Backup battery

MJVW

Full Member
Hi All,
I would like to fit a battery backup, on my T4 the current leisure battery (75 amp) is located up front under the bonnet next to the starter battery a 50 watt solar panel and 10 amp solar controller provides a bit of extra charge to the leisure battery when off grid. Because of the battery location size restraints dictate the amperage of the battery.

I would like to fit a larger leisure battery under the seating area in the hab area this would be completely separate from the current 12v provisions via the zig unit and would be wired to a usb, 12v socket output unit, so van peripherals can be run from the (back up) battery it would be topped up by a roof mount secondary solar panel.

It could also be charged via built in trickle battery charger when on EHU, because of cost restraint looking to purchase the kit second hand is the Feasible solution?

* I think i will make or purchase a battery box, I guess this needs to be vented? the location of the battery will be over the rear axle, the water heater and water pump are currently in this are so i will put a separation partition in place. should be ok with overall weight.
 

jagmanx

Full Member
Mayb get a lithium power pack unit which dispenses 12v and usb. Many units can be charged off of 12v so maybe get an extra 12v socket and/or a suitcase solar panel to do the recharging. You may not need huge capacity....do the sums.
The most power hungry Item is a laptop maybe 5 or 6 amps at 12v
Use it on battery at night and recharge and /or use it in the sunny day.
Usb 5v uses minimal power but again use as I suggest.
We have 1x85amp- hour lb
Never below 12.6 V..and I have all the toys..

But they stay in the pram
 

wildebus

Full Member
Hi All,
I would like to fit a battery backup, on my T4 the current leisure battery (75 amp) is located up front under the bonnet next to the starter battery a 50 watt solar panel and 10 amp solar controller provides a bit of extra charge to the leisure battery when off grid. Because of the battery location size restraints dictate the amperage of the battery.

I would like to fit a larger leisure battery under the seating area in the hab area this would be completely separate from the current 12v provisions via the zig unit and would be wired to a usb, 12v socket output unit, so van peripherals can be run from the (back up) battery it would be topped up by a roof mount secondary solar panel.

It could also be charged via built in trickle battery charger when on EHU, because of cost restraint looking to purchase the kit second hand is the Feasible solution?

* I think i will make or purchase a battery box, I guess this needs to be vented? the location of the battery will be over the rear axle, the water heater and water pump are currently in this are so i will put a separation partition in place. should be ok with overall weight.
If you get a Sealed Battery you wouldn't need to be concerned about venting the battery or putting it in a box (if the plan is to keep it permanently fitted, I'd just secure it without using a battery box if it were me - a battery box is very handy if you need to transport a battery about, but adds bulk in a permanent installation. No room under the drivers seat for a battery? could get a 100Ah under the seat of a T4.
Would be handy to have some kind of split charge setup so you are getting some kind of charge to the battery when driving? rough cost of that with maybe a basic relay which you switch yourself to maintain control - maybe £40.
 

MJVW

Full Member
If you get a Sealed Battery you wouldn't need to be concerned about venting the battery or putting it in a box (if the plan is to keep it permanently fitted, I'd just secure it without using a battery box if it were me - a battery box is very handy if you need to transport a battery about, but adds bulk in a permanent installation. No room under the drivers seat for a battery? could get a 100Ah under the seat of a T4.
Would be handy to have some kind of split charge setup so you are getting some kind of charge to the battery when driving? rough cost of that with maybe a basic relay which you switch yourself to maintain control - maybe £40.
Very limited space under the cab seats, can't see a battery fitting, thanks for the reassurance regarding battery box i will follow your advice and not get a box , just ensure it is securely fixed in place. Charging will be from solar and see how we get on, but charging while driving would be great would the t4 alternator support charging up front leisure/hab leisure and starter?
 

wildebus

Full Member
Very limited space under the cab seats, can't see a battery fitting, thanks for the reassurance regarding battery box i will follow your advice and not get a box , just ensure it is securely fixed in place. Charging will be from solar and see how we get on, but charging while driving would be great would the t4 alternator support charging up front leisure/hab leisure and starter?
Ref the space under the seats ... if it is not used for other stuff, a battery really will fit (I'm just saying this again as some folk are surprised a battery will fit within the low profile bases).
It is not uncommon to have a pair of leisure batteries in a T4, so the fact one is under the bonnet and one inside makes little difference. If both needed a good charge it would be a higher strain on the alternator but if alternator ok, not a problem. (it is not that uncommon for the addition of a split charge system to expose a flaky alternator. A little embarrassing for the installer as all was apparently ok before, but one of those things).
I am guessing you have a VSR or switched relay under the bonnet between the starter and leisure battery currently? As you want to use the two leisure batteries independantly, I would run a +ve cable between the Underbonnet Leisure Battery and the In-Vehicle Leisure Battery, and have an insolation switch such as this on that cable - https://amzn.to/2Gylhgd
That will let you connect the two together if you want so the in-vehicle battery can get charged on driving, or combine the two if wanted, then turn the switch to separate the two.
You may be able - depending on the size of the existing cable coming into the vehicle from the leisure battery for your current leisure electrics - come off that for this second battery and save the hassle of running a cable from the engine bay?
Not mentioned cable protection in the above waffle .... obviously you need to add in fuse protection both ends, suitable for the cable guage you are using.
 

