Dual Battery Options and Fitting

[Mtwem]

Hey all.

Been enquiring and looking to put in a dual battery before chrissy.
Have a 2010 T5.1 Transporter, Barn seats in the front.
Was going to place the dual battery setup under the barn seats in the storage compartment.
Have a couple questions regarding it if anyone has any knowledge or links to help that would be great as I could not find too much info for rookies on the dual batterys such as myself.

Was planning on mainly using it for:
Waeco Fridge/Freezer
USB charger
Lights
and potentially Stereo if it's not tricky to do.

I've never had experience with dual batterys before.

1. Is deep cycle the way to go? and if so, whats the best to go for what i'd be using?

2. What are the parts required other than the battery itself?
I went into Autobarn and had a chat with a guy there who mentioned that i would have to spend an extra 400$ on a part because the transporters' run a 'smart alternator' that doesnt run on idle? is this correct? Obviously my ignorance isn't a help here and would love to keep costs at a min.

3. How's everyone set it up with the wires running from the OG battery to the new under the seat? Whats the best way to run them.

Would love to DIY this one, as my mate recently got his iload setup with one and paid a ****load of money for it to be setup, when my electrical friend said it would cost less than half that to do ourselves.

Any help is greatly appreciated !
Cheers

[Pickle]

I'm looking at doing the same thing and will use the Ctek smart charger with solar option. easier to spend more now that have to revisit the job in the future.

12V Bundle Multi Tool Smart Battery Charger | CTEK | Edisons

Thats a high price, look on ebay for a cheaper price.

When I removed my dual seat I found a nice big fat positive cable all taped up under the seat so i hope thats a direct connection to the battery so i don't have to run a new cable. I've replaced the twin seat with a single as i want the walk through function, that means I may have issues finding a home for the second battery.

I would go for a fully sealed battery maybe a AGM around the 80Ah size so it can run your freezer for a while off line, I will be using it for similar uses to you, freezer, lights and power.

Would be interested to see how you go.

[winchy]

This guy has helped quite a few Amarok owners out.. SC80 | TRAXIDE - RV | Traxide - RV

[Pickle]

Interesting

[Sunny43.5]

I was talking to a guy at Battery Traders in Moss street the other day he was really helpful , as I was toying with an extra battery but could not justify the price and effort as we only usually camp for two days and our vans battery copes quite well as it is .

[Transporter]

Interesting indeed, though I still prefer bcdc 3stage charging which is better than just charging from the alternator especially if the starting battery is flooded lead acid and your second battery is AGM/Gel or other.

Hint to those who choose the REDARC BCDC charger. Choose BCDC 1225 over 1240, unless your second battery is at least 200Ah (overcharging will shorten the battery life).

[Gold Coaster]

Is deep cycle the way to go? and if so, whats the best to go for what i'd be using?

Unless you want to spend up big and go lithium, I would recommend an AGM (Absorbed Glass Matt) battery. These deep cycle batteries are sealed so are safer in a confined space then a conventional wet cell battery. They can also be laid on their side which sometimes helps when you have a tight fit.

With regards to what size AH (Amp Hours) battery to get this all depends on a number of factors such as are there any physical size restrictions or weight restrictions.

Also you need to work out the total number of amps that your appliances will be drawing and then calculate how long the battery would last before having to recharge (taking into account that for battery longevity it is not recommended to discharge below 50%).

Having said that it is equally important to take into account how you plan to, and how often, you will need to recharge the battery i.e. only when driving via alternator or will you have solar panels or maybe a generator or will you be using 240v mains and will it be mainly just overnight or a weekend or longer?

Good luck, they're well worth installing!

[jonathan_k]

I have mounted a 135AH AGM battery under the drivers seat on its side, which is safe to do with AGM batteries. Rearranged some of the wiring that was there.

I'd recommend a DC/DC charger too. I kept a Redarc BCDC1225 from a previous vehicle though if I had to get another one I would go with the Projecta IDC25.

There is an anecdotal measurement of AGM battery value which is to calculate the "cost per kilogram" and couple this with the warranty which the manufacturer offers. Based on this the PowerAGM brand from eBay seller autoelecau is good value. 6 months in and no issues to report.

Size? You'll never complain about having too much stored power! There's a sweet spot in terms of value around 120AH.

I ran a 6 B&S cable from the main positive, through the rubber grommet located behind the battery tray into the passenger footwell. Make sure there is a downward loop on the outside to stop water running down the cable. From there, there is a cable channel across to the drivers seat (you could just go to the passengers seat).

Fuse both ends and mount the DC/DC as close to the auxiliary battery as possible, mine can be seen on the side of the seat base in the photos below. The other thing in the photos is a shunt for my battery monitor which you won't need. Earth to the chassis through the seat bolt.

I've done a few, can give you whatever info you need if you're keen to DIY.

[ericcs]

as mentioned above, go the Projecta IDC25, you can get them as cheap as $250 of ebay. also, gives you the option to connect a solar panel!

[Mtwem]

I have mounted a 135AH AGM battery under the drivers seat on its side, which is safe to do with AGM batteries. Rearranged some of the wiring that was there.

