ArkPak

Hi all,
I would like to buy one for my camper trailer but I have a few questions regarding charging of the AGM battery.

http://www.arkcorp.com.au/p/3231/arkpak-12v240v-battery-box .

If I charge via the provided AC socket or the $99 DC 12v car charger its protected by the smart charger however if I charge via solar or the anderson plug its not utilising the smart charger.

What do I need if anything to ensure I dont overcharge?? and will the same device work for both solar and the anderson plug from the car??

Im a little worried ill spend about $500 on this all in one super cool bit of kit to find out I need to buy additional equipment to charge it while out camping.

and if anyone can answer it, if they put a smart charger in for AC power why couldnt they just run the solar and anderson plug through the same charger??

Hope that makes sense

Thanks

Aaron

Welcome to the forum, Aaron.

Solar is a different beast to deal with. 12V solar panels unloaded (nothing connected to them) will put out 20V easily. If you're going solar, you need something with a circuit that will handle this higher voltage (higher than expected voltages can ruin semiconductors). Because of this, solar panels should always be used with solar-specific regulators. Some panels come with regulators built in. Neither is safe to use directly on a battery without some attention to the battery's voltage - that's what the smart charger is all about. It is perfectly safe to plug the solar panel into the input side of an inverter and drive the 240V charging circuit - but you're buying an inverter instead of a solar regulator (some regulators contain charger circuits, plug that into the Anderson plug).

Overcharging a lead acid battery spells doom for it as the electrlyte boils away. You're quite right to be concerned about it.

Directly charging it from the car's battery (via the Anderson plug and not the DC-DC charger) will NEVER overcharge it but it will always undercharge it.

An idea that might appeal: send your 12V to the tub from the engine using decent cables (eg 8Ga). Connect to a relay up front so that the line is disengaged when the engine is off - find an ignition-on source in the box behind the battery, then attach that to pin 85 of a single-pole relay. Pin 86 to earth, 30 to the battery via a 40A fuse, 87 connects to the cable to the rear. In the back, connect the 8Ga cable to pins 85 and 87 of a double-pole relay. Pin 86 goes to earth. Pin 30 goes to the new inverter. Pin 87a goes to the solar panel. Connect all the negative (earth) cables together. Result: when the ignition is on, the solar panel circuit is disconnected. The new inverter (needs to be 150W or so) charges the Ark pack.

Thanks for the reply Tony, its a bit late at night for me to absorb all that but I will draw it all out tomorrow and try to get my head around it I hate electricity and all things that interconnect the things that make it work but its time to learn..

Thanks again for your help

Aaron

p.s Bunnings sell them cheapest at $399

bgorm6 said:

p.s Bunnings sell them cheapest at $399

Click to expand...

Thanks for that... spoke to Rays they are happy to price beat, mabe a $1 less.

Any ideas on the best place to get discount batteries?? do battery recyclers exist??

Aussie batteries and solar

I consider the ArkPak style of stuff not much chop. About the only advantage is the compactness.

For an all singing & dancing alternative; your can buy the following items;
1) c-tek D250S, takes feed from alternator or solar panels and smart chages wet & AGM batteries,

2) Apporpriate c-tek mains charger(C/20 is better life, but C/10 max rate). they come with a tail you fit to battery terminals and leave, then just plug charger into tail when needed.

3) inverter to match needs, whether economical MSW or Full sine wave. Somrthing like a 150W or 300watt at max. If you really need bigger than that, then you need to look at a 24V system or a generator.

4) a basic multimeter and log book to record voltages before and after.

5)) Optional 12V cut off device to prevent batter running too low and shortening life.

I have three anderson plug tails bolted to each batery and I've knocked up/am knocking up various fan out board with fuses to cater for needs. I started with bannana plugs for an early lighting system and radio power, and am moving onto a cigarette & merit socket board.

Batteries are fine and simple electronics. Just make sure you use fuses in the positive wire otherwise sparking can be very danagerous.

if you go to a battery factory like supercharge or century you can buy seconds. ive been using them for over 20 years in my cars and boats and have never had an issue with them.

