Electrical help

[Taff Thomas]

We've just collected Margot, our new (second hand) VW LT35.

She has two "leisure batteries", and other bits and bobs which I am totally unfamiliar with.

Can some kind person give us advice on using and managing this system?*

Treat us like idiots, we are totally uninformed.

Next up, how do we use the gas system!!

Thanks in advance for your forbearance.

BROKEN LINK
BROKEN LINK
BROKEN LINK
BROKEN LINK

* we did ask the nice people we bought it off, but we were so swamped with info on the van it's all gone out of our heads.

 

[sueandjohn]

I can’t help but if you google “Vw lt45 instruction manual” you will find what you need I guess/hope . Good luck

 

[Taff Thomas]

Thanks, I'll try that.

Any basic info is appreciated, things like "How do I switch to the leisure batteries when parked up and not connected to the mains".

ETA; Searching "Vw lt45 instruction manual" gives me the van manual. I'll see if there's one for the leisure battery system.

 

[Southdowners]

Can you email the people you bought the vehicle from and ask them to email written instructions to you?

 

[funflair]

Well at the top you have your 12v distribution unit with lights down the left side that are self explanatory I think, you can only use the charger when the red "Mains input supply" is on the three bottom lights are a rather basic battery meter. Then you have switches and fuses for the fridge and and water pump, the fridge switch has a fuse at 15 amps or something so this might be to switch it while you travel and the test of the time it needs to be on gas or main electric as your battery would not support the fridge on 12 volts without engine running.

I don't know what the rocker switch under the 12v unit does so a bit of investigation required here, it could just switch the charger on/off when plugged in.

The battery is a sealed GEL unit, I guess not exactly matched to the rather basic charging unit in the second picture but if it work its OK.

The bottom photo is the 240v control/fuse panel with main isolation and trip then breakers to supply some sockets and the fridge, of course this only works when plugged into an electrical source but 240v operation of the fridge would be your best option when you have power.

Martin

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[Taff Thomas]

Crikey, cheers Martin. Some learning to be done on my part!

 

[autorouter]

To start right from basics, most of your essential electrics will be working off the 12V leisure battery. The water pump, the internal lights, the fridge control board etc.

When the engine is running, the engine alternator will charge the leisure batteries as well as the starter battery. The leisure battery will last probably a couple of days when you are camping.

If you want to charge up the batteries without running the engine, and you can get access to a mains supply, the inbuilt charger will charge up your leisure batteries. It may or may not keep the starter battery charged up, some vans do, some don't. You will have some mains sockets, that will only work if you are connected to the mains (the term is Electrical Hook Up, or EHU).

"How do I switch to the leisure batteries when parked up and not connected to the mains".

You don't have to do anything, it should all 'just work'. British vans generally have a device that switches off all the leisure battery powered items while the engine is running (except the fridge). This is automatic, and again you won't have to do anything about it.

When you are camping and connected to EHU, you may need to switch the charger on. Most people just leave it on all the time. When you disconnect from the EHU, it will stop charging obviously, but it won't need to be disconnected or switched off.

The mains box (Consumer Unit) looks good. It has a residual current device (RCD) that protects against electric shock, that's the one on the left with the test button. It has three miniature circuit breakers (MCBs) that protect against overcurrent and fire. I'd guess one of the MCBs is for the charger.

I'm guessing you don't have an inverter (most vans don't) so the mains electrical sockets will only work when you are hooked up to the mains supply.

 

[Taff Thomas]

Many thanks mate, that's made it even more clear.

 

[Camdoon]

Things will become clearer after you have used the van in earnest. We have all been there.
Once you are happy with it all you may want to think about buying spare fuses as your 12v distribution unit has told you the size you need. Fuses tend to blow in accordance with Murphy's Law (i.e. always) when you are in the middle of nowhere at night.

 

[Taff Thomas]

Great tip CA!

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[autorouter]

Once you are happy with it all you may want to think about buying spare fuses as your 12v distribution unit has told you the size you need. Fuses tend to blow in accordance with Murphy's Law (i.e. always) when you are in the middle of nowhere at night.

A very good point. Fuses for these panel-mount fuse holders are different physical dimensions, and are mostly not the same as mains plug fuses. They can be difficult to get, away from big towns or abroad. I'd suggest Maplins, but sadly that's not an option for much longer.

The picture shows a Numax Gel leisure battery, 104 amp-hours capacity. You said there are two, so I'm guessing the other one is identical. That's 208 amp-hours, which is quite respectable for a small motorhome. The first thing to remember is to not discharge them until they are completely flat, and never leave them for long in a discharged state. Keep them charged up, especially if not using the van for long periods.

 

[Taff Thomas]

Can you explain what you mean by "not discharge them until they are completely flat," mate?

 

[MisterB]

basically, don't let the batteries go flat OR use the battery power so much that you flatten the batteries yourself.

 

[Riverbankannie]

I think you might find it useful to buy one of these s/h very cheap and full of good information
https://www.ebay.co.uk/itm/Haynes-Motorcaravan-Manual-Hardback-Book-by-John-Wickersham-/352341116417

 

[autorouter]

Can you explain what you mean by "not discharge them until they are completely flat," mate?

Did I really write that? OK, what I meant was, do not discharge them to the point where they are completely flat.

Example. a 100 amp-hour battery will in theory supply 5 amps for 20 hours. At that point it will be completely flat. Because of the production variability of the cells inside the battery, some cells will be not quite flat, and somewill be excessively discharged to the point where they are a bit reversed. If you try to recharge the battery, it is possible it will be permanently damaged and will never recover.

For standard lead-acid batteries, most people agree that you should aim to only discharge the battery down to 50%. So for the 100 amp-hour battery, 5 amps for 10 hours (50 amp-hours) is about the limit of what you should extract.

However your batteries are Gel technology. Still lead-acid, but the acid is made into a gel. Some people stick with the 50% limit, but others say you can take more power out, down to the 20% level.

Your batteries are 2 x 104 amp-hour capacity. In theory they will provide 208/20 = 10.4 amps for 20 hours. But in reality you'd only be able to use 50% (or 80%) of that.

Then of course the obvious question is, how do you know what level of charge is in the battery as you are discharging it? The simple answer is, that's a very good question, let me know if you ever find the answer. The LEDs on the panel, a multimeter, a battery monitor gauge or a Smartgauge.

Welcome to motorhoming.

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[Taff Thomas]

Thanks again people, some great advice here!!

 

[Taff Thomas]

Doers anyone have any advice on replacing this?

It's cumbersome and those fuses are a pain.

Is there an "off the shelf" replacement unit I could buy and fit?