Twin Leisure Battery under Boxer seat?

Has anyone tried squeezing two leisure batteries into the leisure battery box under the driver's seat of a Boxer Symbol or Symphony PVC?

We want to do "off grid" camping... both summer and winter... in our recently aquired Boxer Symbol. It has no solar panel, so we need to get something sorted. But to make effective use of a solar panel, we'll need to upgrade the leisure battery capacity.
 
The leisure battery on these vans is situated in a pretty small space (235 high x 350 wide x 270 deep) under the drivers seat. The reasonably new leisure battery we've inherited is a Numax CXV 75Ah (220 high x 257 wide x 172 deep), which I'm guessing is pretty under capacity for what we want. 
Having looked at what could replace it, the largest that'll squeeze into that space would be a 110Ah. 
However, it looks like if I get another battery similar to that Numax... there is a Numax 80Ah available... the pair will JUST (theoretically) sqeeze into the available space. If successful, I'd have 155Ah for only another £90 (plus cables and connectors) and not have to use very limited space elsewhere.

I could just lash out £90 plus bits, and try it. But I can't see any harm in asking for advice first.
Anyone done it? If so, any pitfalls?

When I had a Symphony I could not find a larger amperage battery that would fit. Normally a larger amperage means larger physical size. If not length or width then the height is the problem. You don't want the terminals touching the underside of the seat. We never had solar on the Symphony but did have an 80w panel on our Nuevo and only had one 75amp battery. We regularly stayed on sites for 5 days without hook up and not going off site and never had a dead battery in 4 years.

pilchard wrote:But to make effective use of a solar panel, we'll need to upgrade the leisure battery capacity.

One of the pitfalls here is that you need to be sure that the output from your solar panels can put back all of the capacity that you've used, every day - even if you have several overcast days in a row in Spring or Autumn.

If it can't you run the risk that you'll have several partially-charged batteries rather than one fully-charged one - and operating for anything other than very short periods in a partially charged state is bad for any lead-acid battery.

IMO you are better off sticking with a single (as large as will fit) leisure battery and managing your power use, unless you can afford to put on a lot of solar capacity. Fortunately the trend to use LED lighting has led to lower power use for the essentials, so this has become a bit easier than it used to be.

Hi,
I did manage to fit a second battery of the same size next to the original on my 2001 symbol. First remove seat, then remove battery tray, remove or flatten the battery retaing bracket to give a flat surface. Batteries need to be turned 90 degrees, also packing needs to be inserted so that the battery is not standing on the holding down bolts for the tray. Only problem now is finding an alternative mounting for relays and fuses. It can be done but it is awkward,
Good luck

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Yes, I've removed the original tray and replaced with a deep plastic tray(Gratnell). Tie down straps hold both tray and batteries in place.

Don't see the need, and wouldn't want any unnecessary weight. Would also be ultra fussy about a, possibly, poorly restrained 50Kg load full of acid under my seat!!

Being more serious, we have a Duo, original, as far as I know, leisure battery, 110Ah or so. I fitted a 140w solar panel. We virtually never use an EHU (unless its cost is part of a site fee) and have never had any battery issues. The solar keeps both the vehicle and leisure batteries full all year round. My total weight increase with this system was 6Kg. Below is how it was done.......
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we have a 2011 Warwick duo we have a leisure battery under each seat ( drivers and passenger) easy fix plus 120 solar panel ,use year round never ran out of power, heater on all night if needed

The diesel heater in our Symbol is a hungry beast on site during the winter , only having the one battery wouldn't last more than two day/nights even at the most economical setting.

Thanks for all the very helpful replies.
What chrivesey did is what I had in mind... and I'm quite capable of doing the tinkering and also leaving it safe.
crosgor's version is something I hadn't considered, but a possibility... although maybe of last resort.
-mojo- got me thinking a little deeper, and he has got a very fair point.
But I think Paulmold has hit the nail on the head. His van was lasting more than 5 days without charging with anything other than the 80w solar panel... probably running older (non LED lights), probably with a TV and phone charging, and probably using the blown air from time to time. Fresh water, grey water, and toilet capacities (not forgetting clean clothes) could only just about be stretched to 5 days before the need to go on-site, so It might be quite possible... with an up-to-date spec 100+watt panel, 75 Ah battery, LED lights, no TV but laptop instead, mobile phone charging, and occasional blown air... that we'd cope, and I'm trying to fix an imaginary problem. We've always felt that 5 days wild and 2 days on-site would be a perfect balance anyway.
So, on balance, I'm now thinking I'll get the solar panel (that'll need another thread on the forum I suppose) and battery-wise... suck it and see; for this first summer anyway as the hours of sunshine in the Dolomites are pretty high. As for winter jaunts in Scotland... well, we'll see, later.
Oh, by the way crosgor... our heater is blown gas powered. Although I know it works, we've not had the van long enough to see what damage it does to leisure battery power. But 12v consumption of the heater has always been my main concern re battery. I used to have a Transit camper and the Propex gas heater in that used to just kill the 100Ah battery in cool weather: so much so that I had to double up the battery. Paulmold has told me not to worry; if we run out of 12v and freeze from lack of blown warm air... I'll get on his case ;-)

pilchard wrote: Paulmold has told me not to worry; if we run out of 12v and freeze from lack of blown warm air... I'll get on his case ;-)

