To add a extra battery or not to ..... that is the question?

Hi Rusty

John seems to have summed it up pretty well.
to keep your head above water so to speak more in than out is always better.
And more capacity is good for those non solar days will always help.

Geoff

When you add up the costs of setting up with batteries and solar panels, I find it puzzling that few people investigate the other option - gas.

You can run freezers on gas and a fridge. Gas bottles are cheaper than batteries and solar panels. It would take a long time to spend the difference in costs by filling gas bottles.

I little more weight and some storage problems but these are solvable.

With gas, you can stay longer in free camping sites.

bill

The problems with gas remain the same.....

gas certificates and gass fitters required for installation

the maintenance and tempramental nature of the gas refrigeration.

the ventilation required.

The flamable nature of the fuel and all that comes with it

The inability for gas refrigeration to maintain high temperture gradients.

The failure of gas refrigeration to recover temperture quickly or to freeze down as quickly as compressor bassed fridges.

Gas is certainly viable in a stationary situation, but the more mobile and compact things need to be the less viable it is.


cheers

I have to agree re gas problems. Fine for cooking but..........
Besides, Rusty already has 12v fridges etc.

With the advanced solar technology and improving panel economy, solar is the way to go. Maybe supplemented by a small gennie for those occasions of overcast days.

Olcoolone.

Careful how you say ignore. Facts are facts.
Camper trailer, 100a battery, 60 litre Waeco set on 3, 1 led strip lighting for inside, 1 fluro for outside, no dc to dc charger.
3 years ago camped at El Questro for 4 night. Just past the 3 rd day I tickled the battery by hooking the trailer back to the car.
Fraser Island this year, same set up, cooler temps tickled the battery on the 4th day.
In my opinion, people go overboard in what they are carrying.
It is nice to have luxuries but do you need all of them?

Have a good day.

Cheers

Greg

Richard, with a stated total battery capacity of 600 ampere-hours I can only wonder what you charge them with! As John has said above, storage capacity is of secondary importance if you don't have sufficient input.

And I would have thought that you would know the difference between amps and ampere-hours.

Alan, I run just short of 500A/H of Crank, Hybrid and AGM in my truck at all times (1x100 and 1x110 Hybrid under the bonnet and 2 x 140 AGM’s in the rear Pod). All are easily maintained by the standard vehicle system using appropriate DC-Dc chargers. In my case it’s a Redarc BCDC 12/40 under the bonnet and the Redarc BMS system in the rear pod. The AGM’s are supplemented by 330W of Solar Panel at times the vehicle is stationary (fitted this May).

I’d envisage the only times of real charging stress would be when the batteries have been excessively discharged, something I always try and avoid through by being proactive with the fridge/freezer, solar and or the need to run the vehicle for an hour or two. With the newly fitted solar, I very rarely have this problem. I’ve found with the right equipment, a few hours of normal vehicle use will usually top up the big AGM’s from as low as 70%. Crankers and an under bonnet Aux are generally at caopacity most of the time and generally are removed from any loop used for camping accessories/fridges and the like (or should be to my way of thinking). Therefore it’s only the 2 AGM’s or three in Richards case that will be requiring extra attention after the first few minutes of vehicle operation.

Standard vehicle systems will adequately cover these power situations in most cases providing you set up smartly and make the right choices in the first instance. I know I put a lot of thought and time into my power needs which has resulted in a system that meets my needs and has been entirely self maintained by the vehicle alternator and solar to this point in time.

In Richards case I wouldn’t mind putting money on there being appropriate DC-DC chargers near all of his batteries and suitable wiring to support them. You may never need 500 or 600 A/H but by god it’s nice to have should the need arise.

I always try & use the 7P principle always (Prior Planning and preparation prevent piss poor performance.)

Cheers Mick

Yes Mick, but Rusty is not running a mega-truck with walk-in fridges etc. Rather than lugging around huge battery banks with the associated weight and capital cost I would suggest that he would be better off following the advice in John's "Electricity for Camping" blog.

