DEEP CYCLE BATTERIES and BUSH POWER

[condor22]

The link for Nimbus, but you will probably need to contact Michael, he may have photographs he can email and other details.
He is not the cheapest, but it is quality gear.

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

I should mention how Solar panel warranty works. You may see it noted in this format 1/25 or 2/25.

What this means is a 1 or 2 year manufacturing warranty and a 25 year performance warranty. Very few give a 25/25 warranty which is 25 years manufacturing 25 year performance. I seem to recall that Nimbus do have some panels with a 25/25 warranty.

So, the Ebay link you have above shows a life span warranty of 8 years, it doesn't say it is a manufacturing warranty and if it's 8 years on performance, then that is crap.
As I've said before, you get what you pay for.

 

[condor22]

Thought I'd post my latest mod to my Caravan.

The original Transformer/Charger is not ideal in my opinion, but for now I'm stuck with it. It does provide the van 12 VDC power when at a van park or at home and it does charge the battery after a fashion. The charge voltage is 13.9VDC which is a fraction low for a GEL battery (should be nearer 14.1V).
The GEL battery is also not my first choice, I would rather an AGM, but this charger states it is not suited to an AGM, they require nearer 14.4V charging), so for now I'm stuck with it also.

My greatest concern is that, when I measured the voltage coming in from the car through my Anderson plug connection, it was only 13.6V. Even though I am using 6mm twin cable all the way, there is a voltage drop. This transformer has terminals for the car connection, but does not boost or charge the battery, it is purely a connection through to the battery. When driving, the 3 way Thetford fridge is drawing between 13 & 14 amps from the van battery, which is supposed to be charged from the alternator. It is not, in particular the voltage is not high enough and after driving for 8 hours on my last trip, my fridge which started at 2.4 deg C was running at 9+ deg at the end of the trip (the ambient temp was high 20s). So on a hotter day, I'd lose all my food, as it was I lost the frozen food.

So, I've done the same in the van as I have on my 4x4 auxiliary and connected a Redarc BCDC1220; here are the pics.

This is the original Transformer/Charger

The new Redarc Charger - note the legs I added, these things can get hot, vinyl laminated timber is not a good thermal conductor. Couple of pieces of Alum angle riveted together allow airflow around the BCDC.

The BM-PRO battery monitor, previously described

I've added an outside 12V connection, 1x cig socket and 1x Merit socket. This is 2 way, in that I can take power out, but also feed in my portable solar panel output.

More.....

 

[Jaros]

Well done, can i ask what make van it is??
Jaros

 

[condor22]

I hooked up the car, ran the engine, with the van connected, the battery was 20% discharged.

The BM PRO showed that the voltage was 14.4 (boost) and the current going in was running at 14.5 amps.

Which now satisfies me that the fridge will get all the power it needs and the battery should be full when I get where I'm going.

As an aside, if I stop, there is a motion sensor on the fridge wiring which cuts power off when stopped. So at a servo for fuel for 5 minutes, I ignore, but if I stop for lunch i.e. 1/2 hour or more, I switch the fridge from 12V to Gas so that it keeps the temp down (more critical on a warmer day)

Here's a point some may not know, if on a colder day the fridge is still holding at 3-4 deg with no power or gas on it, you may think, "great".
But, it's the freezer that is more important, whilst the fridge is holding temp, the freezer most likely isn't. It takes a lot longer to raise a fridge from 3 deg to say 10 deg if that is the outside temp than it does for a freezer to come up from -20 to +10.

So whilst your milk is ok, you frozen food may not be frozen. This is all while the door is shut and worse if opened.

I found this out the hard way. In my last van, I had a Dometic 3 way on gas, the overnight temp was below zero and my fridge was freezing, so I switched it off.
The next morning my fridge was still showing just over 1 deg and my frozen food was almost thawed out.

The pains of a gas fridge

Conversely, my Engel which has no freezer, I did switch off overnight, because cans of beer and Bundy don't react to well to being frozen and they were still cold the next day.

The conclusion I draw here is, apart from monitoring power as I've previously noted, fridge temps also need monitoring - it's bloody hard to know what you got otherwise.

 

[Redfin]

Hi Condor, I was always under the impression for dual battery systems etc that you should use 6 B&S, not 6mm twin core, to avoid voltage drop over a distance.

 

[condor22]

Well done, can i ask what make van it is??
Jaros

Jurgens Skygazer

 

[condor22]

Hi Condor, I was always under the impression for dual battery systems etc that you should use 6 B&S, not 6mm twin core, to avoid voltage drop over a distance.

Yup between 2 batteries under the hood both being charged by the alternator, you would.

However the BCDC1220 is not only a 3 stage charger, but a booster as well, it's input range is 9 to 30VDC, but it gives the correct charging algorithm for a GEL or AGM deep cycle battery.

