Jump Starting Motorhomes - Why not??

[aandncaravan]

We had a Phone call on Tuesday, "Trying to get the Motorhome out of storage, but the Starter battery is flat and there is nothing working in the Habitation area, no lights or any power".

"Once the AA Jump Start it can I bring it over to you?"

 

I suggest that he does not Jump start the vehicle because if both the Habitation and Starter batteries are dead there is a very high chance that the Alternator will be burnt out by the overload.

I suggest that the Starter battery will be past it anyway if its been dead for a while in Storage, so strongly guide the customer to ask the AA man to fit a new battery.

 

I get a phone call about two hours later,

"AA have Jump Started the Motorhome, they said it would be O.K., but now the Ignition warning light won't go out, is that a problem?".

 

I suggest the AA man check the Alternator output for charging.

It wasn't.

 

AA man mutters that he Jump Starts Fiats every day without any issues. To be fair, he offers free recovery to the Fiat specialist just 200 yards from us.

After the Fiat garage fit a £495 Bosch Alternator (the Garage did offer a £120 non genuine item as an option) plus Labour and VAT his Wallet is close to £700 lighter. That is with a discount as he also books a service and MOT with them.

 

The Fiat Garage then drop the Motorhome off to us so we can investigate why nothing works in the habitation area.

 

We find a rubbish habitation battery and the mains 230v charger damaged. It seems that while he was waiting for the AA he thought he would see if the Motorhome Charger would resurrect the Starter battery so plugged in EHU.

 

We replaced the Habitation battery/charger and all is working.

 

Total repair/battery bill for the Alternator and our work won't leave much change out of £1,000.

 

 

If he had just paid out for a new Starter battery at £85.............

 

 

.

 

[RogerThat]

I don't quite understand the bit about the alternator bring burnt out by the overload.

 

The overload of what? The AA's jump starting machine? Or two full on flat batteries trying to pull too much from the alternator?

 

If your guy had plugged and external battery charger in overnight, would this have helped?

[Guest pelmetman]

The AA man doesn't always get it right.......my Fanny had a ongoing stalling problem when in traffic that caused 6 AA call outs.

 

Following advice from the AA after each breakdown.....

 

1st Breakdown..... Replaced the fuel pump....

 

2nd Breakdown.... Dropped and cleaned the fuel tank...

 

3rd Breakdown..... Replaced the fuel lines...

 

4th Breakdown.... My mechanic finally discovered the problem was actually fuel boiling away in the carb *-) .....adjusted the bonnet to improve airflow and fitted a pipe from grill to air intake....

 

5th Breakdown.....Replaced carburetor and air filter......

 

6th Breakdown.....Got the AA man to wire the kenlow fan so it was running all the time......Not broken down since.....So a 3 quid manual override switch could've saved me well over a grand and a world of grief 8-) .....

 

7th Breakdown.....Watch this space :D .....

 

 

[Derek Uzzell]

RogerThat

 

Logically, if a battery-charger could have been used to recharge the vehicle’s starter-battery, jump starting could have been avoided. But the motorhome had been in storage and (presumably) that option was not practicable.

[StuartO]

About two years ago our engine wouldn't start one morning - a sudden, outright failure.  We were on an Aire, no EHU.  I called the breakdown service and, with a struggle to provide enough amps and having to link to his vehicles own batteries because his starter packs wouldn't do it, jump starting eventually worked.  Jump starting a Ducato with a dead starter battery connected takes a lot of umph!

 

It was Sunday morning in France and the garages were all closed the following day for a holiday - but the breakdown guy suggested driving to Auchan in the next town because they stock batteries.  There were two ranges of batteries and I bought the better one.  I also bought a couple of spanners and then went to another Aire before switching off and installing the new battery.  (The UK breakdown service offered to send someone out to do the battery swap but I declined.)  Everything worked after doing this job and we resumed our holiday.

 

Presumably I got away without damage because:

 

a) My starter battery had failed completely (cell failure) and so did not suddenly take a big charge once the engine was running.

 

b) We were not on an EHU - although I cannot see how that would impact on the situation.  Maybe an EHU would have delayed the failure of the starter battery because a float charge would have been applied?

 

Presumably most the the AA man's experience will have been of roadside battery failures, so cell death-type failures?  Surely he would have dealt with some "flat after storage" failures and jump starts too? 

