Portable battery power box and charging

 Looking for some advice regarding a portable power battery box and best way of charging

I cant fit a dual battery system under the bonnet of my PK Ranger so it would be in the tray. So l thought it would be more user friendly to have a portable power battery box that can move with the fridge.

The research lve done is theres afew options on brands and they all do the same but charging is the main difference to some units which is were lm looking for info.

Currenty looking closely at the kickarse box and battery that has  a 120ah agm DC battery sold through australiandirect . This unit can also be bought with a 3 stage dcdc charger and wiring kit that can be connected to the car for charging or solar panels. I like the fact the battery can be charging while driving. It would live permanently in the ute with the fridge. If l was not to get the dcdc charger it would be charged via 240volt at home and the fridge and battery would not stay permanently in the ute due to the battery needing charging every 2/3 days..

Heres my main question on deep cycle batteries. Does the life of the battery suffer by being left maintaining on a charger for long periods when not being used ie 1 to 2 months.  Is it better for a DC battery to be discharged/charged on a regular basis and maintained by a dcdc charger in car.

Please set me straight on DC agm batterys and life expendancy and charging.

Thanks for reading

Paul 

 


davmor's picture

Posts: 248

Date Joined: 29/11/11

 Ive got a PK Ranger with

Thu, 2016-06-23 06:08

 Ive got a PK Ranger with second battery under the bonnet. A 60 ltr Waeco is permanently in the rear. On the roof is a 100 watt solar panel. All this adds up to cold beers no matter where you are. This setup is nearly 6 years old. I was told with the dual battery in constant use will shorten its life. Ive recently replaced the battery for the second time. So that equates to a battery life of 2.5 to 3 years. I dont understand electrics and took a punt on solar size but seems to do the job.If you want to go mobile, Primus have power pack that might be worth a look. When youve got it set up I am willing to help test the temperature of the beers.

Cheers David

Stevo81's picture

Posts: 1278

Date Joined: 16/04/12

 I have a similar setup to

Thu, 2016-06-23 06:55

 I have a similar setup to David. Aux battery under the bonnet to run the fridge which permanently lives in the back. 120w solar panel on the roof and a redarc DCDC charger. Alternator charges Aux battery when driving and solar takes over when vehicle is off. Works a treat. Fridge has been running 24/7 for Over 2 years now.

Are you sure you can't fit a Aux battery anywhere? Speak to ARB they make a few different mounting options. Leaving a quality 240v multistage charger connected to a battery won't harm the battery either.

edit- just Re-read your post. Dunno about leaving a charger on for two months. Might be better off dissconnecting the load and letting it sit then topping it up a day before using. 

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Swompa's picture

Posts: 3871

Date Joined: 14/10/12

 Good quality smart charger

Thu, 2016-06-23 07:22

 Good quality smart charger should be fine being plugged in for long periods. The Ark Pac's have 5 ah smart chargers built into the battery box and can keep the battery floating. I used to have one but binned it after drained and killed two batteries before I discovered the seriousness of a power leak somewhere within the unit. Ark Pac was new though a gift thus I never got a receipt. $400 worth of batteries down the drain...

 

Brother keeps his permanently plugged into the wall when not in use, 3 years later it is still going strong when he takes it out.

Posts: 812

Date Joined: 09/10/06

 Thanks for the replys. My

Thu, 2016-06-23 07:25

 Thanks for the replys. 

My rangers an auto so space is a problem. Geabox controller in the way. Not saying it cant be done but from all my research its best to go another option. 

Arbs price is outa this world for there system.

Can the DC batterys be left discharged for periods of time?

My fridge is an 80lt so thinking will need a big battery.

