Recharging the Battery - Dumb Question From a Newbie!

[HKF]

The battery on my MoHo is flat (I guess the solar panel isn't picking up enough light?). Anyway, I need to put some charge in it so that the automatic drain of the boiler works if the temperature drops too low. Do I just plug the extension cable into the MoHo and my house? Is that how it charges, please? Sorry for being so dumb but this is all new to me and I don't understand electrics at all. Thank you.

 

[Richard n Ann]

The battery on my MoHo is flat (I guess the solar panel isn't picking up enough light?). Anyway, I need to put some charge in it so that the automatic drain of the boiler works if the temperature drops too low. Do I just plug the extension cable into the MoHo and my house? Is that how it charges, please? Sorry for being so dumb but this is all new to me and I don't understand electrics at all. Thank you.

Yes that's how ours is. If it's charging you should see the voltage go up above 13v

 

[pappajohn]

Maybe set it on a plug-in timer to prevent overcharging depending on charger type....some keep charging even when fully charged and can damage the battery.
A couple of hours once a week should be enough.

 

[tonka]

Small addition... On some vans the charger can be switched on /off so once hooked up look for an indication like a light that charger is active.
Not familiar with your van so unsure..

 

[Jev88]

Once plugged in you need a simple multimeter. Measure voltage DC across the battery and if it is over 13v then you have charge going to that battery. Note what Pappa says though, no point leaving switched on all the time if you don't know what type of onboard charger your van has.

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[HKF]

Thank you so much to everyone who answered. I'm very, very grateful for your help

 

[prb]

Are you sure your boiler drain needs 12v? Mine doesn't.
(Edit) Just seen this earlier thread:

Truma automatic dump valve question with a twist

The twist is that when opened only about a litre of water drains out. Tend to go away for a few days every other week and at this time of year drain down between trips. First noticed when on refilling the system came up to pressure in seconds rather than the wait for filling the boiler, a Truma...

www.motorhomefun.co.uk

 

[Conrad J]

Which battery is flat? The engine battery may well not get charged from the solar panel. Even in winter there should be enough light to keep your leisure battery topped up, but as suggested, a quick test with a multi tester will show. Remember, if a battery drops too low it may die completely. If you can easily keep the 'van plugged into the mains, that'll take extra care of the leisure, and you could get a trickle charger (plug into a socket in the 'van) that'll keep the engine battery topped up. Hope this helps. BTW, the only dumb question is the one you don't ask.

 

[HKF]

Which battery is flat? The engine battery may well not get charged from the solar panel. Even in winter there should be enough light to keep your leisure battery topped up, but as suggested, a quick test with a multi tester will show. Remember, if a battery drops too low it may die completely. If you can easily keep the 'van plugged into the mains, that'll take extra care of the leisure, and you could get a trickle charger (plug into a socket in the 'van) that'll keep the engine battery topped up. Hope this helps. BTW, the only dumb question is the one you don't ask.

I don't know about the engine battery but the leisure battery is / was flat. I've had the cable plugged into the house electrics today and will check it tomorrow to see if it's charged. I didn't know a battery could die after going flat I hope it hasn't. It's parked with trees between it and any amount of sun we might get, so it doesn't get much light on the solar panel. Where do I get a mutli tester from, please (I live in France), and what do I do with it? I don't even know where the leisure battery is

 

[Conrad J]

Can’t help with where to buy a multi tester is France, must be an equivalent to screwfix, etc. It’ll have a setting to check voltage, you’re looking for 12 plus. No handbook to tell you where leisure battery is? Often under front passenger seat in many vans.

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[BouncyBoatFolk]

I don't know about the engine battery but the leisure battery is / was flat. I've had the cable plugged into the house electrics today and will check it tomorrow to see if it's charged. I didn't know a battery could die after going flat I hope it hasn't. It's parked with trees between it and any amount of sun we might get, so it doesn't get much light on the solar panel. Where do I get a mutli tester from, please (I live in France), and what do I do with it? I don't even know where the leisure battery is

A wander along to Mr Bricolage might prove fruitful.
Or magasin de bricolage
Mike.

 

[Potty]

Posted in error

 

[BouncyBoatFolk]

Under drivers seat in ours, passenger seat has the brains of the outfit sitting in the seat, and the brains of the van sitting under it!!! She made me type that .
Mike

 

[autorouter]

Anyway, I need to put some charge in it so that the automatic drain of the boiler works if the temperature drops too low.

If it's the electrical type of frost protection valve, it will spring open if 12V power is lost, so it's fail-safe. It needs 12V power to keep it closed. It also springs open if the temperature drops too low, if there's 12V power.

Another big DIY store chain is Leroy Merlin, but look for anything with 'Bricolage' or 'Brico' in its name - Bricomat, Bricomarche for example.