 

Nevertheless the lesson is that if your starter battery has gone flat in storage (rather than suffered sudden cell death on the road) and will therefore demand a high charge immediately the engine starts, don't risk jump starting and overloading the alternator and replace or recharge the starter battery first instead? 

 

And if you are touring and don't want to risk a jump start, you need to persuade the breakdown man to tow you to a place where you can buy a battery.

 

It's worth knowing that big French supermarkets are open on Sunday mornings and they do stock batteries, including heavy duty ones, big enough for a MH.  I bought a correct-sized Fulmen battery (a good make) for 152€, which is a good price.

 

 

 

[lennyhb]

StuartO - 2016-05-14 9:33 AMIt's worth knowing that big French supermarkets are open on Sunday mornings and they do stock batteries, including heavy duty ones, big enough for a MH.  I bought a correct-sized Fulmen battery (a good make) for 152€, which is a good price.

 

 

You were lucky in over 30 years of travelling to & through France I have yet to see a big French supermarket open on a Sunday, occasionally you will find small ones in small towns open for a few hours but they won't sell car batteries.Edit:: There are one or two special days a year when they are open it could have been on one of those days.

[Charles]

So modern vehicles are designed to burn out their alternators if charging a flat battery? How odd, you'd think there would be at least some form of primitive current limiter in series. Perhaps the alternator was on it's way out anyway and the extra work pushed it over the edge.

[Tracker]

We once had total engine battery failure overnight - simple solution - switch it with (one of) the leisure battery(ies) and continue with just one leisure battery in use and sort it out when we got home, or if you only have one leisure battery replace the starter battery asap and continue! But at least you are mobile and in charge of your own destiny!

 

I don't doubt Alan's expertise and experience but I too don't really understand the problem as surely an alternator can only deliver the current it is designed to deliver and if the demand is too great does it not have overload protection of some sort - did it used to be called a regulator or similar back in the days of yore?

 

I have jump started several of my own vans many times over the years as well as sometimes helped others get started on aires as I seem to be one of the few that carries jump leads and I have never known of or experienced any issues?

 

Have I and they all just been lucky or is there something about some (modern???) vans that is too fragile for purpose having been designed with no over engineering or electrical safety margin?

[aandncaravan]

A flat Starter battery will try and draw a big load from the Alternator.

On a Motorhome with up to a 160amp Alternator, most batteries will draw a huge load from the Alternator and fry well before the internal resistance drops and it draws less. So if you jump start a modern Motorhome you will seriously stress the starter battery if you drive it any distance.

If the Motorhome only has a 70amp Alternator you may get away without too much loss of battery life?.

 

If you have 3 flat batteries, Starter and two flat Habitation batteries, in this case on a 110 amp Alternator, they will take a massive load that will take any Alternator to it's limit.

If one of the batteries has also failed internally it can effectively apply a close to 'short' load on the Alternator.

 

As a Wet battery ages the paste may become detached, dropping to the bottom of the Cell and bridging the Plates. This sediment can build up to level where it semi 'shorts' the plates, again this will add to the Alternator load.

Additionally the Alternator takes twice as long to charge up this dying battery. Therefore the overall load of a poor battery on an Alternator may be increased by a factor of four.

Consider that there could be 3 batteries putting the poor Alternator through it's paces and you can see why tired batteries have such a dramatic effect on any Charger, not just the Alternator.

 

If you expose any Charger, not just the Alternator, to this loading clearly the load will be the similar to that on the Alternator. So plugging into EHU, as this gentleman did, will Pop most Leisure vehicle chargers, which remember are primarily Power Supplies that charge batteries. They are not like a Car battery charger which can just shut down if the going gets tough. A Power supply is designed to deliver power when the battery can't, it is up to the user to ensure they are used as designed.

 

You can't easily/cheaply put a safety mechanism on a Power supply as it's prime function is to deliver power no matter what. A Power supply providing the energy for the guidance system on a Cruise Missile, might not be the best design if it decides the going is a bit hard so shuts down? Ok a silly analogy, but shows the difference between a Power supply, so you are not sitting in the dark, and a charger.

 

 

An Alternator regulator controls the voltage, not the current. It is designed to deliver what is asked of it that is how it works. In the above example it would be a bit like putting an Iron bar across the Alternator terminals.