Before you blame me, I'll qualify my earlier response - the set up on our Nuevo had a gas fire which was great without a fan but we didn't use gas through the night except for fridge. From around Easter to end of September we rarely went on proper sites preferring C&CC temp holiday sites. Also we go to a lot of outdoor motorhome shows which last 5 days. We did have led tube lights. Now we have the Sussex, I've swooped spotlights to LEDs, we don't have a traditional gas fire but now have blown air heating but hoping that between Easter and end of September we won't need much heating. We do use TV for maybe a couple of hours. Obviously I'm hoping that the similar solar system that is to be installed will provide similar power maintenance.

Hi Paul. I was only pulling your leg... but you probably sussed that.
Having had experience of the old-style convector heater and a propex blown air unit... I'd have the convector any day. Totally silent, requires no electrical connection, warms up quick enough if you don't mind a 5 or 10 minute wait and... unbelievably warm in even serious sub zero conditions.
Of the two approaches to this little quandry re battery capacity, I think I'm still now leaning towards "suck it and see" rather than "belt and braces". I just have memories from 20 years ago of that Propex heater gobbling up the power from a pretty substantial battery. 
Still... if it comes to the worst... and you can get the odd cool evening in the Dolomites as well as grey/wet days... they sell leisure batteries over there, I speak reasonably good Italian, so that tandem battery option would still be possible.

Pilchard

Don't forget, though fairly sure you won't that your vehicle alternator also charges the LB. Paul's case of 5 days in one place, presumably without using the engine at all, is quite rare.

Should you find yourself on a site you'll poss have EHU as well.

My experience of 1 x 110Ah and a 140w solar panel is such that we have never had a problem, the real benefit of the solar, however, is NOT just for use when using the van, but, especially to keep both batteries 100% full all year round

Yes IanH... I have been been factoring in a possible 20 or 30 miles per day, plus the electric hook-up when on-site. 
As I have yet to install a PVP, or even decide on which one... I might be inclined to er on the side of caution and go for the largest I can find space for on the roof. Those thin flexi jobs seem to be the business.

Bimble Solar still have the 150W flexi panel at under £200 - which is what we used on the Trooper - if it's the right size for your space. Not exactly local to you though (they are near Brighton)!

You just read my mind -mojo-... I just started a thread on chosing and sourcing panels. That particular panel is too big for available space on my roof. If only life was so easy.
Please everyone... have a look cos I welcome any input.

Ah yes, I see from your other thread that's waaay too big. We're fortunate on both the Trooper and the Celex to have loads of free area - but the downside for us was installing cabling that will cope with a roof that goes up and down!

Some of the Chinese panel sellers ~say~ that they will custom-make a panel any size or shape you want (obviously within the constraints of the size/shape of the individual cells). That might be worth exploring, though I did not get as far as getting a quote when I looked into it.

-mojo- wrote:Some of the Chinese panel sellers ~say~ that they will custom-make a panel any size or shape you want (obviously within the constraints of the size/shape of the individual cells).

That could be worth exploring -mojo-. any links?
What was your take on quality/output etc?
Have had a couple of not so good experiences ordering from China, in terms of quality, so would have to be very... circumspect.

Sorry - any links I had would be 4 years out of date! My experience of buying from a Chinese supplier (with UK stock) was not that great. Packaging was inadequate and the panel was cosmetically damaged in transit - though it still works absolutely fine and the damage is near enough invisible from the ground.

Our experience of a UK supplier (Bimble) wasn't comparable because we were lucky enough to be able to go there and collect, though they do have extensive experience of shipping panels around the UK.

It's very difficult to compare the two because each has a completely different type of controller (twin-channel PWM controller, 100W panel on the Celex, single-channel PWM + VSR, 150W panel on the Trooper). It appears that the more recent panel has significantly better low-light performance than the older one, but that's just casual observation rather than testing with any method to it.

I doubt you will be able to perceive any difference in quality between Chinese or UK-supplied. The Chinese government have invested so much in their (over-) capacity that it's fairly rare to find any that are not made there these days, and those that appear to be made in Europe probably have mainly Chinese components anyway! The electrical connectors on both of the panels that we bought were unimpressive, but that didn't matter to me as I cut them off and wired the panels in directly - I did not want big ugly push-fit connectors flapping about on the roof...

Photonic universe for semi flex panels, many different sizes.
Theyve been great with me from day 1, if not I wouldnt recommend them