 

[The Old Man]

Are you sure your boiler drain needs 12v? Mine doesn't.
(Edit) Just seen this earlier thread:

Truma automatic dump valve question with a twist

The twist is that when opened only about a litre of water drains out. Tend to go away for a few days every other week and at this time of year drain down between trips. First noticed when on refilling the system came up to pressure in seconds rather than the wait for filling the boiler, a Truma...

www.motorhomefun.co.uk

As a result of a recent experience I was told that my boiler drain needs 12v.

But it need 12v to keep it closed!

If the temperature drops the valve opens mechanically.

If the 12v power drops, removed in my case, the valve opens and dumps the boiler contents.

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[autorouter]

Do I just plug the extension cable into the MoHo and my house? Is that how it charges, please?

There will be a built-in mains battery charger. It is usually built into the 12V distribution/fusebox, but sometimes it is a separate box. Some of these chargers have a switch to allow you to switch it on and off, but many don't have a switch, they come on automatically whenever you plug in to the hookup post. It depends on the make/model of the distribution box. If you tell us the make/model, or post a photo, someone will recognise it.

There will always be a way to charge the leisure battery, but not all MHs have a way to charge the starter battery. If there is a voltage display, you can tell if the battery is charging. A voltage below 13.0V means it's not being charged. Above 13.0V, up to 14.8V, means it's charging. Most chargers go up to about 14.5V for severalhours, then settle downto about 13.5V when the battery is fully charged.

If there's no voltage display on the panel, a cheap multimeter from a DIY store will give you the same information.

 

[The Old Man]

To charge the engine battery I have, when on EHU, plugged a standad ca battery charger into a 240 socket inside the van, passed the thin 12v leads out of the door and closing the door on them, opening the bonnet and connecting the small clips to the battery terminals, used some stray foam or bubblepack to protect the wires and closing the bonnet.

Switch on the 240v socket and sit back.

 

[HKF]

I still need help....but BIG thankyous to everyone so far! My husband is ill at the moment, bed-bound and unable to help me, which is why I'm asking these dumb questions! I'm learning as I go along, though Here's where I'm at now....

The leisure battery is now fully charged I've opened all the taps (kitchen, bathroom sink and shower) and manually emptied the fresh water and grey water. However, I'm still a bit confused reading the above replies as to whether or not the boiler will have already emptied itself. The temperature has been down as low as 1 degree over the last week, and obvously even colder in the wind chill (we live in a very exposed area and the MoHo is open to the northerly wind). I guess the boiler will have some amount of protection but I don't know if it will have already emptied. If it might not have, and I need power for it to do so when it's necessary, do I need to leave the control panel on, please? Also, is there anything else I need to do to protect the MoHo from damage, please? Thank you so much!!

 

[The Old Man]

I would home that the boiler has automatically drained but, on my boiler/heater the drain 'button' is at the front of the cupboard with a red top.

I push it down to dump and pull it up to fill.

I'm sure there are probably a dozen different designs though.

You may need a torch to find it. If a different design it will probably be a simple design.

A tip I was given when I started was to keep a clothes peg to hand.

With the design of my dump button, clipping the clothes peg around the button will stop it dropping and dumping.

So if you are preparing the van for a trip and it is cold, use the peg to force the valve to close. This will let you fill the fresh water tank and pump supplies into the boiler. Then you can run the boiler to heat the water, and the boiler cupboard and when you remove the peg the water will not be dumped.

Hopefully once the engine is running and the cab heater raises the temperature the safety valve will stay closed.

DO REMEMBER TO REMOVE THE PEG!!!!!

 

[The Old Man]

No power required to trigger the safety valve.

During the winter I try to take the van for a 40/50 mile drive once a week, preferably on a dry day and leave some windows open so as to;

Push a little charge into the batteries.
Exercise and flex the tyres.
Stir the engine fluids.
Blow the water off the roof.

Also do check that you haven't left any food in the van.

I believe many will remove all the bedding and keep it at home.

Turn the wiper blades around, or put some old socks over them. It stops them freezing to the windscreen.

Open all sink, shower taps so that water can drain from the feed pipes. NB make sure that the water pump is switched off.

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[The Old Man]

PS. Dont forget to empty the fridge and leave the door open.

Otherwise mould will grow quickly.

 

[Marauder]

I buy everything except food from eBay. Once I realised that most items will drop through my letter box next day, I stopped going to the shops at all. Food is also delivered: MAJOR convenience (and no covid!).
Instructions for Multimeter will be included if you buy a brand you recognise. (VERY easy to use)

Leisure battery will be somewhere accessible, mine is under seat adjacent to hab door.

Also, I have a handy little device (eBay again) which plugs into the cig. lighter socket. It has USB charge point, but also a digital display showing starter battery voltage. I have a couple of these, and they DO show slightly different voltages in the same cirumstances, but still very useful to show difference in charge rate when resting, or when engine is running etc.

