DEEP CYCLE BATTERIES and BUSH POWER

[condor22]

Firstly,the size of a 250W panel, my van is only an 18 footer (A/C, large main hatch, shower vent and Winguard antenna) wouldn't fit. 2nd, a 250W would weigh about 16kg or more, whereas the panels I'm putting up are about 3kg each. Next, a framed panel is at least 35mm thick, needs to be mounted on legs (brackets) at least as high off the roof, changing the aerodynamics. The only way I can get 200W is to use 2 panels and each would be at least 10 to 11kg adding up to over 20kg (not including fixings)

Also, I am reluctant to fix brackets to the roof for a panel, my first van had a panel bracketed to the roof, it developed a leak on 2 of the brackets near the outer edge. The panel was over the overhead cupboards of the lounge and was not detected until the damage was done. The flat panels glued on aren't visible from the ground and would minimise if not eliminate any change to aerodynamics.

I also had to remove bird nests on several occasions and it was difficult to clean under them.

But, mostly that I estimate, 30% more output from these panels over mono crystalline based on the concertina panel I already have, which uses these cells.

Finally, my choice......

 

[Tathradj]

And also you have redundancy if one panel goes AWOL,
Also you have to have a certain type of controller to step to 12v from 24,
Some type do it automatically but generally not an off the shelf item.

 

[condor22]

No I don't Tath, The panels are connected in parallel, so the V output is 12V nominal not 24, the A output is doubled i.e each panel produces, say 6.5A then in parallel total output is 13A.

Solar controllers do basically 2 things, they step down the fluctuating voltage of a panel from between approx. 17 & 20 V to a stabilised charging voltage (nominally 14.5V for an AGM) and secondly use that voltage to charge a battery. Good ones like the one I'm using are a 3 stage smart charger.

The one I'm going to use is a MPPT charger which the dealer will re program to the best algorithm for my AGM battery re Boost, Absorption and Float outputs.

But yes, definitely correct re redundancy. The circuit breakers will protect and isolate each panel and the regulator input @ 10A each, but I'll probably put a 20A fuse in the line from regulator to battery as well.

If I'm out during a lightning storm I can trip the breakers to disconnect them just in case. Probably wouldn't be producing much in those conditions anyway.
Also, if I need to remove the battery for a short time, the panels aren't thumping the regulator input if tripped.

 

[condor22]

I'm told by this guy doing my panels that he did a larger van as follows;

6 x 200W panels
3000W pure sine wave inverter with auto sensing (if connected to mains the inverter is auto disconnected, if not connected to mains the inverter auto senses this and provides 240VAC to the van)
2 x 300 AH AGM batteries.
A reasonable sized 12V compressor fridge (not sure how big, but 150lt plus)

If the guy wants to boil water for a brew, he uses the electric kettle, the microwave to cook and can even run the air con off the inverter.
He was up north and whilst driving, had the aircon on in the van using the inverter, because the panel input was more than what the inverter used to power it. Plus a Redarc putting in more if needed from the vehicle. So when he stopped the van was already cool.

The only thing in this situation is that the aircon is switched off whilst the kettle is on (short time period) But pretty well every 240VAC appliance could be used from the inverter during the day and a reduced capability at night.

He has 150AH of battery power overnight @ 25% of capacity.

What I'm doing is nowhere near that, but it will allow me to go off grid and not run a genny at all unless I want to. Most National Parks won't allow generator use.

 

[condor22]

Solar Panels installed 2 x 100W, 20A controller and 2 x 10A "NoArc" circuit breakers. The supplier installed the panels and wiring through the roof, I wired up the internals.

My first test was to run the battery down yesterday, so; AGM Battery capacity = 120, used 33% = 40AH. 40AH is more than I would normally use. Most solar panel cells react to visible light only, these panel cells also react to infra red (sunrise and sunset) and ultra violet (between sunrise and sunset) as well as visible light. So they start working at dawn and finish at dusk, so longer hours.

Weather conditions - hazy and partial cloud, but the sun was shining most of the time, cool. The circuit breakers were switched on after dark the night before.