MJVW

Full Member
Great thank you going to check under seat height, pending on outcome install new leisure battery to best location and secure, then look at purchase another solar panel and setting this up, this could be via a dual battery solar controller so both batteries are charged. Then look at the alternator charge options you have so kindly provided.(y)

Current set up is a switch relay charge system under bonnet.
 

MJVW

Full Member
Have created the space under the bed area, water pump now sits under a removable shelf so I can store stuff it was previously unusable space a 240v socket has been put in the proposed battery storage area for a charger to be plugged in when on Hook up, the 240 socket is a outside waterproof type this was sat in the shed doing nothing so i installed it,


So now looking at the best battery to install perhaps it's AGM and low profile,
12V Xtreme 110ah AGM Leisure Battery (XR1750) , i have also selected it as it is low profile as Wildbus said they can sit under the driver’s seat if i wish to change the location, however i can see how to remove the seat and base.... but would just like to remove the seat and not the base to check clearance how do i do this? So i now have two locations both have advantages and disadvantages just need to make my mind up.

Under seat advantage
Battery in forward cab area on steel floor
Using unusable space
Compact
Secure
Under seat Disadvantage
Battery visible under seat
Tight working space
More work needed to hide wiring etc.
Under bed Area Advantages
Out of view
Larger working area for install (Maintenance etc)
Location would allow the potential for expansion (payload dependent)
Easy cable routing and hidden
Location over rear axle
Under bed Area Disadvantages
Using Space that could be used for storage (small motorhome limited storage)
Battery resting on plywood floor
Battery security needs to be addressed

battery space .jpgnew space .jpgcharger socket.jpg
 

wildebus

Full Member
These are my observations in this colour.


Have created the space under the bed area, water pump now sits under a removable shelf so I can store stuff it was previously unusable space a 240v socket has been put in the proposed battery storage area for a charger to be plugged in when on Hook up, the 240 socket is a outside waterproof type this was sat in the shed doing nothing so i installed it,


So now looking at the best battery to install perhaps it's AGM and low profile,
12V Xtreme 110ah AGM Leisure Battery (XR1750) , i have also selected it as it is low profile as Wildbus said they can sit under the driver’s seat if i wish to change the location, however i can see how to remove the seat and base.... but would just like to remove the seat and not the base to check clearance how do i do this? If you look at the photo below, you will see the securing bolts - one in each corner. At the back they are Hex Nuts. At the front they may be Hex or may be standard nuts (seen both).
For your setup, if you DID fit the battery within the seat base you would not need to remove the base (only really need to do that if running cables under cable to bulkhead. In fact, if you move the seat forward all the way as shown, I reckon you could even drop the battery in without removing the seat!


So i now have two locations both have advantages and disadvantages just need to make my mind up.

Under seat advantage
Battery in forward cab area on steel floor
Using unusable space -- This is how I used the space within my T4 Seat Base ....
48417
Now this is something you may or may not be aware of ... there is a stop on the seat runner that stops you sliding it very far forward. You can release that stop (or even remove it - most people do that) and you can slide the seat all the way like in the picture above and get access to the whole inner base area.

Compact
Secure
Under seat Disadvantage
Battery visible under seat -- You could make a cover quite simply for this. This is a photo of the seat base cover that was on my VW LT Base to protect the electrics.
48418
This was made from hardboard. I made 2 copies from 3mm ply - one for each seat base
Tight working space -- Not bad actually once seat is all the way forward if you need to access it. Once done, very little reason to have to revisit it (battery is 100% maintenance free)
More work needed to hide wiring etc. -- yup. need to run a pair of cables of 16mm minimum from seat base area to original battery
Under bed Area Advantages
Out of view
Larger working area for install (Maintenance etc)
Location would allow the potential for expansion (payload dependent)
Easy cable routing and hidden
Location over rear axle
Under bed Area Disadvantages
Using Space that could be used for storage (small motorhome limited storage)
Battery resting on plywood floor
Battery security needs to be addressed
To me personally, if you can tuck the battery under the bed out the way, that would give both the easiest install (assuming you can address the battery security side - can you secure to the bed framing as well as into the floor maybe?) and the best option electrically (shortest cabling between batteries).
Storage wise, can't comment on comparing between the two other than to refer back to that first photo to show the underseat area is maybe more accessible and usable than you may have considered?
I even made a couple of bases to use as little seats/shelves when parked up (didn't have swivels in the T4 as took them out soon after fitting)

48419
(carpeted 19mm bases with little locating strips to keep in place on base)

Hope this was of some help/interest.
 

MJVW

Full Member
Wildebus love the little seat very neat idea thanks for your sound advice, going to purchase the battery and play around i think under the bed is an easier option should be able to secure on floor and to bed frame.
 

MJVW

Full Member
12V Xtreme 110ah AGM Leisure Battery (XR1750) ordered from Alpha batteries plus membership discount happy.
 
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