charging camper battery?

hi

I have just taken delivery of my new D40ST

I have a camper trailer with dual batterys. my previous tow vehicle was a prado.

My charging setup was simply a live feed with 8g cable running directly from the battery to the rear via an anderson plug.

speaking to a 4x4 store they have advised me that that type of system will not work with the navara.

I have a solar panel to feed the battery's when set up and just used the vehicle to run the fridge and top up the batterys whilst travelling. before the solar panel I used to run the prado for 30 mins every few days to top them up a bit.

Will this system still be suitable or will I need to purchase this expensive charger that the shop was trying to sell me.

In short will a direct feed with 8g cable from the battery to the rear via anderson plug be sufficent to charge the battery's?

thanks
Jason

That will be fine, but I would run it from the output of a RedArc solenoid or something similar so the car battery gets it's top up first.

+1 on the isolator.

I think the shop's objection is because the Navara's ECU looks at the battery and decides how much it needs to be charged and adjusts the regulator accordingly. Because a long length of electrical cable will have some voltage drop, checking a battery down on the other end will be inaccurate.

You COULD do it the way you've got it now and you'll get partly (read 70-75%) charged batteries rather than fully charged. You could avoid that by using a DC-DC charger (which is probably what the guy was trying to sell you) and that's not a bad solution - it's safer than the way I do it, for example: I use an inverter, and a 240V charger.

what output in amps is at the alternator?

I will be using 8G cable, from the vehicle battery to an aderson plug, then from the anderson plug the battery's are on the drawbar. max cable length 6m.

What sort of drop should I expect?
will larger cable help?

thanks

Current available at the alternator does depend on what else you have running and what the ECU is telling the alternator to put out.

8G cable isn't too bad. Over 6m the resistance is 0.012366Ohms so you won't lose a lot.

sorry for the novice questions.

But why would the battery only charge to 70% if the current isnt dropped much?

I usually charge my trailer battery before leaving home then plug it into the car via anderson plug.This runs of the second battery in the tub and is hooked up to a C-Tek 5 charger at home and is charged via a redarc solinoid on the road.

At camp 100w solar panel keeps it topped up or run the genny if needs more.

The state of charge is limited to what your car will provide. There's an excellent article written by Collyn Rivers on this page.

Basically it's to do with the voltage applied to the battery. Your starter battery is in the same boat. The reason for this is to prevent your battery from gassing - boiling away the electrolyte.

That's the reason why I use an inverter and a 240V charger - 100% charge, guaranteed.

looks like I might be getting a dc/dc charger for the road, I like the idea of having fully charged battery's

Dont know if the prado would have been any better/different in charging, Relative with a 120 series prado invested in inverter and not sure what else as the prado supposedly wasn,t up to the task of fully charging the camper batteries, So is a d40 any different

http://www.navara.asia/showthread.php?t=6647

Hi Jason, Check out the above thread. I did this mod about a year ago now and non problems whatsoever.

Regards

Foxy

D40 has 125+ amp alternator vs the 90A (typically) in a D22.

That doesn't make much of a difference. If it's a gel battery in the camper you don't want to charge it faster than about C/20 up to C/10 max. Flooded batteries about C/10 up to C/5 (warning: check the electrolyte often). AGMs can be charged at C/3 and for a 100Ah battery that's 30A.

The other problem (when considering charge rates) is that the alternators only put out these amounts of current when the ECU tells it to and when the engine is being flogged.