Standby ventilation / Installing a secondary battery?

[TB2]

Hello there

so my girlfriend and I are always short on time and now we spontanously decided to go on a trip to the UK for a week. We have time exactly until next sunday, so the sooner we leave, the better. We usually sleep in my BX "Entreprise/Campervan" but we've got one serious problem which is humidity. In the morning the windows are dripping wet and I bet it's not good for the car to get this wet regularly. I also found and cleaned out some mold growing in the trunk a few weeks ago.

An easy solution we found was to just let the ventilation run on low all night which gives us a pleasent breeze, fresh air and keeps the inside of the car perfectly dry. The downside is that the battery is pretty much dead in the morning and the car wont start so we have to find someone to jumpstart our engine.

Now I've thought of alternatives. The ideal approach would be a second battery with a batter isolator. Both batteries get charged while the engine is running but with the engine turned off, one is kept away from the appliances to always have enough juice to start the engine.

Has anyone ever installed such a setup on a BX (turbo diesel) before? Would anyone be willing to help me with this? Getting a battery and some wire is the easy part, but I'm not sure what type of isolator I'd need or where to get it ASAP. Does someone know a source in Brittain where I could pick one up on Monday? The plan is to drive off tomorrow, sleep in France, and take the ferry to Dover on Monday morning, get the parts and install the system.

Alternatively maybe it is enough to just somehow detach the ventilation unit from the rest of the circuit so that it can be switched on without having to turn the ignition. Does someone know if/how that can be done?

Or does someone have a simpler ad-hoc solution for this? Leaving the windows open is pretty bad because of rain, mosquitos (would have to install a net), and also kinda unpleasant safety-wise and the airflow isn't very effective. I also thought that maybe just maybe two computer fans attached to a regular PP9 battery installed on one of the rear air inlets might provide some airflow but the cleanest and nicest solution would be to have the ventilation of the car run over night. An extra battery would also mean that the stereo or even other stuff plugged in could run without any worries of a flat starter battery.

Any help appreciated

Regards

[mat_fenwick]

You can do a simple but effective job using just a standard 4 terminal relay and a 2nd battery - I'll explain more later when I have a little more time...

[Mothman]

Hi Carl,

wouldnt it be cheaper, quicker and a lot more simple and a lot less bother to just open all the windows and drape a mosquito net over the car and then you could go anywhere at a moments notice?
You wouldnt then ever have to worry about flat batteries etc.

Another way would be to buy an extra heavy duty battery, might not fit though.
I certainly would take the easier option.

Andy

ps, oops, forgot to mention, you could also take a tent.
A

[TB2]

Thanks mat, looking forward to that!

Andy, setting up a tent is such a bother Who needs a tent when you have a car. As said, leaving the windows open is impossible if its raining.

I just constructed something using styrofoam, rubber foam, a used sock, an 80mm computer fan, cable and a cork which acts as a panel that I can place into the partially open window which seals the inside from the out and blows fresh air from the outside in and plugs into the cig lighter socket. I'll post some pictures when it's done!

[mat_fenwick]

In my haste to reply I hadn't fully read your message, so a simple split charge system with a relay would only be useful if you rewire the blower motor/radio etc to run off the auxiliary battery instead of the main one.
But, I like your idea (and your sponteneity!) and have another possible (simple but crude) solution...
If you buy something like this

it *may* have enough to help a flat battery in the morning but I wouldn't bet on it. A safer way would be to to simply connect the cigarette socket on that with the on the car, and disconnect the battery overnight.
A simpler solution would be to buy Phil Chidlow's wind deflectors so you can at least have the windows open when raining, but obviously that doesn't keep insects out!

[prm]

Another option rather than installing a complete split charging system. Check out Maplins.

40,60 or 80mm computer fan about £7.00, with a 2-5watt solar panel. Coupled to a small sealed battery positioned in the boot side recess.

Depending on the battery and panel size, you may not need a charge controller, but would recommend a fan speed regulator to maintain a low noise level and possibly extend the running time.

Regards

[Vanny]

Make sure your body exhaust vents aren't blocked up.

Body exhaust stop back pressure in the cabin at high speed, amongst other things, and to get full flow from the blowers you need some where for the air to go. All cars since around the 60's have a body exhaust, some aren't as obvious as others.
On the BX they are quite clear from the outside, that grill just past the back door on either side, its not just a styling feature. It comes out in the boot 'cubby holes' and if your like me then you'll have ropes, sponges, a jack, first aid kit and all manner of gear stuffed in the sides. This means a huge restriction in airflow through the cabin.

Interestingly a lot of modern cars have a body exhaust in front of the rear wheel, who knew!

[TB2]

so we've set over and now we're in Bristol.

The doomsday machine I had built (the one made from styrofoam, a computer fan, a sock and so on) didn't provide enough airflow and just made a ruckus. anyway we're sleeping with all the windows rolled down a bit now and that seems to work well as there aren't any mosquitos around for some reason.

Today the engine overheated the second time after we had to crawl up a steep hill behind a lorry. I pulled over asap and found that the right fan has fallen off again. I screwed it back in place and turned on the disfunctional A/C to get both fans turning and that solved the problem.

By the way, my BX is in dire need of an oil change but I forgot the key needed to remove the sump plug. I've got a new oil, fuel and air filter and before I go looking for a mech to do the oil change I thought I'd ask here if one of you would lend me a hand. We're in Bristol right now and we'll be driving towards Birmingham lateron and around liverpool tomorrow. Does someone with the right tool have some time? I'd bring beer!

[mat_fenwick]

You're not heading into Wales after Liverpool are you? If you are I could give you a hand, the downside being unless you are on the coast you will get plagued by midges!

[TB2]

thanks for the offering, I've sent you a PM!

we're driving around which little of a plan so we're flexible

[MULLEY]

If you're going anywhere near either Chesterfield or Sheffield, then i've got a key you can borrow to take the sump plug out.

[Vanny]

Sounds like i'll be following you up tthe motorway tomorrow. If you get flagged down by a Ford Focus, there will be a sump key in it

You've got PM!

[mat_fenwick]

I think he'll be alright, we've changed the oil and filter, and have just finished drinking! Absinthe as a nightcap maybe not such a good idea...

[Vanny]

good job, did realise you where living in Brum now Mat

[TB2]

Yep, mat helped me out; He's been a great host

Now we're in Liverpool and we'll be on to manchester soon. For some reason the BX is acting up a bit. The temperature warning light sometimes flashes/flickers, I have to keep the A/C switch on so that the fans both keep the radiator cool. It happened just 5 minutes after I had left Mat's place after having driven downhill just using the engine break. And again after starting the car after having it fueled up. I asked a man who was working on a construction site and he happened to be a mechanic, told me that the oil does't show signs of a blown gasket and that I should add some more water to the coolant system. the bottle was half full, I thought that this was about right. Anyway it doesn't seem to be a real problem. The engine runs smooth and goes strong. I just keep the fans turning when driving slowly...

Thanks to everyone who offered help.