Dual Battery Options and Fitting

[Transporter]

I have been working in this industry for nearly 40 years, designing and manufacturing electrical and electronic products, used in this field and for a number of years I was also a partner in an auto electrical service.

So I have gained some relevant knowledge about alternators over the years.

Me too.

[jonathan_k]

Hi folks and before you go fitting any form of DC/DC device, you should do a lot more research into what is available.

Even with EURO6 alternator operations, with STOP/START, you can get MUCH better auxiliary battery charging results by NOT using a DC/DC device.

I am not a sponsor on this site so I will not spam it, but do your research and you will find, if you do a fair bit of city driving, you can actually improve fuel consumption if you fit the correct type of isolator.

Whereas, fitting a DC/DC device may not only increase your fuel consumption, but it WILL take up to 4x as long to recharge a low auxiliary battery compared to what your alternator can do when connected directly ( via and isolator ) to your auxiliary battery.

Perhaps we can rescue this thread!

drivesafe, you're obviously passionate about this topic. Can you give a relative and constructive recommendation for a common dual battery setup for a Transporter owner? You can see that we're regularly mounting batteries under the front seats (less than 3m cable run). Single battery 90-135AH. The T6 owners have stop/start but most of us don't. If you're not comfortable mentioning your product, just say "Product X"?

Edit: Also please mention your battery recommendation!

It's hard to be deeply knowledgeable about more than a few subjects, so most of us do our best by processing the best information we can find.

[drivesafe]

Hi Jonathan, I am only too happy to try and be of some assistance for those wanting to set up a dual battery system, but as I have posted, I am not a sponsor on this thread, so I have no intentions of spamming the site.


I will start by following up on your request for battery recommendations.


First off, as may have already become obvious from my earlier posts, you can’t really just pick any battery and job done.


To set up properly, where you get the best from a dual battery system, the battery type needs to be selected to best suit your needs/requirements.


For example, the first question is, how often do you drive your T5/T6.


Is it your everyday vehicle, if so, then any battery type will be fine.


But here, some types of batteries will offer benefits that others don’t. Benefits like speed of recharging. This can be very important if you only do a lot of short drives.


Is your vehicle only used on weekends, and if so how long would you drive it for, when you do drive it.


Is your vehicle parked up for weeks at a time, and if so how long would you drive it for, when you do drive it.


In all of the above use types, when you do go on a trip, how much reliance do you put on your batteries.


Do you simple move from powered site to powered site and only use your battery to maintain a fridge while you do your tourist bit, between powered sites.


Or do you sit in one place, off the grid, for days or weeks at a time.


All these questions should to be considered before any suggestions of what might be the best battery for a given use.


If anyone wants to post up their uses, based on above, or any other types of use, please do so and I will try to help to sort out which battery might be the best for your particular use.

[Markee]

Drivesafe. I'm after an auxiliary battery that will be used in a car that is driven everyday as a work vehicle, then on the weekends and holidays it is used for camping trip on sites without power available for days at a time.
I would like it to power a fridge, some basic LED lighting and down the track an inverter to charge my work tool batteries and small batteries, like phones, while on camping holidays.
It must be able to receive charge multiple ways. ie. alternator, solar, 240v.
It also must fit on/in the factory battery tray under a T5.2 front passenger bench seat.
I will be using a Ctek D250S charger.

What battery would you recommend?

[John Deere]

With the info from Bryn I think the $450 VW option is pretty decent.

[hoddy]

What battery would you recommend?

Hey Markee, I ordered online and received the Varta F21 AGM today. $439 delivered.
It’s 315mm long and fits under passenger seat perfectly.
Previously had the factory fitted version that was the same as the starter battery. This and an optima 55Ah 3rd battery both died recently, after 7 years in a 2010 4motion.

Am keen to see how the F21 AGM 80Ah beauty performs.

Am also upgrading the 30 year old BP solar 65watt panel to a 100watt panel that lives on the roof permantly.

I need a new Solar controller that will also charge up the starter battery - any suggestions anyone??

[Bryn23]

Hey Markee, I ordered online and received the Varta F21 AGM today. $439 delivered.
It’s 315mm long and fits under passenger seat perfectly.
Previously had the factory fitted version that was the same as the starter battery. This and an optima 55Ah 3rd battery both died recently, after 7 years in a 2010 4motion.

Am keen to see how the F21 AGM 80Ah beauty performs.

Am also upgrading the 30 year old BP solar 65watt panel to a 100watt panel that lives on the roof permantly.