I have a fair bit of experience with this as i own one.

I'll keep it simple as possible.

First things first, the Arkpak will cost you around $400-450. You will need a battery perferably an AGM battery as it is sealed and the safest, which will cost you around $300 for a 130ah. These can be purchased off ebay. Ps 130ah is the max you can place in the Arkpak.

I own a 60lt techni ice fridge which uses about 1.5amps per hour, so get about 2-3 days out of the Arkpak depending on temp set, without charging it.

If you are going to buy solar panels to charge the unit, i would recommend min 120watt. This will charge the unit around 6amps per hr. Keep in mind in winter you only get around 4 hrs of solid sun, so it wont fully charge the unit. Most solar panel kits are plug and play so to speak and come with a regulator, which prevents the Arkpak from over charging. All you do is plug the solar panel into the unit via the anderson plug and face the solar panels towards the sun and charging begins. Solar panels on ebay are around $180 for a complete kit. Ps make sure isolator on the Arkpak is in the on position, when solar panels are plugged in and charging. If you are going to purchase solar panels make sure its a MPPT regulator not a PWM. MPPT are 20-30 more effecient than the PWM regulators and will charge the Arkpak slightly faster.

When charging via the AC charger make sure Arkpak is in the off postion as it uses the smart charger to regulate the charge cycle.

I found the best way to charge the unit was to set up a dual battery system in the veh. They cost around $300-600 installed depending on brand. It plugs into the Arkpak via the anderson plug and charges from memory around 11+ amps per hour, when car is running. The installers will put a anderson connection on the bumper of your veh, which can then be connected up to the Arkpak in your camper. Ps make sure isolator is in the on position. PPS dont worry about over charging, the dual battery system, will prevent this from happening.

When i get to a camp site and take Arkpak out of veh, i then plug solar panels into it.

If you cant afford a dual battery system, you can put/mount your solar panels on the roof of your veh/camper and charge the Arkpak that way, however the panels will not always be directly in line with the sun, so charge time / amount will vary.

Be careful when charging via the 12v charger, which plugs into you cigarette lighter. Some vehs have smart alternators and which prevent the Arkpak from charging via this method. You can over come this, but thats another story.

Finally, do not let the battery fall below 20% as this can damage the battery. Some people perfer 50%.

That raises an interesting point. If charging by AC charger you have to have it in the off position - this rather heavily implies that your fridge has to be disconnected from the battery.

This isn't the end of the world - it's in fact how I charge my aux battery in my tub - but that's because I'm making use of a feature of my fridge. When my Engel 60L detects 240V, it will switch over to that whether 12V is present or not. For the Arkpak to be used in a similar situation (let's say you're topping the battery up with a generator) your fridge needs to be plugged in to that genny too, and needs to auto-switch.

As for the battery levels - that's good advice. Most of the current deep cycle batteries can tolerate discharge to 20%, but they start allowing sulphate crystals to form below 50%. This isn't as much of an issue in an AGM as the glass doesn't allow the formed crystal to move, so it will more often than not break back down when the battery is recharged. Spiral wound AGMs can be discharged to 0% without killing them (mine - an Optima D31A - has done this about 4 times so far). 50% is the mark where slow rates of sulphation become a rush, and this raises an exceptionally important point that you really need to consider when thinking about what you're taking with you.

If you have a 100Ah battery and want to keep it in top condition, you're going to invert the incoming power to your tub, use that Arkpak smart charger with the fridge drawing 240V so that your battery arrives at the campsite at 100% charge. If you're looking after it, you're going to turn off everything electrical once the battery reaches 50% That's 50Ah used.

