Monday, Nov 12, 2012 at 08:16
Hi Phil,
As Dennis says, using separate cables for fridge and battery charging is the way to go. There's a question hanging over your 6mm cable - Cable sizing is full of traps - some "6mm automotive" cable is actually 6mm in diameter, including the insulation. Often 6mm cable refers to cable with a cross sectional area of 6 square mm of copper. Sometimes we see 6 AWG or 6B&S cable incorrectly referred to as 6mm. (Cable details may be found
here.) Assuming that your cable has at least a 6 square mm copper cross section it should be fine, if it's 6B&S, better still.
I can't find any specs on the Cetek 11 charger, but assuming it's for mains charging, there should be no need to disconnect it when charging in other ways.
Fitting a 120W panel sounds good, though it depends on what loads you want it to handle. I think you will already be aware that a battery system isn't up to running a 3way fridge. If you are running a compressor fridge as
well as lights etc, you may find 120W of solar capacity barely adequate. (Depends of course on how long you want to be independent of other charging options and you storage capacity.) In any case I would aim for an MPPT type of solar controller.
Your "secondly.." I would use the heavier (6mm) cable to run from the tug to the battery. (Note that there MUST be a fuse in this line, close to the battery, to protect the wiring from the battery current in the event of a problem.) If funds permit, inserting a dc-dc charger in this line close to the battery would be a big advantage. Assuming that you have 100 Ah storage, a 20 amp one would be good, and if you have more storage, perhaps a bigger one. (We use a 30A dc-dc charger with 200 Ah.)
If you go this way, you will need to consider the capacity of your alternator as these chargers draw more current than they deliver. Then add in the current drawn by a 3way fridge and keeping the vehicle running and the alternator may start to stagger.
Worth bearing in mind dc-dc chargers such as the Cetek D250S that provides in one package a 20A charging current, plus an MPPT solar controller, plus handles the voltage sensitive switching to connect itself to the alternator when charging current is available.
If you haven't already been there, you may find
Electricity for Camping a useful read.
Cheers
John
| J and V
"Not everything that can be counted counts, and not everything that counts can be counted."
- Albert Einstein
Lifetime Member
My Profile My Blog Send Message |
AnswerID:
498374
Follow Up By: Dennis Ellery - Monday, Nov 12, 2012 at 11:06
Monday, Nov 12, 2012 at 11:06
Hi John,
Its not a Cetec - Phil is talking about a Setec battery charger/power supply used in Jayco caravans.
Their specs show that you can connect a DC charging source directly to the battery.
Regards Dennis
FollowupID:
774362
Follow Up By: Phil H6 - Monday, Nov 12, 2012 at 11:19
Monday, Nov 12, 2012 at 11:19
Thanks for all the info' John Val & Dennis. Just to put the picture a little clearer. My tug runs a 100ah alternator and maintains running voltage of 14.4 volts, so there's ample supply. My house battery is only 100ah. So I have decided to use a 10amp dc to dc running 6mm cable rated at 50amps. My solar panel is 120watt supplying ~9amps or so depending on conditions. And I will leave the original setec in place. When we
free camp we only use gas for the fridge. All our lights are "led's" which is a little saving. Our biggest drain is our laptops, and we generally recharge them while driving. So all things added up I think the picture looks pretty o/k.
Dennis do you have a link to the Setec specs that show it is o/k to connect a dc charging device direct to the battery? Or can you please tell me the wording used?
Thanks again. Phil.
FollowupID:
774363
Follow Up By: Dennis Ellery - Monday, Nov 12, 2012 at 11:34
Monday, Nov 12, 2012 at 11:34
Hi Phil,
I only have a hard copy, if you list your email address I will scan it into a PDF file and send it to you. Try Jayco - they are very helpfull and may send you their manual.
Regards Dennis
FollowupID:
774365
Follow Up By: Member - John and Val - Monday, Nov 12, 2012 at 11:57
Monday, Nov 12, 2012 at 11:57
My apologies to both of you - I seem to be prone to invalid assumptions! Still Setec and Cetek is good grounds for confusion! I'm always mindful too that there will often be 1000+ people looking over our shoulders when "talking" on this
forum, and one should aim not to lead them astray.
Your setup sounds fine Phil.
Cheers
John
| J and V
"Not everything that can be counted counts, and not everything that counts can be counted."
- Albert Einstein
Lifetime Member
My Profile My Blog Send Message |
FollowupID:
774366
Follow Up By: Phil H6 - Monday, Nov 12, 2012 at 16:53
Monday, Nov 12, 2012 at 16:53
Thanks Dennis. I just had a look at the Setec site, and sent them an e-mail enquiry so will be intereting to see what they say or offer.
E-mail is philmar1@westnet.com.au if you wouldn't mind sending me a copy Dennis.
Thank you.
FollowupID:
774377