Charging Auxilliary Batteries

Freezer,
Lash out and buy a decent Solar panel with a reliable, easy to use solar regulator that will be charging a large AGM Deep Cycle Aux battery and you won't have any problems.

Derek if you can put back 45 amps into an auxilliary battery in 2 to 3 hours you are a miracle child. I dont think you know much about batteries or auxilliary battery systems.

Engel will not take more knocks and as a matter of fact the swing motor bangs crashes and fails.

Quote: "Engel will not take more knocks and as a matter of fact the swing motor bangs crashes and fails."

What facts do you base this spurious statement on???

I agree with Shaker above here,

not many posts bout Engels failing on here, except once they are 20yrs old or so, plenty about Waeco fridges stopping, turbo system malfunctions, dodgy switches etc. the list goes on.

Sure the Engel costs a bit more, but show me a bloke who has one and says it wasnt worth the extra dough? Quality costs a bit more in anything.

The Waecos are reasonable and have their place in our fourbie world, but if your gonna get serious and subject a fridge to lots of off road vibes bumps etc the Engel takes it best. FACT. (search on here for fridge problems and it soon becomes clear that $200 extra is well spent)

I do await to hear how the swing motor bangs crashes and fails though????????

Rgds

Ron

Jeff,
after reading your post I understand your dogs choice, L0L
and I also wish both him and his customers total satisfaction.

The cable size we used is B&S 8mm, should be better than B&S 6mm shouldnt it?
Cheers
Freezer.

Hi Freezer, confusingly, the smaller the B&S number, the thicker the cable sizes.

B&S 8 = 7.9mm2 while B&S 6 is 13.5mm2, the exact size will vary slightly between manufactures.

Do a google search for B&S and don’t put spaces between the B&S. You can also search using AWG ( American Wire Standard ) as these two measuring codes are identical.

Wire sizing in Australia is a bit stuffed as there is no mandatory code set for automotive cable sizing like there is for AC domestic cable.

By the way, what type of batteries are you using.

Cheers

Hi again Freezer, I have just looked at your post down below this and see you are running wet cell batteries, as posted, to get better charging results and to reduce the charging time you would be better set up if you fitted at least B&S 6 cable and invested in a larger alternator.

Works out a lot cheaper than going solar, now before all the solar enthusiast come a running, I personally prefer solar but for most the cost is just not warranted.

Cheers

Afternoon Boo
Thanks for your reply, i definately agree with the conveinience and hassle free, of a 3 way. No worrying about flatening batteries. I am just a bit wary as from the posts i have read on this site, a lot of people are saying that they can struggle a fair bit in hot weather. I live in Qld.
My main problem is i took father in laws advice in getting this battery icsolator set up, and given it is a fair setup, but really only good if your touring, and on the move every couple of days. This is not our case at the moment.( Cant really drag the camper trailer around every day to charge batteries once set up for two weeks on morton or fraser.) So i my only other real option if getting a compressor fridge is to get a 80watt solar panel. $800 later. Bit of a kick in the guts after spending money on alternator system.
I wonder if a Gen set and batery charger would work?

Cheers
Freezer

Gen set and 3 stage charger will certainly work Freezer. The 3 stage charger is also great for a good charge when you have access to 240V.

Downside? Some National Parks and camp grounds don't permit gennies. Also, even when permitted, you need to consider campground etiquette if near others.

If I understand your set up, you don't have a DC in the vehicle. If you add one, it will charge every time you drive. Make up an extension cord to run to the fridge. This will give you another power alternative if the CT batteries are run down, but you have been for a good drive during the day.

This is how I am set up. I have two DCs (AGMs) in the CT and one DC in the vehicle. I have set up so I can run anything from any battery. I am currently making provision so I can move one of the CT batteries to the vehicle if I want for a particular trip and have two in the vehicle and one in the CT. Flexibility is important in my view.

I actually prefer the fridge in the vehicle. Cold beer and lunch available no matter where you are. And if you drive to town for some shopping, you have the fridge available for the cold stuff. Also your main power drawer (fridge) is near the most efficient charger (alternator) which gives free charging every time you run the vehicle.

But we all have different views and sometimes circumstances dictate a set up. You can only play the cards you are dealt.

From our experiance witrh the Chescold 50lt, you wouldnt have too many problems with the temp not getting down enough. We were using ours over xmas when the temp was around 38 - 40 and we had to turn it down as far as we could so the contents wouldnt freeze. We find on gas (or 240v) its extremely effective cooling even in the hottest conditions. On 12v it will maintain temp but doesnt drop the temp overly well.
Personaly from our experiance I cant fault the Chescold unit even in very hot conditions.

The way we use our sytem..
We leave the 12v Downunder in the vehicle running off the dual battery sustem which recharges when and if we go for a drive, if we dont do any driving I leave the car connected to the larger batteries in the camper which runs the fridge/freezer (Downunder) and camp lights. The Downunder in the back of the car running on 12v is used as a freezer that way we arent opening it more than once or twice a day to move stuff into the other fridge unit running on gas we set up beside the kitchen at the camper.(which is the 3 way Chescold unit). After about 8 - 9 days we have the option then of moving anything thats left in the freezer into the Chescold to minimise the remaining battery life just for lighting which could if needeed run the lights for another 4 or 5 days without charging and still have things cold and frozen in the Chescold.

