tent). So, I have wired the vehicle (terminating in an internal anderson plug and an external anderson plug) such that I can have my DC charger and second battery either in the vehicle boot or in the trailer boot, or to remove the battery from the car for day-to-day driving.

 

[SinHof]

Hi All,
First up I would like to thank Condor for his great posts on all things low voltage (12 volt).
One aspect that has me a little confused when it comes to charging a second battery that is connected in parallel with the vehicle crank battery.
It has been my understanding; rightly or wrongly, that two similar batteries connected in parallel would be seen by the charging device as ONE battery.
Can somebody please explain how these newer smart vehicle alternators or other chargers can detect that a second battery is connected across the crank battery????
Toyota Landcruiser 100 series diesel vehicles run two batteries in parallel as standard and in my wagon both batteries are within 0.1 volt of each other most of the time; that said the batteries are never fully charged maxing out at 12.5 volts some hours after a long drive, here again from what I understand vehicle alternators will only charge the crank battery to about 70/80 % of charge at best.
Looking forward to some comments.
Cheers, SinHof.

 

[condor22]

I have not suggested ever connecting an auxiliary battery in parallel with the starting battery. I personally would never do this.

What I have eluded to and will better explain in my future examples is;

Connect the input of 12V to 12V smart charger which is IGN controlled to the vehicle battery (use a relay, solenoid or a smart charger with sensor capability to give IGN control). Then the output of the smart charger to the AUX battery.

All properly circuit protected.

The alternator charges the primary battery when engine on, which in turn powers the smart charger which in turn charges the aux battery. The charger either disconnects when engine is off or in the sensor type when the voltage drops to a point where it is still safe to start the engine.

You are correct re the not fully charging off an alternator, that's why I advocate the smart charger option.

The other benefit is you use a CCA battery to start the car and a deep cycle for the fridge etc. So dissimilar batteries are acceptable.

 

[Redfin]

You can always try a alternator voltage booster.
No experience with them personally, but the folks over at Prado Point give these things the thumb up
http://www.ebay.com.au/itm/Alternat...=AU_Car_Parts_Accessories&hash=item4adfce831b

 

[condor22]

This may work on a duel CCA system, however all it does is boost voltage 5-6 V, which would be too high for a deep cycle battery.

It is still not a smart charger. In a smart charger; BOOST has a variable and increasing to a maximum voltage and a fixed amperage, ABSORPTION has a fixed voltage and a variable and decreasing amperage, FLOAT has a fixed voltage and a trickle amperage to maintain the battery. (the voltages are configured to the battery type being charged)

These stages are what are needed to properly charge a deep cycle battery, wether in car, caravan or boat or the charge source is 240VAC, solar or the alternator.

 

[SinHof]

Hi Condor,
Thanks for the comments; the set-up in the Landcruiser includes a Redarc smart solenoid separating the RHS battery from the LHS crank battery when the engine is not running.
For bush power there is a third stand-alone battery, 105Ah gel cell in its battery box located on the floor behind the driver's seat.This runs the Evacool 68L fridge, chargers for the detector battery and other 12V requirements.
Two solar panels; a 64W Unisolar is mounted on the roof racks and a second 80W is housed in a slide-out mount between the roof racks, this panel has fold-out legs and can be positioned for maximum sun exposure, both panels are connected in parallel as required and connected to the battery via a Morningstar Pro smart solar regulator that has an LED read-out for battery voltage, solar charge current and load current, very handy for keeping track of where the system is in terms of charge/discharge.
The Morningstar regulator is mounted in a clear fronted case and the various connections are via Anderson plugs and cigaret lighter sockets.
The set-up is very versatile in that the whole system can easily be moved and installed in our caravan or to charge the boat batteries.In all the system works very well and has not let me down during a run of cloudy weather or on the hottest of days, its great having the moveable panel as the vehicle can be parked in the shade while the 80W panel is located out in the sun.
Thanks again for all of the information.
Cheers, SinHof.

