Charging Engine Battery From Mains Hookup

[alistair]

Our 1998 Duetto spends 9 months a year in storage where there is no mains power supply nearby for trickle charging. As I live 12,000 miles away, occasional visits for battery charging aren't possible. Last year, the battery died in storage and we had to use jumper leads to get the van started for its 400 metre drive to the camping ground pitch where we had mains hookup. I have wondered since about connecting the engine and leisure battery positive terminals with a length of wire (fitted with an in-line fuse) on this first night so the van's mains charger could charge both the engine and leisure batteries overnight and give us a chance of starting it next morning. I know that current-sharing between the two batteries may be an issue, and I don't know if the van's charger would handle the two batteries connected in parallel. I presume from the charger's point of view it would just see a voltage source and wouldn't care that it was two batteries rather than one, but I would appreciate any comments from anyone who knows about such things and/or have tried this arrangement.

 

Thanks.

 

Alistair

[BGD]

Remove engine battery from van when laid up.

 

Attach battery to trickle charger/maintainer plugged in to any mains power point.

 

Re-install battery upon return.

 

 

 

 

 

[spospe]

A small solar panel would be a simple solution to keeping the batteries topped-up (assuming that they are in good condition and fully charged to start with).

 

The latest Duetto on the MK7 Transit does have a selector switch, so that the output of the 12-volt charger can be directed to either the engine or the leisure battery. From memory (we used to have a Duetto on the MK5 Tranny), the Zig control panel cannot do this without the addition of another switch somewhere. If you do go down the route of joining the batteries together, do so via a fuse of say 20 amps rating.

 

I do not think that you would harm the 12-volt power unit by linking the batteries in this manner.

 

[spartan3956]

Why dont you get a 12 volt charger and connect it directly to the vehicle battery from the mains hook up.

I have done this by fitting a 12volt socket connected to the battery it has a 10 amp in line fuse so its a live source. very useful.

Fitted a cigarette lighter plug to the 12 leads of the charger 4amp so you can connect the charger to the mains from internal 230v sockets.

That would charge the vehicle battery overnight.

I actually have electricity while parked i use a motorcycle charger all the time so it keeps the battery topped up.

I do this with the liesure batteries as well as they are much cheaper to replace than the internal zig charger, which have a tendancy to boil the batteries over time as they do not float the battery current very well when fully charged.

Those small solar panels are not brilliant i checked one in bright sunlight and it gave out 1/2 amp so winter time would probably just cover the alarm usage. you would have to go for a bigger one on the roof to get decent current.

As for the wire connecting both batteries.

The charger will always charge to the weakest battery so that both batteries will be the same it it will will not continue charging when the one is full possibly leaving the one battery below full charge but that is not an issue in you situation a hand held volt meter would help you check the state of charge of both batteries.

I wouldnt use the wire method as a matter of course i would go the charger route it safer.

[Brian Kirby]

Dearly beloved, you are not reading the guy's question.  His van is in storage, where there is no hook-up available.  Reset?  :-D

[PJay]

alistair - 2010-04-28 11:14 PM

Presumably you pay to store your van? Could you not arrange for the battery to be charged occasionally?

PJay

 

Our 1998 Duetto spends 9 months a year in storage where there is no mains power supply nearby for trickle charging. As I live 12,000 miles away, occasional visits for battery charging aren't possible. Last year, the battery died in storage and we had to use jumper leads to get the van started for its 400 metre drive to the camping ground pitch where we had mains hookup. I have wondered since about connecting the engine and leisure battery positive terminals with a length of wire (fitted with an in-line fuse) on this first night so the van's mains charger could charge both the engine and leisure batteries overnight and give us a chance of starting it next morning. I know that current-sharing between the two batteries may be an issue, and I don't know if the van's charger would handle the two batteries connected in parallel. I presume from the charger's point of view it would just see a voltage source and wouldn't care that it was two batteries rather than one, but I would appreciate any comments from anyone who knows about such things and/or have tried this arrangement.

 

Thanks.

