dc to dc amp issues

[rickyb9999]

Hi all,
I own a Nissan Navara D40 ST 2013 model. I recently purchased an Arkpak and the Arkpak dc to dc charger to go with it. To save re typing my problem i will cut and paste what i wrote to Ark.

This is what i wrote to them;

Hi i own a new Nissan Navara D40 Auto 2013. The user manual states the two dc sockets located in the veh, are 120w, however are only fused at 10amp. After doing some research i now realise to charge the Arkpak using the dc to dc charger the 12volt socket in the car needs to be rated at 120w and fused at 15amp. How the hell do i fix this? I have an Arkpak in the back of my ute, which cannot be charged off either dc socket using the dc to dc charger. Yes I have tested it and no it doesn't work.
.
At the moment i can charge the Arkpak via the 240v mains and solar. These methods work wonderfully, however i would like to leave the Arkpak it in the car on a permanent basis. Ideas or solutions pls. Thanks Richard.
.
Their response to this was this;

Hi Richard

Thanks for contacting us and asking such a great question, your first problem is an easy fix you pull out your current 10 amp fuse and replace it with a 15amp fuse this will fix that problem.

your 2nd problem is that your nissan navara D40 2013 modle runs on a VVA other wise know as a Variable Voltage Alternator, this means for your cig socket to work correctly your alternator must be running the problem with VVA is they shut down of approx 5 to 7 mins and then let the battery run the car and only come back on once the voltage drops to a preset level. to over come this problem and have your alternator runing all the time you must drive around with your parker lights on or your air con on this load on the battery forces the VVA to run all the time as the battery is under load.

if you want more detailed information you are most welcome to call me.

Regards

Brett from Ark.
.
My question to all of you, does any one know how to fix the issue i have. Arks response is not clear. Advise or tips would be appreciated.,

Thanks Richard.

 

[Malicious]

Ok ohms law p=vi so 12v x 10a = 120w , so a 10a fuse is correct for safe use, run a dedicated cable direct to the main battery terminals both positive and negative for the arkpak this way the current draw will be noticed by the hall device on the negative cable, then if it's still not charging I'd be having the charger tested

 

[Tappet]

Ok but wouldn't the D.C. to D.C charger needs to see 13. something volts in the first place before it turns on. If the charger doesn't turn on, there is still no load and alt will not ramp up the voltage unless there is load there, Lights on and aircond will probably do it but not a good way to go about it. I guess you could turn the lights and aircond on just to give a bit load which the alternator should detect then up the voltage. Once the charger does turn on the load will be there and aircond and lights could be turned off.

Do not put a 15Amp fuse in place of the 10. cars have been burnt to the ground replacing fuses with higher rating ones. Some of the wiring as is looks scarey thin.

The best bet would be go straight to the Battery (fused) to a lighter plug where it would be most convienient. Wire in a relay to power up the lighter plug outlet from an ignition and Acc. on power source to pull in the contacts on the relay.

There is a mod you can do to these type of alternators where it will keep the voltage high enough to activate/ turn on the DC-DC. charger. It's a simple mod just cuting the right wire or something. Try a search but some one may pop up who knows

If you run a fridge consider running the fridge off your cars electrical system while under way. That way the charger will charge the Ark Pack faster.

I had kind of a reverse problem with my DC-DC charger, the voltage in the battery after shut down was still just enough to turn on the charger, the charger would turn on, voltage would drop, charger off, voltage came back up and turn back on again and so on...Got around it by wiring in a relay between the charger and battery as I just described.

 

[oldmate45]

Have a look at this thread
http://www.navara.asia/showthread.php?p=297060#post297060
It will let you know how to achieve a constant 14V
Theres a couple of other threads out there as well.

Cheers
Jas

 

[Old.Tony]

^ Everyone up there is correct, even the guy from Ark is mostly right.

12volts times 10A fuse = 120 watts. As Tappet says, do NOT put a 15A fuse in - it's not needed, and is heading to a dangerous place.

It's the variable alternator - Malicious is going to be producing a device that overcomes this problem in the near future, so hang about and watch what happens!

I very strongly agree with the proposal to run separate cables. You MUST put a decent fuse - 40A should do - then run a heavy cable, like 8Ga (21 square mm) all the way to the tub. Use two wires - don't rely on the chassis/tub ground. Do it clean, do it right, do it once and not have problems.

 

[glc]

. Thanks for contacting us and asking such a great question, your first problem is an easy fix you pull out your current 10 amp fuse and replace it with a 15amp fuse this will fix that problem.

Haha! Cowboys...

 

[rickyb9999]

So let me clarify, run two leads from the battery one connected to positive and the other to negative to the rear of the tub using heavy duty cable, making sure a 40a fuse is attached to the positive cable. Inside the tub attach the two cables to a 12v socket and away you go? Correct me if im wrong, not technically minded when it comes to this stuff, still learning.

Some one mentioned a relay, where does this come into the senario?

 

[Malicious]

So let me clarify, run two leads from the battery one connected to positive and the other to negative to the rear of the tub using heavy duty cable, making sure a 40a fuse is attached to the positive cable. Inside the tub attach the two cables to a 12v socket and away you go? Correct me if im wrong, not technically minded when it comes to this stuff, still learning.

Yep that's right, also jaycar has some cable fit for the job , http://m.jaycar.com.au/m_productView.asp?ID=WH3063

Be lazy like me do it properly once.

The relay is used to isolate the DC charger due to surface charge increasing in the main battery, the charger will cut in main batt voltage drop charger cuts out , process goes over and over due to the hysteresis of the voltage cut out circuit not being wide enough,
Try the direct cable first
Also run it inside some split tubing

 

[rickyb9999]

Cheers guys.

 

[Tappet]

So let me clarify, run two leads from the battery one connected to positive and the other to negative to the rear of the tub using heavy duty cable, making sure a 40a fuse is attached to the positive cable. Inside the tub attach the two cables to a 12v socket and away you go? Correct me if im wrong, not technically minded when it comes to this stuff, still learning.

Some one mentioned a relay, where does this come into the senario?

Yep your got it right. Make sure the fuse is right at the Battery end, close.
Heavy duty sheathed cable is the go running it along the top of the chassis rail using some big fat cable ties. There should be a a little oval plastic bung in the front wall of the tub and you can bring the cable up thru there.

A relay will more than likely not be necessary it will still work fine without it but in some situations it could be handy. If you use a relay you could situate it anywhere along the positive wire going to the tub. It just means it will switch on the the outlet in the the tub only when the the engine is running or the key in the Acc. position.

There simple enough to wire up. Power from the Battery positive wire to one side of the switch in the relay, positive wire going to the tub on the other side of the switch. The switch in the relay is activated (turned on) by power from any ignition/ Acc. on source.

 

[rickyb9999]

Thanks all i have a better understanding.

 

[Malicious]

Just remember if in doubt on anything ask questions, the only stupid question is the one you don't ask