Leisure Battery Install - Sealed For Life - Maybe Not!!

[Johnod17]

Thanks deaky
I assume that I could not use a AGM style for the T5?
Your battery location is where I am looking to put it in my T6 (drivers side) ,have you got the dc to dc in the same place with this battery?

 

[Deaky]

There is no reason you can’t fit an AGM battery in your T5.

Yes I have my REDARC under the seat with the battery. Have a look here. Deaky’s Kombi to Camper journey

 

[Johnod17]

Thanks deaky
I will look at your post

 

[Johnod17]

Nice install you have done on your van .
One question I have is will the durite split charger be ok for the agm battery if I use it in the T5. Or will it be no good ?
I can re fit a different 230v charger to charge the AGM on the T5 ,or would it be easier to swap like for like (lead acid)

I will get a AGM for the T6 as I know it is ok for this application looking at your setup.
Thanks
John

 

[Phil_G]

The Durite is a VSR - a voltage switched relay. In a simple dumb-alternator setup these work fine. However in a campervan install these can have one problem that you dont often see discussed: The idea is that once the engine is running, and the alternator begins to charge the starter battery, the higher voltage operates the relay and connects the leisure battery in parallel with the starter battery, so it receives charge current. When you switch off the engine, the batteries settle back down to their rest voltage and the relay releases, separating the two batteries. All fine and dandy. Until you add solar. Some VSRs will operate to the sense voltage on either battery terminal, but in any case once the relay has operated both battery terminals are commoned anyway. Your solar-charger will keep the battery voltages high, and the relay will remain operated, despite switching off the engine, until evening when the solar charge stops. Only then will the batteries drop to their settle voltage and the relay can drop out.
In a nutshell, with a solar system, once the VSR has operated, its stuck until dark. This is great for keeping your starter battery topped up, BUT what happens should you start the van whilst the relay is held in? The traditional D+ relay releases during cranking, but not your VSR - so a significant proportion of starter current will back-flow from the leisure battery.
This could be tens of amps, depending on your wiring - the heavier the wiring, the less resistance and so - the more back-current into your starter motor.

I used to make 'ideal diodes' which is effectively a diode with no voltage drop. Its a high-current mosfet which switches fully on or off according to which direction the current is trying to flow. As you'd expect with a diode, it prevents the leisure battery from providing starter current, whilst allowing charge current in the other direction.
An ideal-diode is a much better solution than a relay in a T4/T5 etc dumb-alternator setup, especially if you have solar. If you want to charge the starter battery from solar, you can temporarily switch a 10A Polyfuse across the diode.

These days they are not worth making - you cant buy the components for the cost of a ready-made board from Banggood: 50A High Power Ideal Diode For Charging Backfill Protection 9-70V Controller Module Board from Electronic Components & Supplies on banggood.com

Sorry to waffle on, to answer the question, your Durite will be ok on the T5, unless you have solar as well.

Cheers
Phil

 

[Spaghetti]

I’ve fitted a Halfords AGM HLB800 under the seat. Just fits.

I always thought AGM were ok on their side, but this says that it can be tilted for ‘short periods’.

 

[T6 owner]

Good info on the Halfords Battery. thanks for posting. Did you fit the Halford's HLB800 Upright, or on its Side ? Did it fit straight onto the Battery mounting plate under the seat ? Is there enough Clearance. I have the same idea to fit mine, the same way if possible. Matt

 

[Spaghetti]

It fits upright and is level with the top of the seat base. There’s enough clearance but it’s worth insulating the positive as it’s close to the fore and aft seat adjuster. I can get a photo tomorrow if it helps.

 

[T6 owner]

Wow, this Forum is amazing. Thank you so much for the fast reply. OK, goo to know it will fit. Yes please and photo of the Top Side of the battery in position to show the clearance with the Seat bottom would be very useful.

One other question, did the Halfords HLB800 battery fit onto the grey metal Battery Tray at the seat base OK too ?

Matt

 

[Spaghetti]

Wow, this Forum is amazing. Thank you so much for the fast reply. OK, goo to know it will fit. Yes please and photo of the Top Side of the battery in position to show the clearance with the Seat bottom would be very useful.

One other question, did the Halfords HLB800 battery fit onto the grey metal Battery Tray at the seat base OK too ?

Matt

Hi Matt,

Please see the photos. the clearance is just close on the lever that adjusts the fore and aft movement. I fitted a plastic cap over the terminal and the adjuster lever slides over that.


Fits in the grey tray. The flanges on the side of the base of the battery are tight on the reinforcement pieces on the seat but fit.

 

[T6 owner]

Amazing. Thank you so much for the photos. They are exactly what I wanted to know before removing everything. Your post has given me the confidence to know that the battery can fit in there. I will get a grey battery tray ordered and all the cables now.

Thanks once again.

Matt