A battery which has been COMPLETELY (won't even light a bulb) flat is useless. A Batt which has been down to 50% charge is assumed to be seriously damaged. To test, charge to full capacity, (measure voltage) then disconnect from everything and leave for at least 24 preferably 48 hours, then measure voltage again. There should not be any loss.

Or use MHF search facility to learn more about this topic. The MHF weekly roundup in last week or so, had an IN DEPTH discussion of this full of numbers that will make your head hurt (as with everything else to do with Motorhomes!).

LennyHB posted link to a useful chart of Batt charge levels in that thread.

Good Luck

Steve

 

[TheBig1]

I don't wish to appear patronising and wish you were local so I could help.

Drain ALL the water, including the boiler, or it has a tendency to split if it freezes leaving a stupid expensive bill. Drain the tanks, then turn off both taps in bathroom and kitchen. Turn off the pump and close the boiler drain when it stops running. Open one tap on the kitchen set to cold, remove the shower head from its hose and leave to drain in the sink. Turn the shower tap on and set to cold. Then blow hard down the shower hose. Water will be ejected in the kitchen sink. Switch to hot water on both kitchen and shower and repeat. Then repeat again for the shower sink. And flush the toilet to release any water in the valve

Inside, open all cupboards and lift seat bases and prop open for ventilation to stop condensation. Outside, lift the wipers from the glass and cover to protect them. If in a very exposed area which gets very cold, lift the bonnet, and cover the engine with an old coat to prevent damage. If you do this, you absolutely must remember to remove it before trying to start the engine. Once a month, take the van for a drive if you can, to keep everything from seizing up. The engine needs to be worked, not just run on the driveway for half an hour, to circulate the oil and lubricate seals

Put chocks in front of and behind the wheels and then let the handbrake off to stop it rusting the shoes to the drums

 

[autorouter]

Where do I get a mutli tester from, please (I live in France), and what do I do with it?

A multimeter can be used to measure the battery voltage. How to use it? Youtube is your friend, but here's the basics.

You'd think a multimeter would have clearly marked 'positive' and 'negative' sockets to plug the test leads in, but no such luck.

Plug the black lead into the 'COM' socket, that's the negative. Plug the red lead into the socket with 'V' in the label, that's the positive.

Set the meter to the 20V DC range. DC is shown by a symbol of a solid line above a dotted line. AC is shown by a wavy twiddle symbol. Batteries are DC.

Push the black test lead probe onto the leisure battery negative terminal post. Push the red test lead probe onto the leisure battery positive terminal post. You should get a reading of 10 to 15 volts. If you get the probes the wrong way round, all that happens is a minus sign appears in front of the voltage reading.

 

[HKF]

Thank you again to everyone for all your help and instructions. I really appreciate everything. Our MoHo is our first one and we only bought it in August this year. After only two short trips out, everything is still very new and I worry about doing things wrong! I'll be out again tomorrow making good use of your suggestions. Thank you so much

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[steve69]

This "12V needed to protect the boiler from frost" bit mystifies me. Surely if the battery is constantly protecting the boiler during overwintering, then of course it will "go flat" . It might explain why quite a few motorhome leisure batteries drain after a few days of standing. Mine does, perhaps this explains it. I have decided to completely disconnect the leisure battery whilst fully charged and overwintering. I assume it should be fine.

 

[autorouter]

This "12V needed to protect the boiler from frost" bit mystifies me.

The older version of the Truma frost protection valve needs a 12V supply to stop it from springing open. It's an extremely small current requirement. If 12V is lost, the valve opens and the water heater drains. So in that sense it doesn't need 12V to protect the heater, it needs the 12V to keep the heater full of water. Later versions of the valve don't need 12V, they are mechanical.

 

[Marauder]

Mine does, perhaps this explains it. I have decided to completely disconnect the leisure battery whilst fully charged and overwintering. I assume it should be fine.

Another explanation could be that the battery is faulty. A healthy batt should last way more than 'a few days'. Even if you disconnect yours, you should keep it in some sort of charging regime to keep it topped up. Might be worth checking it's age and condition.

 

[steve69]

Another explanation could be that the battery is faulty. A healthy batt should last way more than 'a few days'. Even if you disconnect yours, you should keep it in some sort of charging regime to keep it topped up. Might be worth checking it's age and condition.

6 weeks disconnected and still fully charged. No, there's something in the system that drains the battery within a few days. Ditto the previous leisure battery.. And this is with all main switches off....The van is 10 years old now but i believe it has always been like this. I have heard that some other vans do the same thing.

 

[scally]

To charge the engine battery I have, when on EHU, plugged a standad ca battery charger into a 240 socket inside the van, passed the thin 12v leads out of the door and closing the door on them, opening the bonnet and connecting the small clips to the battery terminals, used some stray foam or bubblepack to protect the wires and closing the bonnet.

Switch on the 240v socket and sit back.

Seems a complicated way, on mine I've fitted a split charge relay with override. So when on electric hookup I just override the relay and the onboard charger does both

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