Results (from my BM PRO monitor) BAT C = Battery temp, BAT V = Battery Volts, CHG A = Charging Amps. I can assume the battery is properly fully charged when the controller enters float mode. This controller's float V = 13.3. The boost stage puts most of the A in fairly quickly, the absorption stage (the last approx 10%) can take upwards of 5 hours. The controllers A & V will vary depending on what the sun is doing as well as the Latitude (sun angle)

TIME----BAT C--- BAT V----CHG A
0930-----13-------13.6-------6.0
1000-----14-------13.6-------8.1
1030-----14-------13.8-------9.5
1100-----17-------14.2------10.2
1200-----18-------14.5-------4.3 (Absorption)
1230-----19-------13.3--------0 (Float)
Fully Charged

Of note - The solar controller is a 3 stage smart charger, its float voltage is 13.3V, the A in float mode is variable. Why? - If I am using, say 4A, from the battery this controller will adjust to provide what I'm using accross the top of the battery, staying in float mode without needing to go to absorption mode. Many cheaper controllers and smart chargers won't. (This is of course if there is sufficient sun to provide the A to the controller)

Photos next post

 

[condor22]

The panels and wiring can not be seen from standing at ground level, so are inconspicuous. They are so flat to the roof there is no wind drag increase.
The panels have a 25/25 Warranty. That is that they are warranted for workmanship for 25 yrs and for output for 25 yrs. Some panels state a 5/25 (and many other variants), that means 5 yrs on workmanship/structural and 25 on output.

The net result of my test is that from dawn to 1230 I "Fully" recharged 40AH, so given that there was at least an equal time left to dusk, and the afternoon sun is usually stronger than the morning, I would expect to be able to charge at least 80AH. I would guess that on a really clear and sunnier day an even better outcome.

The real test will be on a winter overcast day. But that will probably have to wait until next year.

 

[condor22]

The big differences with these cells are;

• Mono and Poly cell output reduces in hotter temperatures, these cells are unaffected by heat,[/*]
• The reason they are smooth black is the cells are rear gridded [/*]
• A 100W mono or poly panel will produce a similar equivalent output to these cells but on an overcast day will have very little, if any, output from dawn until the light increases and the same again going into dusk. Because the Nimbus panels produce power using IR & UV, they will commence output at first light until dusk which extends the time of output.[/*]
• These panels are less than 20% of the weight of a normal framed panel.[/*]
• Almost zero wind drag.[/*]

Price - But as previously stated, you get what you pay for.

Contact -
http://dualbatteries.com.au/index.php?page=home

I have no affiliation with Nimbus other than being a satisfied and impressed customer.

 

[condor22]

The supplier gave me an example of the extent he can upgrade a van/motorhome to be fully independent.

5 x 180 W panels
2 x 300 AH AGMs
3000 W auto sensing inverter.
180 lt 12V compressor fridge and a separate smaller freezer.

The auto sensing inverter is wired into the primary 240 VAC outlets of the vehicle and senses if mains power is connected. If it is, then the inverter does nothing, if it isn't then the inverter auto connects to the batteries to provide 240AC power.

The above, is in simple terms, but provides enough power to run the fridge and freezer, boil an electric kettle several times a day, make toast at brekky, microwave lunch and cook dinner on an induction hot plate. Run TV, lights and pump etc.

Plus if it's hot at lunchtime, run the aircon to have lunch in comfort.

When driving, the above is also supplemented by a DC to DC charger.

That's the kind of setup needed if you are out there 365 days a year, but I'm not, so I'm set up to go out for a few weeks at a time and use different processes to achieve similar results.

My final comment - "How long is a piece of string?" We all have different mobile homes/vans, different needs and wants, different wallet sizes and different ideas.
There truly is not a one size fits all setup, the trick is, do your research and work out what you want to do before buying a solution.

 

[condor22]

Hi,

My caravan is now all set up for what I want to get out of it. But before I summarise, I've been doing a bit of research in particular with the guy at Nimbus where my panels were installed.

I've stated that one should aim to average the depth of discharge of a deep cycle battery (in particular an AGM) to 25% of capacity. This is largely the case, but primarily aimed at those using them all day every day. In other words, the Grey Nomads living the dream or those of us lucky enough to detect for months at a time and living out bush. Bugger, I'm not one of em!

However, if like me, you use your camper, caravan or motorhome for 2-3 weeks, 3-4 times a year, my advice is that from a years of use perspective, up to 50% would be ok and still give 8-10 years of battery life if not more. I say this only if the battery is being properly charged and left on proper standby charging when not in use.

So I can extend the 30AH from my 120AH AGM to more like 60AH, if I need it. But also will need to charge longer if I do. Having done some more testing, there will be times I'll need close to that depending on what I use.

I'll summarise the equipment, process and loads I use.......next post.

 

[condor22]

My latest additions

The solar controller is a 30A regulator/charger.

The PVR is a Kogan twin tuner, that allows 2 Ch to be recorded and is connected via HDMI, whilst I can watch a 3rd Ch on the TV DTV. It pulls 15 W and works well on my 150W inverter (pure sine wave). Yes I know I'm not out there to watch TV, but if it's pouring rain n freezing cold, I will.....