Posts: 790

Date Joined: 25/05/12

 I had an ark pack they are

Thu, 2016-06-23 09:05

 I had an ark pack they are hopeless, now I run a cteck charger to a battery in rear of work truck  easy to install only hard part is  just need a wire to run to the starter battery.

same as other guys said it runs of solar or of the alternator depends what's giving best current for charging at the time..only difference is you have to wire up your own sockets  for Engel and a voltage gauge also helps 

ranmar850's picture

Posts: 2702

Date Joined: 12/08/12

I have a couple of auxiliary boxes

Thu, 2016-06-23 08:19

 Had the first one made up by local auto sparky to charge from both solar and car. Made the second one myself, very easy if you have any tools. I couldn't see the point of fitting a permanently mounted second battery although I had plenty of space ( GU Patrol). If only for the reason that batteries don't last as long when mounted under the bonnet of a car suffering from constant heat and vibration--people don't seem to think about this. They are both deep cycle, 105a/h but a 120 would fit. I have two as I was running two separate solar setups and keeping them independant, one for camper and fridge, one for freezer.

photos.smugmug.com/Travel/Random-camping/i-JMTnPsB/0/XL/camper%20electrics%20018-XL.jpg

The oldest would now be 5 yo, still vg capacity. Only care taken has been to leave them on the Ctek 5 amp battery tender for a few times a year.  The unit in the above picture is simply based on the cheap battery boxes you can pick up anywhere. I have added 2 Merret plug sockets to supplement the cigarette lighter outlets. The solar regulator shown is a $95 cheapie from ebay which has been perfect. The other (original) box was made up with a Plasmtronics PL20, a $320 unit with far more functionality built in than you will ever need in this application.  if you look at the plugs, note the difference--they are paired so that you can only plug the solar and car charge into the right places. Permanently installed lead in car from starting battery with a self-resetting breaker and Redarc relay for charge on the go.

What is not shown on the pic is a mod I made later--I have a 50A Bushpower smart charger for when the sun won't play. First time I tried to use it on the external terminals, I blew the internal box  fuse as they are only 30A. So I added a 50A Anderson plug mounted on the side wired direct to the battery terminals and made up a lead to suit--now I can plug in direct without disturbing anything.

System is still evolving, and now I have decided to simplify matters by paralleling the two batteries and using a larger single array for the month-long permanent camp. I added a  short tail with a 50A Anderson plug from one of the batteries so it can plug into the Anderson inlet on the other one, which means I can use the big charger directly into one and charge both if required, or break them and just use one battery and smaller panel for the trips when I am not taking the freezer.

In answer to the question on the second-last line of the above post, leaving batteries discharged is a sure way to kill them. Keep them charged up. The Ctek I mentioned above is about $95 online--I have permanently installed plugs on two of my motorbikes with hard to reach batteries so I can keep them up, or use it on the camper batteries. I have used cheaper chargers, but had batteries die undet them, so pay a little extra and get a good one.

 

So to sum up, you can make a sytem similar to the oine above for a $65 battery box, $300 battery, $95 solar regulator,and $40 for some Anderson plugs, Merret sockets and bits of cable.

And for those with the modern vehicles which stop charging once a certain main battery voltage is reached, you will need one of those DC-DC chargers. Modern vehicles really suck in a lot of respects.

Willlo's picture

Posts: 1490

Date Joined: 07/10/11

 Check out the Baintech

Thu, 2016-06-23 09:48

 Check out the Baintech website they will cover yr needs. Retail for around $650. We have sold heaps of them most battery World shops carry them. 

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Posts: 563

Date Joined: 27/08/09

 How to kill a battery!Heat,

Thu, 2016-06-23 11:07

 How to kill a battery!

Heat, Vibration, over dischargeing, not recharging promptly, crappy battery chargers.

 

Run an anderson plug into the back of you vehicle where you want the battery box to sit. Have this relay switched so it disconects when you are not running the engine to prevent drain on your crank battery. A DC to DC charger is a good to manage the battery charge at this point. Some even have an input to regulate solar panels.

Keeping the battery out of the engine bay reduces heat = longer life

Secure the battery and case, and sit it on some PVA camp mats to reduce vibration. = longer life

Try to avoid using more than 25% of a batterys AH capacity. You can go deeper, but you will experience shorter life.

Recharge promptly. Being left in a discharged state will shorten a batterys life.

Most good quality multi stage batery chargers will bring a battery back to charge and maintain it on float indefinatly.

 

Deep cycle batterys are slow to recharge. A couple of hours of engine run time in the car is not usualy enough. A long slow overnight charge with a dedicated charger is realy needed.