I need a new Solar controller that will also charge up the starter battery - any suggestions anyone??

Votronic do a MPPT Solar Reg with a starter battery charge, although it is 1 amp, I've got a 350Watt version lying around that i didn't end up using.

I can send you the PDF english manual if you like as it has the smaller watt versions with all the specs and install.

https://www.solar4rvs.com.au/mppt-solar-charge-controllers-votronic

[Bryn23]

Hoddy, im not sure if you have looked at your solar panels, but i ended up going with the eArche flexible solar panel with the 6mm alum frame. (they have 3 different frame versions)

They were released late last year, and are made for Commercial and Residential dwelling use and come with a 10 year warranty.

I opened up the junction box on mine and it is completely sealed, a lot out there on eBay aren't.

I quite impressed with the quality, i ended up with the 180 watt version

https://www.solar4rvs.com.au/solar-panels/flexible-solar-panels/earche/

http://www.energus.com.au/earche-solar-panel/

[hoddy]

Thanks for the info Byrn. The 100W panel is already on the way, although with a flexible panel I thought it would be difficult to affix to the T5 roof with the ribs running along it. Does yours have a pop-top which is flat?

Will have a look at the PDF of the Votronic. I guess 1 amp is probably enough for the starter battery. The other regulator that I was looking into was the Morningstar Sunsaver Duo.

Cheers.

[Sunny43.5]

This came up on Facebook today , interesting concept as you would not need to permanetly fix it to your van etc . 12V 18V 100W Folding Solar Panel Kit Flexible Charger Blanket Caravan Camping RV | eBay

[Transporter]

What battery would you recommend?

In my T5 4mo, I’ve used 75Ah Powersonic battery from my local IBD supplier. It was connected to Projecta 20A DCDC 3stage charger. It was powering 1000W inverter to run laser mono printer, wifi modem, various chargers and power tools. I’ve lost the track how old the battery is, probably +7 years and is still good. It cost around $160. The same brand battery in 105Ah is in low $200 today and it will be fitted in my new van which arrives soon and I’ll be using a new Projecta 25A DCDC charger that has also solar panel input and can be had under $300, it can be fitted under the bonnet and it’s fully sealed.

You don’t have to overspend when buying the battery.

[Bryn23]

Thanks for the info Byrn. The 100W panel is already on the way, although with a flexible panel I thought it would be difficult to affix to the T5 roof with the ribs running along it. Does yours have a pop-top which is flat?

Will have a look at the PDF of the Votronic. I guess 1 amp is probably enough for the starter battery. The other regulator that I was looking into was the Morningstar Sunsaver Duo.


Cheers.

Ive got a ribbed roof on the Mid roof as well, i decided to make up a aluminium frame to give the panel a air gap and allow for easy replacement if the panel fails.

Panel is attached with doubled sided tape and rivets in the supports, frame is attached with 2 tubes of Sikaflex 252

[Markee]

In my T5 4mo, I’ve used 75Ah Powersonic battery from my local IBD supplier. It was connected to Projecta 20A DCDC 3stage charger. It was powering 1000W inverter to run laser mono printer, wifi modem, various chargers and power tools. I’ve lost the track how old the battery is, probably +7 years and is still good. It cost around $160. The same brand battery in 105Ah is in low $200 today and it will be fitted in my new van which arrives soon and I’ll be using a new Projecta 25A DCDC charger that has also solar panel input and can be had under $300, it can be fitted under the bonnet and it’s fully sealed.

You don’t have to overspend when buying the battery.

Cheers mate just what I wanted to hear. Trawling Ebay now. Hoping for a 120Ah+ that will fit in the available space.

[Mtwem]

Cheers mate just what I wanted to hear. Trawling Ebay now. Hoping for a 120Ah+ that will fit in the available space.

I used these guys, big range, and the 120/130 fit under my seat snug.
Quick delivery and decent price.

Deep Cycle Batteries|AGM Deep Cycle Batteries |12v Deep Cycle Batteries |Solar Batteries |Deep Cycle

[hoddy]

I think my 15 year old Pirahna Solar controller is dead. I installed the new 2nd battery and 100W solar panel a couple of days ago. I tested things today while parked in sunshine - battery was over 15volts and there was 4 amps going to battery. Solar controller had a yellow light on it which means only tricle/ float charge should be going to battery, but I reckon the controller is stuffed.
I have since disconnected the panel to preserve the battery.

It might explain why the previous optima & stock leisure battery both died....

What ya reckon?
Should only charge at 14.3-14.5, and float at 13.7 or so.