I've also purchased a small 12V Johnson pressure pump @ 4 odd litres a minute. This I will use to pump water from my jerry cans to the van tank when replenishing water. Lifting and holding 20kg whilst it gravity feeds to the tanks was not my idea of relaxation, especially as I had 3 jerries for the 60lt.

More..........

 

[condor22]

My logic for providing power, which has evolved based on my van type and my needs, is broken into several categories.

• What I need when driving and towing the van,[/*]
• What I need and want when on a caravan park,[/*]
• What I need and want when bush camping, and[/*]
• To a lesser extent if in a National Park and unable to run a generator.[/*]

(Most of my travels are in winter time)

Towing - The only thing running is the 3 way fridge, it pulls near 14A, is connected to the Van battery and has a motion detecting switch which disconnects when not moving. This prevents the Van battery from being flattened.

The original connection, via an Anderson plug to the car, suffered too much voltage drop (<12V) and relied on the alternator to "charge" the van battery. In my opinion it was a poor method and did not do the job properly. Solution - a quick re-wire and installing a Redarc BCDC1220 next to the van battery. The Redarc will work at 9VDC so when charging mine gets 11.8V at input, but will charge and manage the AGM correctly and more than what the fridge uses.

Yes - now I have solar that will also help, but will not provide enough charge in bad weather, and.
Yes - I could rewire the car and the van with heavier cable to reduce voltage drop, but that is a major job. The voltage from an alternator is not enough to properly charge an AGM, so providing the wiring is heavy enough to run the Redarc (which mine is), it's a lot less work.

N.B. If I stop for more than 20 minutes, I switch the fridge to LPG and then back to 12VDC when I set off again.

Next - Caravan Park

 

[condor22]

Caravan Park - on 240VAC mains.

The van I have is fitted with a transformer/charger. There are also 2 switches next to the LED voltmeter. One is a switch between the battery and van loads to isolate the battery. It is connected between the battery and the transformer, which distributes power via 3 circuits to the van and another to the fridge. The second switch turns the transformer off, when on battery power. All lights, range hood, fans and pump are 12VDC. The only 240VAC items are the air conditioner, hot water system (duel LPG), microwave and GPO outlets.

The transformer is set to output at 13.8VDC, which is also it's charging voltage and again not suitable for an AGM or GEL battery. (The original van battery was a 100AH GEL deep cycle.) So, I replaced the GEL with a 120AH AGM and added a Projecta 15A Intellicharge smart charger and another switch next to the above mentioned 2 switches, to switch the Projecta.

When on mains 240VAC, I switch the battery OFF, the Projecta ON and the Transformer ON. (same setup at home, connected to my mains power) The process here is, that the transformer provides 12VDC to the van lights, pump etc. including the TV - the Projecta keeps the battery at FLOAT and under no load because the battery switch is OFF.

On 240VAC mains, it does not matter what I use as it's all provided by the transformer, except the diesel heater which is connected directly to the battery, bypassing the battery ON/OFF switch. I did this rather than grab power from the transformer to avoid overloading the transformer circuits. Any power the heater uses is provided by the Projecta, keeping the battery at FLOAT.

The important bit - Bush Camping/NP.

 

[condor22]

In the Bush (the only difference when in a National Park is that most won't allow generator use.)

The first topic is, the options to charge the battery and note the fridge is now running on LPG.

My options are;

• Solar (as noted previously) 2 x 100W panels via a 30A regulator/charger,[/*]
• Generator, via the Projecta, and[/*]
• If needed, connect the car via Anderson and idle.[/*]

I would, now normally rely on solar and monitor battery state via the BM PRO app on my smart phone. Today is a pretty dull overcast day and at about noon, I put a 4A load on the battery and was still putting in +2.5A. Keep in mind the battery is full and the charger is still in FLOAT mode, so if I was 25% or more discharged, the input should be higher.

If I've used more than solar inputs, I can crank up a genny later in the day and if on a NP connect the car in its place. I haven't been out in the bush since the panels were installed so time will tell.

My usage will vary, however, during the day it will normally be be very little as I'm out digging holes. At night time, running LED lights for say 6 hours, the TV for 5 hours and the diesel heater for 12 hours, I estimate about 35AH. If I use the DVR on the inverter, add another 1.5AH per hour. Plus on a zero or sub zero ambient night maybe another 8-10AH for the heater. So my worst case scenario is <50AH which is a bit more than 40%.

As stated time will tell, I still have space for another battery to double capacity or I can interconnect my 100AH 4x4 auxiliary if needed.