You could put a current limiting device on the unit. This Gentleman moaned about the cost of his Alternator, I am not sure he would be happy paying any more. We are also likely to hear comments about, "why is it so complicated?".

 

 

What may have been the best option in the above case would have been to remove the batteries from the vehicle and charge them one at a time on a Car battery charger.

No scrub, that if they had gone flat for any length of time they should go to recycling.

 

 

Most sudden battery failures, maybe like in Stuarts case, are open circuit. Hence a sudden loss as opposed to a gradual bridging of the plates by sediment. As a result the Alternator isn't asked to supply any charge.

 

 

 

If the Alternator is only 45amps like old 1980's cars/Campers, even flat out it wouldn't stress two batteries as the total charge, after taking out the power used by the Ignition Coil, Petrol pump, fan, lights, etc. might only be 20amps.

I regularly Jump started cars without any issue back then, but 160amps from the new generation of Motorhomes is something else.

 

 

 

 

 

 

[Charles]

Why do they fit these new big alternators?

[Guest pelmetman]

aandncaravan - 2016-05-14 10:45 AM

 

If the Alternator is only 45amps like old 1980's cars/Campers, even flat out it wouldn't stress two batteries as the total charge, after taking out the power used by the Ignition Coil, Petrol pump, fan, lights, etc. might only be 20amps.

I regularly Jump started cars without any issue back then, ***but 160amps from the new generation of Motorhomes is something else.***

 

 

Shall I say it eh? :D.......

 

 

[laimeduck]

Well here I am agreeing with my little star * Tracker - already - who'd have thought?!!

A few years ago I had regular problems with what I now know was a dodgy starter battery on our Benimar. I carried a spare starter battery and regularly jump started the van using jump leads - with no problems. 

I have no idea what alternator I have on my 2003/4 Ducato 2.8 JTD but it worked OK for me.

I eventually replaced the starter battery & have had no further problems but now always carry jump leads. 

Are you now saying I shouldn't in the light of this experience?

[aandncaravan]

laimeduck - 2016-05-14 11:16 AMWell here I am agreeing with my little star * Tracker - already - who'd have thought?!!

A few years ago I had regular problems with what I now know was a dodgy starter battery on our Benimar. I carried a spare starter battery and regularly jump started the van using jump leads - with no problems. 

I have no idea what alternator I have on my 2003/4 Ducato 2.8 JTD but it worked OK for me.

I eventually replaced the starter battery & have had no further problems but now always carry jump leads. 

Are you now saying I shouldn't in the light of this experience?

If you had a low power Alternator (probably 80amp from around that time?) and had a Starter battery that was LOW, not DEAD, and had reasonably charged habitation batteries the scenario would have been very different. Only one of the batteries, the Starter, would have been taking any draw from the Alternator. Each jump start and 'Fast charge' would almost certainly have hastened the end of the battery, which on a later Motorhome with a bigger Alternator would almost certainly have expired a lot more quickly.

[Robinhood]

...of course, the battery might just have been dead in the first place due to alternator problems.......

[aandncaravan]

Robinhood - 2016-05-14 12:14 PM

 

...of course, the battery might just have been dead in the first place due to alternator problems.......[/quote

 

 

It had been in storage for 5 months and the Alternator charge Warning light only lit after the Jump Start, it was fine when first stored away.

[colin]

If the AA man jump started the van without first giving it a good 5 to 10 mins charge he needs a slapping.

I have started my van when it had flat starter and fairly low leisure batteries using my 100amp starter charger with no drama's, you just need to allow time to get a bit of charge into the batteries.

[Tracker]

Does that not make the case for a decent solar panel with split charge to all batteries - unless stored under an opaque roof of course!

[aandncaravan]

Tracker - 2016-05-14 3:46 PM

 

Does that not make the case for a decent solar panel with split charge to all batteries - unless stored under an opaque roof of course!

 

 

Wouldn't that be an expensive solution when you could get away with a quality set of batteries that don't self discharge and a couple of Isolator switches?

A 900amp isolator switch is less than £5, just bolts in place no wiring changes : http://www.ebay.co.uk/itm/Battery-Isolator-Switch-Power-Kill-Cut-Off-On-Off-Switch-Disconnect-Car-Van-01-/111732970085?hash=item1a03cdd265:g:3S8AAOSwhcJWOd~h

 

Unbolt the existing terminal, bolt on the isolator and reattach the existing battery lead to the Isolation switch post. Takes 5 minutes.

