Second battery for plugging stuff in?

[Ursula]

Never done any car electrical before...
And very new to the world of the delica.
But I'm mech minded and I have a good idea of how it could be done in theory...
Our old car died, and one of the things we scooped from it before selling it for scrap was the battery. Bought new, late last year. We were using a cheap inverter, that plugged into the lighter socket to run things like a laptop, kettle... stuff like that. but we had to be driving as to not drain the battery too much.
What i want to do is have the secondary battery charge from the alternator while doing long drives, and have the inverter run solely off of that. That'll leave the original battery alone, also being charged from the alternator.
Does this make sense? Is this done? What the easiest way to do this?
Done a quick search of the forums here, but no luck.
I'm new here so maybe this has been discussed, in which case i'm sorry and could someone direct me to the right thread to read?
Thanks so much.

[Firesong]

Easiest way is to goto princess auto and buy a battery isolator.
You can get them anywhere like can tire in the rv section but
Princess auto has better pricing.

Accessory battery connects to ground, positive to isolator
then isolator to the other battery. The extra terminal , you
attach a wire which goes to any connection that is only on
when the key is turned in the ignition.

What this does is allows the battery to be connected to
the system when the vehicle is running. When the key
is turned off it is separated from draining the other battery.

What I did in my VW westie is this exact thing. Then I ran
a little fuse box (from princess auto - 10$ish) to some place
where I could attach other things to it easily. Fridge, cooler,
propane furnace, etc etc you get the idea.

Only thing to remember is that a normal battery from a car
isn't the best battery to use for this. It isn't made to be
drained of power to the bottom. Shortens the life.
But if that isn't a concern no worries. Once it's done replace
it with a marine battery or some other accessory battery.

It's a good idea, especially if you like to use it for camping
etc.

Firesong

[jessef]

National Luna smart battery isolator/charger all-in-one.

It's the best thing since sliced bread for running a main and an aux battery.

Google it or search for it here on the forum.

[Ursula]

Thanks! your tips and info will certainly come in handy!
Unfortunately, no princess auto. Back when i lived in Winnipeg it was my main source for cheapo welding stuff.
So Canadian tire it is. all the chepo quality with out the cheapo prices.
Battery isolator!!! I knew there must be a word for a thing that does that. and a quick google search brought up tonnes of specs and tutorials.
Thanks so much!
the National Luna smart battery isolator/charger seems amazing, but i kinda prefer DIYing things... maybe if i fail and get frustrated. where are these available?

we just picked up our new deli today, and i've been having too much fun just driving it around to think about mods. but this'll be the first one, and i'll document it for the site.
tomorrow i drive the malahat. Hit up the can tire. and wait till the weekend.

[DeliTan]

Hi Ursula and welcome;

What you want to do is exactly what I needed.

Just to add a little confusion...

There are at least 2 ways to "isolate" your batteries; the easiest and almost cheapest is to buy a simple "battery isolator" from crappy tire or wherever. This is a block of finned metal with 3 lugs on it as described above. Inside it has 2 diodes (one way valves) to isolate the batteries. The down side of these is that there is a voltage drop and your batteries won't get a full charge unless you make adjustments to your regulator.

The other, more complex system uses solenoids (relays) to direct the charge to the batteries without a voltage drop. This is expensive if you buy the "automatic" system.

As a career electron pusher and a DIYer I decided on the second system's technology but wanted it to be a manually controlled.

You can see what I have in my photo album if you wish.

Also, if you haven't heard yet, Having (and especially charging) a standard lead acid battery inside the passenger area of the vehicle is a "Bad Thing". There is lots of discussion on here about peoples choices in this regard. Suffice it to say you want a "sealed battery".

Good Luck

john

What i want to do is have the secondary battery charge from the alternator while doing long drives, and have the inverter run solely off of that. That'll leave the original battery alone, also being charged from the alternator.
Does this make sense? Is this done? What the easiest way to do this?

[sfd_656]

I am gaining confidence now with more research and think I may be able to tackle this on my own. Some of the forseable problems and some part options that I would appriciate any input on as i am sure i am missing at least one thing...

Is the stock alternator generally able to handle charging two batteries?

I understand that for wireing bigger is better what size should i go with between the 2 batteries?

Is it possible to fit a 2nd battery under the hood on an l400 I cant see it happening unless i go small but would rather not?

Wireing through the fire wall i have not had a thurough look but when i had a glance today i did not really spot any easy access to the cabin?

Has anyone ever done or thought of a system that was contained and easily removable (similar to the national luna ppp) just thinking that this might be handy when "camping" but would prefer to keep it cheaper. Could this be done fairly simply by using an anderson plug in the wiring to connect the two batteries?

Also the inteligent solenoid (listed @$140) national luna sells seems like it may be the fool proof way of protecting the main battery. With the bluesea solenoid part #bss9012($159) is the main battery protected from drainage?

Combining the inteligent solenoid with the national luna dual batery controller($95) will allow you to jumpstart off both batteries could this basically be done with just a simple switch?

At this point i am kind of sold on the national luna but, this has a lot to do with reading their opinions on the matter and not on actual user input, what are your thoughts on something like this kit which seems to include everything short of the battery... http://www.equipt1.com/companies/Batter ... attery-kit

Thanks for any opinions and ideas, I will also post this in the fourm as more minds can be a good thing.