 

[condor22]

For now, that's all I am going to write about on this thread. I've enjoyed doing this and in some ways, by writing about it, I've also helped myself formulate my course of action, re my own van.

I will close by saying/resaying 3 things;

MY WAY MAY NOT BE YOUR WAY, TAKE FROM IT WHAT YOU WILL,
YOU GET WHAT YOU PAY FOR, and
I'M HAPPY TO ANSWER QUESTIONS.

Mike

 

[Macca50]

Mike great post and thread your effort,knowledge and information is appreciated.

Cheers.

Macca

 

[condor22]

Like I've said before Macca, this is what I've done, it doesn't suit every application or person. But it may help the average layman or should I say lay person, to understand it's not just hook up a battery and go for it.

There are dozens of ways to go about this topic, this is just one of them. But I do stand by the science etc......

 

[Guest]

I have had and experimented with solar etc.etc.etc. My old van has 2x200w panels@ $207 each. Each has a 20A regulator. The ones I buy off ebay for less than $20 have settings for VLA/SLA Li-ion and many more. I can put 3x n70zzs in the van battery compartment. I use car batteries from the recycler-$5 each. Take em home, top em up charge em and try em. No good I take em back and swap em for free.. I have jumper lead wires running outside so I can hook up as many batteries as I can get my hands on. So I can even run my 240 volt air compressor if need be. Joiner leads are made from cut up jumper leads with crimped and flattened copper pipe for the terminals. Also just invested in a proper battery tester off ebay ($30). My inverter is 3000/6000w pure sinewave. At auction for $226. Water pump under the sink 12v/ 60l/min($65) through big double filter($35), can draw from tank, tap or dam/river. I have the 3-way fridge, a bar fridge and 2 Engels(big/small) Air con is Bonair profile converted to 12v with car thermo-fan(free) and pond pump($5) ,and controllers($5ea.). It has a float in it and is hooked to water supply(old gravity HWS float). HWS is gas instant mounted outside door-comes off quickly for travelling. Shower head right there too.
Inside lights are 12/240v LED and external/surround solar garden lights with larger capacity batteries installed, doubling their run-time
I have a wind generator made from a 110vdc exercise treadmill motor, with ceiling blade fans(all free salvage). About 400w@ 12-14v in a stiff breeze. It drives in through a Colemanair diversion controller($100ebay) and has a load dump resistor coil($40). It can mount on the back of the van or stand alone. Also have acquired another of these dc generators now-yet to set up-maybe fans or maybe on a small petrol motor. This and more can be regulated through the Colemanair, with extra relays, up to 200 amps/5x40amp relays.
23"Flat screen TV($49 at Auspost shop), Vast satellite($249)dish and eye($45total-ebay).
4 stroke 800w genny and 4A battery charger for emergencies.
Also have various fold-up panels to hook in extra, or drive separate battery(s) for filler pump, dry blower shaker motor etc.
I lived in the van at Milparinka for 2 years.

The science is not above me, it is my servant. If I burn something out or it's not enough capacity I get around it without spending big bikkies or paying someone an exponential price for their goods or services. No matter what, I could never justify that. Better to learn it yourself than pay someone and learn nothing.
One thing I have learnt for sure is all this stuff can cost ten times what you can buy it for if you do your homework.

Down the track I will swap out the lead-acid batteries for a bank of 2500 mAh, Li-mn High drain 18650s. 3 per series(11.1-12.5v), 10 series' , $1.52 ea=$45.60 per 25Ah(?). To cut down the weight. Another 25Ah every time I can spare $45.60. My solar controllers can be set to charge these properly.
Some of the local thieves want $13 each for these batteries. That's $390 for 25Ah!!!

Yes, I'm a rough-as-guts bushie. And bloody proud of it!

If I can get an electric start lawnmower from the dump I will set up the spare treadmill motor on that and have it auto-starting/stopping via relay(s). Low power through variable resistor driving(N/C) start relay. Load dump from Colemanair driving(N/O) stop relay. Easy-peasy.

 

[condor22]

The only person you need to please in this game is yourself

 

[condor22]

Here are some stats on my solar setup, I'm out bush as I write.

A couple of days ago it was coldish overnight. I watched some TV, ran the diesel heater all night, water pump for 2 showers, lights etc and used about 38 AH.

I left the solar panels on overnight so that they would be connected before I woke up. By about 1.30pm the battery was full.

The weather was about an hour of some sun, the rest of the day was dull, cloudy overcast with occasional rain. About as bad as it can get for solar input (apart from night time lol).

So the investment was worth it.

Oh I also charged my laptop, phone and the GPX battery from the van battery as well.

 

[bazxa]

Good setup and great info. thanks