Hope that helps..
If you need any info on what lights etc. I'll give you my email address and give you a more detailed run down and some picies..

Mike
They are filler cap ones. Yeah i know the solarpanels are exy, thats why we didnt go down that track originally(although i really like the concept).
I went the alternator way on someone else knowledge and didnt look into the efficiency and practicality of it in our camping situation until after i got it. Dumb i know! But usually the father in law does know everything, maybe its been a big facsade all these years LOL

Brett - since they are wet cell DeepCycle, they will limit how fast you can charge them.

It would take at least 5 hours to charge them fully, but you are only taking out about 50% of the capacity. There's no point in upgrading your Alternator - the batteries won't be able to take more current.

Especially with such a long run of 8Ga - you should really upgrade to 4 Ga to keep the voltage drop down so there is enough volatge at the batteries to charge them.

Make sure you check the Alternator voltage at the front batteries when at fast idle - if it's less than 14.4 volts you will have very slow charging.

Mike

Hi Mike, while I agree with you on the cable up grade, Freezer would definitely benefit from an alternator up grade as well.

There are a number of problems that come with having a small capacity alternator and the first is that the vehicles engine revs are going to need to be around 2,000 rpm for him to get any where near 60 amps and as most alternators are rated at their maximum output not the continuos output then Freezers alternator is probably flat out producing 50 amps.

Because of the likely hood that the engine is not going to be at maximum rpms for the alternator to be able to put out 50 amps, the lower amps will be required to power quite a few things, particularly at night so Freezer will be very lucky to be getting 14 volts while trying to charge his batteries and running everything else, including his fridge.

A 100 amp alternator would be far better as it would be able to put out the amps needed at a lower engine rpm and more importantly, much higher volts.

G'Day Derek,

Well theres a thing, a man who owns a Waeco but admits Engel are better!

Question for you, can you put an AGM in as your aux battery when your main is still a wet? (wired through an isolator/charger of course)

Rgds

Ron

i am not an expert by any means when it comes to auto electrics, so this question may sound as dumb as dog S@#t, but is 8 B&S cable better than 6 B&S cable. I thought the higher the number the thicker the cable

Hi again Freezer, most cable in Australia does have the square area marked on it, not all though.

If you have an idea of the maximum current requirement of a given circuit.

If you know the maximum current you need, to reduce voltage drop and give the circuit a decent bit of safety, multiply the maximum current by 3 and then try to match the current required to a suitable cable size.

You can do a google search and get some handy cable comparison charts to help you workout what you need.

With cable that is going to be used for charging batteries, it is better to go to even larger sizes and in this case bigger is MUCH better.

Your 8 B&S is the minimum size that would be used to charge a battery in the vehicle but is to small to adequately charge a single battery in your trailer.

Cheers

Couple of points that may lighten the load.

If you have a good quality battery charger at home, if you charge the batteries up before you go for you shorter trips, your alternator will have no problem keeping them fully charged while you are getting to where you are going.

Next, again if you have a battery charger, take it with you and you may be able to extend the operating time of your batteries while you are away.

As for the Anderson Plugs, if they are SB50s then they have a continuos rating of 50 amps which is heaps big enough for your set up. There is no way you are ever likely to pull more than 50 amps even with two flat batteries and the fridge running.

Cheers.

I have a Chescold freezer we use as a fridge and works in all temps in NQ. Bought a 55w solar panel for $500 a regulator for $120 and 60 amp gel battery. Powers my fluoro lights and small LCD TV. Have had the solar panel for a year and returned last week from 7 month trip and battery never went flat once. The battery is only charged on the small caravan by the solar panel.

One more point and slightly of subject, I don’t know how long you leave your trailer between uses but if it’s anything more than a 3 or 4 weeks at a time, your batteries would benefit from having a maintenance charge on them during these non use periods.

Cheers

yeah i have them connected to a 10 amp charger, it does a boost charge to 80% capacity then Float charges until full, then maintains batterry as needed

Freezer

Hi Sand Man, in Freezer’s situation devices like that would actually take longer to recharge the batteries and remember, on top of charging two batteries, he still has a fridge to run.

For about the same expense, as suggested above, he would be far better off upgrading his cable and alternator.

They are only effectively time savers on small batteries up to about 70 amps and once you get over 100 amps they will NOT speed the charge up and they will take longer than a properly set up dual battery system will when running straight off the alternator.

drivesafe

I have become a little uninspired when it comes to my alternater setup, even if i do as you suggested with the upgrades in alternator and cable. I still question its effectiveness in keeping my battery bank topped for 2-4 week stays. If i was only staying in one place for a couple of days then moving on it would work well, but with a couple of littlies they would not enjoy it asmuch as i would. I am now thinking:
1. Get 3 way fridge, and run only lights,lcd screen, pump taking around 10-12amps per day. The alternater may handle this in a better time frame.Could even get a 20 watt solar panel to help or:

2.Get compressor fridge and charge battery bank (2 x 75Amphour wired parralel) from gen set. (not sure how long this would take if using 40-45 amp per day)