FYI, my van battery cable totals 7 M from source at the car to the van battery, the voltage drop @ 50C ambient temp is 0.44V @ 7.9W so not enough to overheat the cable.

But far more practical to run under the vehicle kick strip. Also, the van Anderson connector cable is what Jurgens provided and it is also 6mm sq.

 

[300]

Hi Guys I've just set my camper van up with a 105 ah battery and a portable 140 w solar panel Iam running a 35 lt fridge on 12volt and a 15in tv and one led light tv also 12volt Iam wondering when I get home from a trip 2-3 days do I charge my batteries up to full charge with a smart charger Iam yet to buy for the next trip and do I keep them charged up even it might be 2-3weeks before my newt trip or wait just before I do go on the trip then charge it's all new to me need advice .Thanks

 

[slowflow]

Keep them charged.

 

[Guest]

Keep them charged.

and cycle them , use the charge and recharge, use the charge and recharge , a battery kept at peak terminal voltage will not have the stamina of a cycled battery

 

[Westaus]

If you are looking for the best guide to read on the forum for Batteries then look here - https://www.prospectingaustralia.com/forum/viewtopic.php?id=9156

That should/will answer your questions and some. It covers battery maintenance also depends on the type of battery as well.

 

[jon_m]

Condor22, Thanks for your thread, its work and sharing your knowledge & experience.

Like to ask a general charging question based on this understanding, if correct; The life of deep cycle batteries depend on time, heat, depth of discharge, quality of charge etc but also on their number of cycles. On this last criteria is it a correct presumption that its best to NOT leave an AGM mounted in your car when not necessary, as each time you go for a drive etc you are effectively cycling the battery?

Re my circumstance; I bought an RACQ 105ah AGM together with a Ctek MXS4CA 8 step charger a year ago. The RACQ man said to leave it on all the time when at home. Just recently bought and wired in a Ctek D250S Dual, in a way I can readily transfer it to some other vehicle. But am thinking I should not be leaving the battery in the car with it ??

------
Incidentally, while researching 'how & what' I noticed that some people were having issues re running solar panels with their D250S, with the problem being that this charger has a built in regulator and there can evidently be issues of the battery not being charged (fully or at all?? cannot remember!) when connecting solar panels with built in regulators!?
http://www.baintech.com.au/faq/why-wont-my-ctek-d250s-dual-charge-from-solar-panels

 

[condor22]

Hi Jon,

I'll answer in brief all of your points;

• Yes life of battery is dependent upon the criteria you note. Will re-explain [/*]
• AGMs love to be left on charge all of the time, however there is a concern I'll explain.[/*]
• I have no experience with CTEK chargers only Redarc DC to DC chargers, but they are similar in function so I'll explain below.[/*]
• Again re the D250S, can't speak for it, but, using a solar panel with a built in regulator, then connecting it to another regulator is not the correct method, again explained below.[/*]

 

[condor22]

The primary factor in life of a battery is depth of discharge. Here's a chart.

You can see that at;

10% = 5,000 cycles
25% = 2,000 cycles
50% = 1,100 cycles
80% = 500 cycles

What this means is that if fully charged to start, you use 25% of capacity i.e. 25AH from a 100AH AGM, then you charge it, this = 1 cycle. If you assume that you cycle once per day then;

10% = 5,000 days = 13.7 yrs
20% = 2,000 days = 5.5 yrs
50% = 1,100 days = 3 yrs
80% = 500 days = 1.4 yrs

Most people running a fridge such as Engel or Waeco will use between 25AH and 50AH. Here's an example of the difference in these 2 fridges brands. The Engel 40 litre is rated up to 2.6A, the 40 litre Waeco is rated at 7.0A. You then need to look at how long the compressor is working in each fridge under the same conditions.

I can only speak for Engel, I know my 30 lt Engel uses 25AH in 24 hours @ 25 deg C ambient, but more like 45AH @ 40 deg ambient. I can't speak for Waeco or other brands.

The big thing is; you need to know what you are using, i.e. monitor use, to know when to charge, to maximise battery life.

My 4x4 Auxiliary battery is in draw system in the rear cargo space, it is currently a 100AH AGM. When I replace it, I have the space to fit up to a 130AH AGM.

My AGM is charged by a Redarc BCDC1220, which is permanently wired into the 4x4. So it is on charge every time I drive. I only turn the Engel on when using it. I use it all day every day when out bush and occasionally for social functions at home. At other times it is off.

Several years ago I had a caravan with 2 x 100AH AGMs in it, I had a 3rd 100AH AGM I could temporarily add when needed. This 3rd battery is the one I now have in my 4x4, it is at least 6 years old and still going strong. Why, because I don't cycle too deep, I know what I use and charge accordingly.

That answers the first 2 points. I'll get to the rest later today......