 

Alistair

[Brian Kirby]

I think that if either battery is left without charge for 9 months it will end up flat, no matter how fully charged it was when left.  Batteries that are allowed to become flat, and are left flat, will suffer permanent damage.  Since there is no charge facility at the storage compound it seems a solar panel will be the best option, assuming the van is not being stored under cover.  However, what the solar charging regime should be, I do not know. 

We leave ours on mains charge at home, and the charged is supposed to allow the battery charge to fall to somewhere around 11V, and then cut in to bring it back to full level, so that it is not on a continual trickle rate.  Presumably a solar charger that does something similar would be the best option for your circumstances.  Tracker, Brambles, Spospe or Clive seem the battery/charging whizz kids here but, as none has yet popped up, I guess they are all elsewhere at present.  Maybe at the weekend?

[Guest Tracker]

I am indeed flattered by Brian's description of me as an expert! Unfortunately it is not quite true as I have no academic knowledge about anything at all - but I do have a life time's experience of Professor Sodde's Law and the way it continues to affect my life!

 

I too would suggest a solar panel with regulator and I would have thought that a smallish panel of about 30 to 60 watts should be enough to keep the battery(ies) happy?

 

A solar regulator with twin outputs would be my suggestion - one to leisure battery and one to engine battery and if you Google 'solar panels' or solar panel regulators' lots of info will become available.

 

Fitting and wiring up is pretty straightforward - but I guess not if you are out of the country - although it can be time consuming - especially getting cables on the convoluted route from regulator to engine battery.

 

Have a good read and then if there are specific questions - almost bound to be unless you have Brambles or Clive's background - ask again.

[Guest peter]

Buy a new engine battery each year, about £60'ish. Much cheaer than a solar panel. Or if you know anybody near your stoage site, take it off the van and ask them to keep it charged for you. As for charging on hook up, plug a charger into one of the vans 13 Amp sockets and connct it directly to the engine battery.

[Brambles]

If you use good quality Calciium Technology batteries and fully charge and then disconnect them they should last 9 months with enough oomph left to start the engine. Good bramds such as Bosch, Exide (not for leisure battery), Varta or Delphi.

For the leisure battery there are not many choices for very low self discharge and Varta Calcium Leisure is what I would recommend.

If you are doubtful then a very small solar panel, 10 to 20 watts would suffice and could be left permanently connected to the batteries, and placed on the dashboard or immediately under a clear roof light.

A high quality gel battery can also safely be stored for 9 months if fully charged but are very expensive. When I say fully charged, I mean fully charged - either using somethng like a Ctek charger or a trickle maintenance charger left on for a few days to really top up the charge.

 

Jon

[Brambles]

peter - 2010-04-30 10:24 PM

 

Buy a new engine battery each year, about £60'ish. Much cheaer than a solar panel. Or if you know anybody near your stoage site, take it off the van and ask them to keep it charged for you. As for charging on hook up, plug a charger into one of the vans 13 Amp sockets and connct it directly to the engine battery.

It is not just the engine battery which will flatten if left connected, its the leisure batteries as well as usualy there is somethin drawing a few mAmps like 30 mamps or more standby power like electronic control for truma boiler and the main control panel.

ather expensive to replace 3 batteries, but as budget brands batteries and non calcium/calcium will not last much more than 3 to 6 months.

Gel batteries and AGM also generally have very low self discharge and lower sulphation rates with low voltage.

[alistair]

Many thanks to all who have taken the trouble to comment. I could have saved some of you a few keystrokes if I'd mentioned that the storage is under cover, but in a shed with a lot of large gaps between walls and roof (for ventilation, not because it's falling down!) so there's a view of the sky at an angle - perhaps enough to get something out of a solar panel.

[Brambles]

Afraid through the gaps you would not get enough light. You would have to mount the panel remotely on roof of shed or whatever. If the shed is secure, how about buying a cheap portable gemnerator, the ghastly 2 stroke ones which generate about 800 watts. Someone could then maybe visit every 3 months and run the generator for a few hours.