I'd recommend a DC/DC charger too. I kept a Redarc BCDC1225 from a previous vehicle though if I had to get another one I would go with the Projecta IDC25.

Great info thanks heaps for the walk-through!
Pretty straight forward running the cables through and under the grommet and side step into the passenger side?
Think I'll most likely get one of the AGM's - is it safe to go lower in amp hour with my use or is 135 a safe bet?
And sorry for my ignorance, all rather new to me, but is the Projecta IDC25 what the bloke at Autobarn was mentioning i'd need for the fact that T5's run the smart alternator?


In regards to usage, I'd mainly use the fridge for weekend trips but potentially throughout the week to keep a couple things in there. drive every day to and from work and everywhere in between. Potentially solar panels in the future but not for the time being.
thanks everyone for the help
Looking forward to installing!

[Gold Coaster]

Think I'll most likely get one of the AGM's - is it safe to go lower in amp hour with my use or is 135 a safe bet?

Definitely go the biggest battery that you can physically fit in, especially if you are relying solely on your vehicle's alternator to do the recharging.

I'd mainly use the fridge for weekend trips but potentially throughout the week to keep a couple things in there. drive every day to and from work and everywhere in between.

If the alternator is your only means of recharging your auxilary battery don't expect to be able to keep your Waeco Fridge/Freezer running 24hrs a day.

Running time will depend on how big the Waeco is as to how many amps it will draw on average. Also where the car is parked during the day has a big bearing as the air temperature in a closed vehicle in the sun will keep result in the thermostat keeping the fridge working continuously. Another factor is the number of hours you spend driving.

So that you won't be disappointed you need to do the maths first so that you will know what the limits are.

[Sunny43.5]

I posted this link the other day on a post about extra USB outlets , some good facts and suggestions .Power and Charging Guide / Power and Charging Guide / Portable Fridges Portable Fridges Camping Fridges

[jonathan_k]

Great info thanks heaps for the walk-through!
Pretty straight forward running the cables through and under the grommet and side step into the passenger side?

Yeah, just work it out as you go and remove covers and carpet as necessary. You'll have to make a new hole or enlarge the hole in the grommet. I'll try and get a pic of mine. For running cables I like to use white curtain wire, feed this through as a leader and then you tape the actual cable to the end and pull it through. A bit of clean oil will help get it through the grommet.

Think I'll most likely get one of the AGM's - is it safe to go lower in amp hour with my use or is 135 a safe bet?

Check your dimensions first, the battery I have is snug under the drivers, perhaps you have more or less room? As Gold Coaster said above, usually you'll calculate your usage and aim to not discharge below 50% regularly, occasionally is OK. Below 30% discharge will quickly degrade the battery. Say the average draw of your fridge is 1.5Ah and you want to run it for 24 hours without charging. It will use 36Ah and you'd require 72Ah of stored power following the 50% rule. There's a calculator like Camping Warehouse - Solar Power Calculator if you want to go down that path.

As a value proposition, the price difference between an 85Ah and 135Ah (around $50) seems negligible against the time you'll invest in installing it and then relaxing not worrying if you're destroying your battery. I'm biased toward my own usage of course. If you know that you're going to drive a couple of hours every day or every second day then you can get away with an 85Ah or even like Sunny does, just run off the main battery.

And sorry for my ignorance, all rather new to me, but is the Projecta IDC25 what the bloke at Autobarn was mentioning i'd need for the fact that T5's run the smart alternator?

Yep. I'm not sure if the T5 has a smart alternator, it's likely which makes a DC/DC charger a necessity. Regardless, a DC/DC charger has several other worthwhile benefits which you can research. The Redarc stuff is high quality but you'll pay for it.

[jonathan_k]

Forgot to mention that your biggest drama will probably be crimping the terminals onto the ends of the cables, which is much easier with a crimping tool if you know someone. Whereabouts in Sydney are you?

[Mtwem]

If the alternator is your only means of recharging your auxilary battery don't expect to be able to keep your Waeco Fridge/Freezer running 24hrs a day.

Running time will depend on how big the Waeco is as to how many amps it will draw on average. Also where the car is parked during the day has a big bearing as the air temperature in a closed vehicle in the sun will keep result in the thermostat keeping the fridge working continuously. Another factor is the number of hours you spend driving.

So that you won't be disappointed you need to do the maths first so that you will know what the limits are.

Thanks mate good to know! looks like the fridge will be running roughly 1 AH per hour or so.

• I posted this link the other day on a post about extra USB outlets , some good facts and suggestions .Power and Charging Guide / Power and Charging Guide / Portable Fridges Portable Fridges Camping Fridges

  great link cheers.

• Forgot to mention that your biggest drama will probably be crimping the terminals onto the ends of the cables, which is much easier with a crimping tool if you know someone. Whereabouts in Sydney are you?

  not wrong there luckily i have a crimping tool from one of my pliers from work - located on the northern beaches in narrabeen. thanks for all your info and help jonathan! been a huge help. dimensions seems to be sweet as under the barn seat has plenty of room. if you do get around to taking a photo of your feed that would be epic. thanks mate