Put one on each battery post to allow you to isolate the batteries for any electrical work.

 

With quality low self discharge batteries, like the Varta LFD90, that would see you through 6 months in storage?

 

 

 

 

 

[aandncaravan]

Correction to the above, just been told these battery isolators are available in the smaller Negative Clamp size only, there is not a Positive battery clamp version, but I guess you could modify fairly easily?

 

As the photo shows very easy to fit, not like that traditional Battery isolator where wiring changes are required. Apparently the Green actuator can be completely removed for some anti theft protection?

 

Might not fit battery boxes with limited height?

[colin]

Tracker - 2016-05-14 3:46 PM

 

Does that not make the case for a decent solar panel with split charge to all batteries - unless stored under an opaque roof of course!

 

Funny enough we do have a solar panel, and the van is stored under a 'tin' roof, at first this was 10mx4m and surprisingly the panel would just keep the leisure battery topped up in winter, and stop the vehicle battery getting too low most of the year, but when we added a further 10mx4m of roof to take a second van it became too dark for the panel to put anything into the vehicle battery, hence the problem. Since then have picked up a cheap 40w panel which is fitted to outside of roof and connect this to van when parked up, problem solved.

[Tracker]

Some observations regarding starter battery isolation switches,

a) you need to access the battery under the cab floor on Sevel vans to activate and de-activate it, and that's a faff!

b) if you are parked away from home you will probably need the alarm on?

c) I am unsure what long term starter battery isolation does, or could do, if anything, to the various electronics and memories - and do the door locks still work - albeit I presume by direct key action only?

d) There may or may not be an easy way to fit an isolator as the positive terminal area and connections is a bit congested?

e) The alternative is to ue a negative isolator terminal, or to get some starter or welding cable and extend and fit the switch in a more accessible location?

 

So I have not bothered with the engine battery isolation as yet!

 

But I have fitted a heaavy duty isolator in an accessible place for the leisure batteries and they now last for months rather than weeks when not in use with no apparent ill effects on the habitation electronics.

[Archiesgrandad]

A quick note for Pelmetman, it would be worthwhile linking up with the Reliant Scimiter and Sabre Owners club, those cars used the same power unit, and I suffered most of the problems that you've had on my Scimiter.

On the subject of French supermarkets, I think you will find that a lot of them now open on Sunday mornings. We have a Carrefore and an Intermarche in our little one horse town, ( 2200 residents) and both have started opening on Sundays, and they both stock an amazing range of things.

One final point, why do we all allow them to sell us these expensive motorhomes based on the worst base vehicle available?, and is it my imagination or are the latest ones even worse than the old ones?

AGD

[starvin marvin]

Interesting thread. My experience is a flat starter battery on Marine Parade Dover after driving up from Spain in 3 days in Fiat 2.8 tdi. RAC jump started it, drove back up to East mids and parked on our drive. Next day, same again, except RAC man's leads not long enough to reach, so we pushed it onto the road and did a towed bump start....oh the joy. Drove straight to my battery bloke for a new battery.

[Geeco]

I used the "5P" option "prior planning prevents poor performance" and specified my AT with a factory solar panel. If you do not turn the major isolation switch off the solar will keep both the vehicle & habitation batteries charged when parked up. My AT is left parked up an open hard stand and as there is sun most days the batteries are fully charged every check I make. The cost of the solar panel is definitely worth it for the convenience of always having a full charge. Cheers,

[Derek Uzzell]

lennyhb - 2016-05-14 10:10 AM

StuartO - 2016-05-14 9:33 AMIt's worth knowing that big French supermarkets are open on Sunday mornings and they do stock batteries, including heavy duty ones, big enough for a MH.  I bought a correct-sized Fulmen battery (a good make) for 152€, which is a good price.

 

 

You were lucky in over 30 years of travelling to & through France I have yet to see a big French supermarket open on a Sunday, occasionally you will find small ones in small towns open for a few hours but they won't sell car batteries.Edit:: There are one or two special days a year when they are open it could have been on one of those days.

As Stuart says, supermarket Sunday-morning-opening is relatively common in France nowadays. This link confirmshttp://commerces.com/supermarche-ouvert-le-dimanche.html