Rusty is talking about camping for 5 days or more and is using solar panels with gennie support. There is little point in having massive storage with inadequate charging provision. He would do better by investing in extra solar panels. By all means incorporate MPPT and DC-DC charging but that was not the original question.

And it's not "A/H" (Amps per hour) it is Ah (Ampere-hours), the instantaneous current multiplied by the number of hours.

Yes Allen I have 600amps of battery capacity, When i fill my fuel tank I know it holds 290lts of diesel but for some reason I can only use 280Lts..... now my batterys I know if they were flat I would have to refill them with 600amps...... my batteries far much worse than the 10Lts I lose in capacity in my fuel tank.... I can only run them down to 30% capacity before shortening their lives making my 600amps really only 420amps of usable power....... 360amps capacity in the 4x4 relates to only 252 usable amps..... so I know if I use 1 amp per hour I'll be able to do it for 600 hours, and if I use 2 amps per hour then I'll be able to do it for 300 hours.

The 4 reasons behind having big battery power is ....
1) Because I can.
2) The area where they are mounted is wasted space.
3) If I have to do a big winch I am not trying to draw 400amps from my starter battery and over cook the alternator with it trying to keep up.... alternators don't have a 100% duty cycle and it's a good way to destroy a $1000 alternator.
4) If I do destroy an alternator I know I have sufficient power to drive for 5-8 hours in the dark still using all lights and other bits and pieces.

Working on some peoples theories regarding overkill my thoughts are.....
1) Why buy a 19 foot caravan when you only need a 15 footer.
2) Why buy a turbo diesel when a non turbo diesel will still get you there.
3) Why buy a 4x4 up to 10 years old when a 40 year old one will do the same.
4) Why fit 285 wide tyres when you can still drive around on 245's.
5) Why have a fridge in your 4x4 when you don't need to drink cold water or you can stop at the shops.
6) Why fit M/T tyres when your not going to drive in the mud.
7) Why put driving lights on your 4x4 when you don't drive at night.
8) Why put a winch on when you're never going to go of the bitumen or use 4wd low.
9) Why put a bull bar on when you only drive around the city or during daylight hours.
10) Why fit a fishing rod holder permanently when you only use it 1 week of the year.
11) Why have a 4x4 as an everyday run around when you only tow your caravan or travel 2 weeks of the year.
12) Why have your UHF radio's microphone hanging from the rear view mirror.
13) Why buy a dual cab or four seater vehicle when there are only two of you's.
14) ........
15) ........

Why because you can!

And Allen.... when I typed my original post I thought about putting amphours in but I got lazy and thought everyone will know what I mean...... after posting I then thought someone with too much time on their hands and nothing better to winge about will pull me up on it and tell me I'm wrong..... looks like I was right.... :) (:- (((H)))



And Mick congrats to you and Vicky.

And Mick..... don't you forget......

"And it's not "A/H" (Amps per hour) it is Ah (Ampere-hours), the instantaneous current multiplied by the number of hours."

There is no room for mistakes and you will be frowned upon...

"Instantaneous current"..... didn't know you could get current that you had to wait for.... learn something new every day!

Thanks Al. Just as I've said below in the response to Rusty. I think we've hijacked this thread enough gents.

Rusty I hope you've gleaned suitable info. Johns Blog is a good place to start.

Cheers Mick

Why indeed Olcoolone, why indeed!

Those of us with electrical expertise often need to explain matters to some with less knowledge or understanding. We frequently need to emphasise the need for adequate cable sizing to avoid voltage drop and in so doing find it necessary to use terms such as Amps, Volts, Watts, maybe even Ohms. If we consistently ascribe the wrong terms (Amps instead of ampere-hours) it confuses the issue. First you may say that a particular battery is rated at "110 amps" then say that it has the ability to supply "600 amps CCA". Confusing to the inexperienced.

It really is desirable to understand and use the correct terms.

"Instantaneous current" is the current reading on the ammeter at the moment you observe it as compared to a current value averaged over a period. Your derision does you no credit.

Thanks Gents. You are offering no further value to this thread. Please take anything further off line.

The Modsquad