So with just 50Ah of capacity available, what can you run? A Waeco fridge with a BD35 Danfoss compressor will happily draw 3.5-4A of power. Overnight, when it's not being opened much in cooler air, it won't cycle a lot at all, maybe 10% in winter, and 30% in summer. 30% of 12 hours @ 4A/hour is still 14Ah-ish (mental arithmetic). Great, so the fridge needs 15Ah when the sun isn't shining - it will need more during the day, especially since people are awake and opening it! Say for a 24-hour period it will use roughly 40Ah. That leaves you 10Ah spare (if you're not charging until the car is running again) for lights, phone charging ... doesn't seem like a lot any more! You'll need to kick the car over every day and let it run for what, 50Ah charged at 6A/hr = about 8 hours, so once you're camping, maybe you want a higher-rate charging device to look after it.

These sums do look messy and depressing, but the answer is in overkill. Our caravan, for instance, has a 100Ah AGM battery. The only thing it's used for is lighting, water and toilet pumps. With all the lights on we're drawing about 2.5Ah, and because you use the pumps so infrequently, don't worry about them. That gives us (say) 4 hours of lighting (6pm to 10pm) = 10Ah per day. I've put a 130W solar panel on the roof that can replace that power in under 2 hours. Because it's a mono panel, it's quite shade tolerant and still makes good power underneath trees or on cloudy days.

And that's how you do it. Budget your power first, look at what you need to use, make sure you have that storage capacity and then overkill the charging capacity. Don't run solar to an inverter to drive the inbuilt smart charger. In winter you simply don't get 8 hours of solar-useful sunlight a day! If you're going solar, make sure your battery can handle a good load, hook up the solar regulator to the Anderson plug and dump the power in that way.

Hi guys,

I also have an ArkPak power box and stumbled upon this thread while searching for info on Anderson plug setups to charge this unit and I am hoping some of you might be able to tell me if I am on the right track or not with my idea

At this stage we only use the Arkpak on random days at the beach, or a weekend away type thing, to power a portable fridge or a few appliances, as we are just with the basics in the Navara, no caravan for us, lol. So it's not really an issue to let it sit at home and slowly recharge via the 240v charger, but I am now thinking of running an Anderson plug from the battery into the cab of the ute, (I have fixed the mounting brackets for the Arkpak on the floor behind drivers seat), so I can connect it up for the trip home and try to get the bulk of juice back into the Arkpak battery quicker, then just put it on the 240v for the final top up.

So my question is, for this scenario, am I ok just running the Anderson plug straight from the battery with a fuse in the positive line, or will I need to put an electronic isolator in the system as they do with dual battery set ups? Also what size/gauge cabling should I use for this?

Cheers,
Leon.

You'd need an isolator, or the auxiliary battery will try dumping power to the starter when you turn the key.

A cheap alternative is to put a 150A relay (eg this one, maybe you can find a cheaper one) in to keep the power off until the accessories are online. Easy to do: pin 85 to any accessory-live feed in the IPDM/ER (the black box behind the battery). Oin 86 goes to battery negative (or any chassis/body connection). Pin 30 to a fuse of (say) 40A which then goes to the battery positive. Pin 87 goes to the cable run to the rear which should have a fuse installed just before the battery.

The cable to the rear is very important. If it's not a heavy cable, it will heat up under loads and it will also lose voltage. You might have 14.2V up at the battery, but that may diminish to 13.5V or less at the rear. This will reduce the charge rate of the aux battery.

Hey Old.Tony, thanks a bunch for the reply and my apologies for the late thanks, I have been on night shifts the last week, so it has been nothing but a routine of work, then sleep, lol.

I have found the BushPower VSR isolator on sale for $38, so think I will grab one of those and then find out what the largest cable you fit into a 50amp Anderson plug is and go with that

Thanks again.

I'm using 8Ga cable on my 50A Anderson plugs and they are a very tight fit. They are easier to assemble if you pre-wick the ends of the cable, shape them down with a file if needed, then insert into a red-hot plug (I solder them in with a pencil blow torch, makes very quick work of it).

While 8Ga cable is larger than 400A jumper cable from KMart etc (shows you how dangerous some of that stuff can be) it really can only handle 56A (rated, continuous). I ran two lots - so there's 4 of these suckers - along the length of my car.