 

[condor22]

I'll add a little to the above,

When I'm driving, I am charging my Aux battery with the BCDC1220 20A smart charger, my Engel is on and drawing up to 3.0A (@ 30% on/off).

So I'm putting more in than I'm taking out and therefore NOT cycling the battery.

I stop for a days prospecting, say 6 hrs. My Engel thermostat is cutting in to average about 1/3 on @ 25 C, so I have used 6AH approx.
I drive back to camp it charges some of that use. Camp up overnight, (15 hrs) no driving and the Engel uses another 5AH.

If I only drive for say 1 hour, I'm not going to put all of the usage back in, because smart chargers in Absorption mode, have a reducing current (amps).

To overcome this, when I park up to detect, I open a 110W concertina solar panel on the roof, or windscreen, or ground. It not only charges what I am using, but also the previous overnight use.

I also carry an 8AH 240VAC to 12VDC charger that I can hook up to my generator and the aux battery, back at camp. This also allows me to charge my caravan battery from the other genny outlet.

OPTION OPTIONS OPTIONS

 

[condor22]

Re Solar

Most 12VDC solar panels have an output (unregulated) at about 19 VDC. A regulator then steps this down to the correct charging voltage for a deep cycle battery.

If you then feed this output to another regulator spurious things can happen, such as not charging the battery.

If you have a folding panel with an inbuilt regulator, that you want to use with a CTEK or Redarc solar controller, you need to modify the panel.

There are usually 2 cables from each half of the panel that go to its regulator. Cut these cables at an appropriate position and connect each end to an Anderson plug.

To use the inbuilt regulator, just connect both Anderson plugs. To use a separate regulator connect the panel outlet Anderson to an Extension lead, which then connects to the CTEK or other regulator.

Hope this answers all of your questions.

 

[jon_m]

Many thanks Conder22

Appreciate your answers and very much appreciate the depth & detail of your answers. Seems depth-of-discharge is king for spoiling battery life.

Have another question, please ...

The Ctek D250S Dual I bought specifies a max input voltage of 22 volts and I note many solar panels border this. Like two eBay units go either side of this on the spec;
Open-Circuit Voltage / VOC with the first unit below specifying 21.6 and the second unit specifying 22.13

But the Maximum-Power Voltage / VMP is 18 volts and the second is 17.45

http://www.ebay.com.au/itm/New-100W.../271241288428?pt=AU_Solar&hash=item3f273d9aec
http://www.ebay.com.au/itm/New-130W.../111518057341?pt=AU_Solar&hash=item19f6fe837d

Would the Ctek 'Max input voltage' relate to 'VOC' or 'VMP' ?

I not buying one yet but would love to know for when the time comes, please?

 

[wooly]

Would the Ctek 'Max input voltage' relate to 'VOC' or 'VMP' ?

I not buying one yet but would love to know for when the time comes, please?

VOC

 

[condor22]

VMP is subjective and difficult to measure, so as said above VOC. However VOC of a panel is, with, it not connected to anything and putting nothing but a volt meter across it. The moment you connect a device such as a solar controller to a panel the voltage at the panel will be lower. Only slightly with the device only connected, a more when under load i.e. charging a battery.

19 to 20 volts in, on a 23V max input, is fine, the critical thing is amps. If you connect 240 watts of panel/s (roughly 13 to 14 Amps of actual current) through a 10A controller, be prepared to buy a new controller.

That's the main reason I prefer Redarc kit, the BCDC1220 charger @20A output and the BCDC1225 charger/controller @25A out have an input voltage range of 9VDC to 32VDC. So are more forgiving of voltage drop or spikes than what I see in the CTEK specs.

I use the BCDC1220 in my 4x4 on a 100AH AGM for my Engel and another BCDC1220 on my 100AH GEL (will eventually change to a 120-130AH AGM) in my caravan. The van BCDC charges the battery when driving which is running a 3way Thetford fridge @ about 14A

I would not want to charge at any higher than 20% of capacity and preferably at 15%, which is why I installed a 240VAC 15A Projecta smart charger in the van as well.

The van came with a 30A transformer charger that is not in my opinion a good charger, it wasn't handling the fridge properly on a full days drive. So I use the transformer when on 240VAC to power the van, isolate the battery from it and if needed charger from the Projecta. In the bush I switch to battery and isolate the 2 chargers.

If and when I need to charge from the generator, I use the transformer for van power, and the Projecta to charge the battery which is isolated.
Batteries, even with smart chargers, will always charge better and properly when not under load.

 

[jon_m]

Thanks. VOC it is. Just hate to think if I had one of the panels like in the first (eBay) link outputting VOC 21.6 volts, and then got some sort of spike it could do the Ctek charger in. Maybe there's some sort of voltage limiter (just googled; would that be a zener diode?) that would ensure no voltage above 22 v could hit the Ctek?