 

[stevo]

I have a 110ah deep cycle battery in a ArkPac which I connect to a 120w fold out solar panel.

 

[condor22]

OK, here's my first example of bush power design, it is not the only way to do this, it is one way. This one is for a caravan, (the next lot of posts will be for 4x4/tent camping.) I am assuming the following equipment;

Battery = 100AH AGM Deep Cycle
Charger = 3 Stage smart charger, configured to charge an AGM @30amps
Solar Panel = 120W Monocrystalline
Inverter = 300W Pure Sine Wave with internal fusing
Solar Controller = Plasmatronics PL20, 20Amp
12v to 12v charger = Redarc BCDC1220
Fridge = 90 litre Invitrifigo compressor
Load = the rest of the vans 12 volt systems to be distributed.

The PLS2, WY cable and shunt are required so that the PL20 which is 20 amp, can monitor the Inverter which will draw up to 27 amps, I'll explain why later.

There will be 6 images as I build up the system.

The first being a basic battery, charger, load, fridge and fuse system.

 

[condor22]

Now we add a second 100AH AGM deep cycle battery in parallel (I'll explain parallel and series after the example posts)

 

[condor22]

Next- 2 x 100W solar panels are added and their controller

 

[condor22]

Next a 300W PSW Inverter is added

 

[condor22]

Then we add a PLS2 monitor so we can incorporate the inverters drain on the system to the PL20 controller which monitors power in and out.

 

[condor22]

And, finally we add a 12 volt to 12 volt charger similar or like a Redarc BCDC1220

 

[Jaros]

Thanks Condor, it looks quite simple when you lay it out like that in those steps .Thanks mate.

 

[condor22]

Here's the difference between series and parallel

In parallel the volts remain as per battery and the amps are added together, in series, the volts are added and the amps remain as per battery

 

[Jaros]

Do you think you will need to get into Internal Resistances? :|

 

[condor22]

Thanks Condor, it looks quite simple when you lay it out like that in those steps .Thanks mate.

My pleasure Jaros, one of the pitfalls of instructing anything, is I know the subject and can easily forget to break it down for those that don't.

As I have said several times, there are more considerations and many solutions, designs and equipment out there, I don't advocate any one over the other and have no affiliation with any manufacturer (I'm retired), but I do know what works and what is reliable.

The thing I try to avoid is making carte blanche statements, like "I have a 600W inverter, have plenty of power and never had a problem" it tends to infer that it is ok to draw 600W when only a 1/4 of this is actually used. It does not. What I try to do is make the comment/statement and then qualify it i.e.

Given that we should not where practical draw more than 25% of a deep cycle battery system to extend battery life, to provide that 25% to a 600W inverter (at least 50amps) which is running at max, we would need 200AH of battery to provide that power for 1 hour. Then basically draw no further power of consequence whilst the batteries are charged. So I go back to my previous statement, that if you need large power for more than a very short time, use a generator.

Here's a little more on multi stage chargers. Assume we have used 50AH from a 100AH battery and we have a 20 Amp charger. One would assume this then takes 50 divided by 20= 2.5 hours to do. WRONG - The first 30 amps will go in under the Boost cycle and take a bit over 1.5 hours. The remaining 20% (20AH) charge in Absorption mode and can take (typically) 4 hours or so. So the total charge time to go to float mode is 5.5 hours. And, that's using a known input such as a generator.

When using Solar, which is variable, we need larger inputs, over shorter times to cover the worst case scenario of dull, overcast and raining etc.

 

[Westaus]

WOW now I know more than enough to get myself into trouble !

Thanks Condor I have read and learned from every post and every step. I am setting up a spread sheet with what I will be using and all the relevant information you have listed. We will be doing two vehicles over the coming months, so I will update as the job gets done as well.

I know were we have gone wrong in the past now and why we have had some failures with equipment. So this information has been invaluable to me. Those areas will now be rectified and the setup made to work as it should do.

Take care, fantastic posts.

Westaus