 

Look chaps - finally found a good reason for owning a geny!!!! (lol)

[Guest Tracker]

Is there perhaps a friend or relative living near where the van is stored who could call in say once every two or three months that you are not in the UK and just run the engine for five minutes for you?

 

Failing that, would it be possible to store the van nearer where someone you trust lives to enable that to happen, as this would seem to be the easiest and cheapest method of battery charging?

[Brian Kirby]

Alistair

Were you in Pompeii in Spring 2006, by any chance, camping Spartacus?  I met a New Zealander at that site, who was doing (from memory) exactly what you do.

It sounds as though your best bet re the batteries will be to disconnect both when you depart, charging both fully via a Ctek, or similar, charger overnight on your last night, and again on your first night back in UK. 

Question for Jon et al, if this is done while the van is being used (as I assume it must be), would simultaneous consumption of 12V power (lights, pump etc) overload a Ctek while it is charging?  Should Alistair disconnect the batteries, leaving only the charger connected to them and, if he did, would the fitted on-board transformer/charger then cope with loads without the leisure battery connected as "ballast"?.

[Brambles]

No Brian it would not overload the charger, it will just current limit to its max and possibly get a bit confused as well. Ideally have nothing switched on when charging and better still disconnect any loads and just leave the charger on. For the final topping up maintentance stage it will only be supplying 50 to 100 mamps so any load is going to prevent the full charge.

[Brian Kirby]

Thanks Jon.  So Alistair should just connect the Ctek before going to bed on his last night, leaving all his 12V stuff switched off/disconnected, and his batteries should then spring back into life nine months later when he returns.  Sounds a good result for the price of one Ctek charger.

[Brambles]

Something like that, as long as quality calcium batteries (maintenance free) are used. It is also possible (very likely) the onboard charger depending on type will do the same job, so let it take care of the liesure batteries and use the Ctek to charge the engine battery. The amount taken in morning to start the engine is very small. Disconnect the leisure before setting off (remove only negative lead for safety) then store vehicle and disconnect engine battery (again negative lead).

 

 

 

[Patricia]

When I leave my car in France I disconnect the leads from the battery and so far (keeping fingers crossed) all is well after 6 - 9 months through severe winters every year. Now I've done it - this year Tracker's law will come into operation.

 

Brian I hate to correct you but Spospe had already answered Alistair.

[alistair]

Thanks again to all. The idea of using an external charger on the last night is interesting and one I'll look into. I’m interested in the comments re calcium batteries – I had never heard of them, but I now understand that sealed gel batteries have calcium in their plates. I’ve read various comments on gel batteries, many saying they aren’t worth the expense, but if they would have a better chance of holding up over 9 months they could be worthwhile.

 

Brian: No, it wasn't us in 2006. We started our UK/European adventures in the Duetto in 2007. Kiwis pop up everywhere! This year we'll be mainly in France, homing in on Ecommoy to attend the Le Mans Classic motorsport event in July before moving on, probably to the Ardeche.

 

[Guest peter]

Tracker - 2010-05-01 11:53 AM

 

Is there perhaps a friend or relative living near where the van is stored who could call in say once every two or three months that you are not in the UK and just run the engine for five minutes for you?

 

Failing that, would it be possible to store the van nearer where someone you trust lives to enable that to happen, as this would seem to be the easiest and cheapest method of battery charging?

Keep up Richard. I already suggested that. See above. *-)

[Brambles]

"I’ve read various comments on gel batteries, many saying they aren’t worth the expense, but if they would have a better chance of holding up over 9 months they could be worthwhile. "

 

Alistair, you have heard of Calcium batteries, you just do not realise you have.

 

Yes, Gel are certainly using Calcium in the plates.

 

Flooded Wet acid Batteries....

Most Batteries termed low maintenance have lead-antimony plates.

They have a charge voltage of 14.4 volts. They have low water consumption but self disharge about 1 to 2% a day. Plates hardened with Antimony have a very long service life if kept charged and not allowed to sulphate through low voltage.

 

Maintenance free Batteries which most starter batteries are now or at least have been for the last couple of decades have lead calcium plates.

They have a charge voltage of about 14.6 volts. They have extremely low water consumption and self discharge less than 1 to 2% a week. They tend to shed more lead from the positive plate. There is a reseve of acid above and below the plates. A gap is needed below the plates as shredded lead will eventually short out the plates.

 

 

Calcium Calcium batteries are becoming more popular and common as they cope with cycling better and deep discharging which is needed on many modern vehicles with high standby power drain of so much electronics on board left in standby mode, car alarms etc.

They have a charge voltage of 14.8 volts and extremely low water consumption but most of the low comsumption is due to never gassing as charge voltage is slightly higher and an alternator is 14.4volts so never really fully charged. The chances are your starter battery is Calcium Calcium or other wise known as a Calcium Battery. Self discharge is around 1 to 2% a month. they shred much less lead, and when they do th elead is a compound wih the calcium and is insulating, so a gap is not needed below the plates allowing a much larger reserve of acid above. Acid below th eplates rarely gets mixed, acid above does so is a better construction for long life.

 

Be aware though these self discharges all increase as a battery ages and also dependant on temperature. Best below 10 deg C.

 

Manufactures also use lots of other exotic materials in the plates to improve the performance of the batteries, Silver being very common but tin, selenium , a**enic and loads of others like carbon (does not actually achieve very much but sounded good 20 years ago and after a short time all dissolved into the acid anyway).

The biggest factor though in improving batteries is the quality and purity of the lead, and design of the plates and seperator envelopes. There are now a lot more technologies used and all gets rather complex with charge voltages etc......but they are still basically lead acid batteries.

 

Leisure batteries are a variaton on starter batteries in they have thicker and fewer plates and designed to cope with deep disharging better. They cannot supply the high currents required for a starter motor but have much improved deep discharge characteristics. There are also some termed Hybrid or Marine batteries where they can do both. To get a good battery for deep dicharging you ideally need a Calcium Calcium battery which will allow up to 80% depth of discharge although Varta have a range of Leisure they call hybrid technology (as well as their Calcium technology) and are good to 60% dod, and have a large cycle life.

 

Gel batteries or AGM have a requirement gassing is reduced to almost NIL gassing possible as the gas bubbles cannot escape the gel or Mat.

This is achieved in two ways, 1st using Calcium for both plates so charge voltage is increased and is safe on a 14.4 volt alternator. Next is to seal the battery with a safety pressure vent. These are called VRLA batteries. (Valve regulated Lead Acid) and operate under sight pressure which helps stop the formation of gas bubbles. Gel and AGM batteries cost a lot more for quality ones although AGM are a lot cheaper than they used to be.

Gel and AGM have extremely low self discharge, but same as others as they age the self disharge rate rises.

 

I would expect you to get over 3 years from a starter battery (or Leisure if well looked after) before self disharge started to give you problems over 9 months. After 3 years there would be a high risk it would no longer hold its charge sufficiently.

 

Oh jeepers just read all I have written, cannot believe I have wriitten so much crud - Ah well, will leave rather than condensing and post anyway. Sorry for any spelling mistakes etc.

[Guest Tracker]

peter - 2010-05-01 11:49 PM

Keep up Richard. I already suggested that. See above. *-)

 

I am indeed indebted to my learned fiend for drawing to my attention my human fallibility of failing to read his earlier posting.

 

In my defence I can only add that as most of his postings are of limited value I tend not to read them!

 

I rest my case my lords.

 

You gotta smile ain'tcha - sorry Pete!

[Brambles]

My gawd! are you two still fighting - I shall get a couple of used leisure batteries and clap them around your ears if you do not start being nice to each other.

 

(its alright, I know it is just harmless banter you two have and love each other really) :-D

[Guest Tracker]

How could you not like an amiable old duffer like Peter who drives arouind in an old MGF the same colour as his shirt!

 

PS I already have two suitable old leisure batteries - just in case!