Motorhome Vehicle Battery Charge

[martincath]

Hi all
I am new member, thanks for letting us join. Recently bought a new Fiat swift escape. I had a Phantom alarm fitted for insurance purposes so can see the voltage of my vehicle battery on my phone and was alarmed to see it going down to 11.9 volts over a 2 week period. I have contacted my supplying dealer and they say with the technology on the new Fiats the batteries are flat after about 3 weeks if not used. I store under cover so the solar panel is not producing any charge, no access to mains either. I can't take the battery off every few weeks to charge it as it make my insurance invalid so have come up with the idea of having a slave battery connected to the van battery so that I can take it away and charge it when the voltage gets low and then it will equalise the two batteries when reconnected and put power into the van battery. Is this a good plan or what are the pitfalls and any other ideas??
Thanks

 

[poppycamper]

Hi all
I am new member, thanks for letting us join. Recently bought a new Fiat swift escape. I had a Phantom alarm fitted for insurance purposes so can see the voltage of my vehicle battery on my phone and was alarmed to see it going down to 11.9 volts over a 2 week period. I have contacted my supplying dealer and they say with the technology on the new Fiats the batteries are flat after about 3 weeks if not used. I store under cover so the solar panel is not producing any charge, no access to mains either. I can't take the battery off every few weeks to charge it as it make my insurance invalid so have come up with the idea of having a slave battery connected to the van battery so that I can take it away and charge it when the voltage gets low and then it will equalise the two batteries when reconnected and put power into the van battery. Is this a good plan or what are the pitfalls and any other ideas??
Thanks

What sort of leisure battery's do you have?
Just a thought, would a Battery Master fitted work.
Sorry not finished typing... that would prolong the charge in your vehicle battery and if still in storage when getting near flat, you could remove leisure battery and recharge it...
Possibly one solution.

 

[Vansflyer]

This Jobbie here may work for you with the extra BT module. https://www.wildebus.com/product/ablemail-amt-12-battery-maintainer/
Through the app you can control what voltage your leisure battery will drop to whilst "charging" the engine battery. You can also set what voltage the cab battery drops to before it gets charged off the leisure battery.
EG: When cab battery drops to 12.4V the leisure battery will charge till it gets to 12.85v and then stop. Leisure battery won't charge the Cab battery if it's voltage drops below 12.2V.
So a fully charged leisure battery can do a LOT of trickle charging to the cab battery over several if not many weeks whilst the van is in storage.
The tracker / alarm drain should also be less than about 80ma so maybe something else in the van is pulling it down? Worth using a clamp multimeter if you know what you are doing with one to see if you have any other parasite drain on the cab battery. And is the cab battery "healthy"?
The Ablemail stuff is very good and pretty much all options are covered.

AMT12-2 Trickle Charger charges Vehicle Battery from Leisure Battery with Solar Charger /Mains Hookup | Ablemail Electronics

The AMT12-2 has many names Trickle Charger, Battery Maintainer, Battery Saver, Reverse Charger, Top Up Charger, Battery Equaliser, but its purpose is to keep a Source / Vehicle Battery charged & protected from damage during prolonged periods of Vehicle, Boat & Motorhome inactivity or storage...

www.ablemail.co.uk

 

[martincath]

Hi
That sounds like a good option, I was going for the extra battery option as I was concerned about getting at either battery to take home and charge. I think the leisure battery is only a 85 amp one fitted as standard. the vehicle battery seems to start at about 12.6 volts and go down from there, should it be reading higher than that when I first park it up?

 

[Lenny HB]

the vehicle battery seems to start at about 12.6 volts and go down from there, should it be reading higher than that when I first park it up?

With smart alternators they often only charge to 80% which is not good for a LA battery.

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[Vansflyer]

Hi
That sounds like a good option, I was going for the extra battery option as I was concerned about getting at either battery to take home and charge. I think the leisure battery is only a 85 amp one fitted as standard. the vehicle battery seems to start at about 12.6 volts and go down from there, should it be reading higher than that when I first park it up?

From memory when a cab battery is charged and "at rest" it should be about 12.5-12.7v
85ah lead / gel battery should be good for 50% discharge without issue so 40ah is a fair bit of top up. Maybe add a battery or change to lithium if in storage for a very long time with the added benefit of more power when on site?

 

[martincath]

Thanks for all the information, that is very informative, I had better pay my dues now and become a fully paid up member

 

[pappajohn]

Instead of charging a second battery and connecting to the existing battery you could charge the second battery at home the swap for the battery on the van and take that home to charge.
You'd probably only need to do it every 10 days to two weeks.

 

[pappajohn]

From memory when a cab battery is charged and "at rest" it should be about 12.5-12.7v
85ah lead / gel battery should be good for 50% discharge without issue so 40ah is a fair bit of top up. Maybe add a battery or change to lithium if in storage for a very long time with the added benefit of more power when on site?

Problem.......how can you fit a second starter battery where there's no room for a second.
fit a lithium.......and a lithium alternator !!!!

 

[Vansflyer]

Problem.......how can you fit a second starter battery where there's no room for a second.
fit a lithium.......and a lithium alternator !!!!

A second leisure battery not another cab battery, sorry I wasn't clear about that. With the Ablemail unit you can configure all kinds of parameters to suit the battery type and how discharged you want them to be. Obvs a lithium is happy going to an extended discharge of 90% or so vs 50% of lead acid versions. You generally don't need to change the alternator when fitting lithium but a B2B is always a good idea for max charging on a lithium is the common thinking.

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[eddie]

Buy a MHF Battery Master, simple to install fully automatic, fit and forget

 

[eddie]

The Vanbitz Battery Master

No More Flat Engine Batteries The Battery Master keeps your engine starter battery topped up by linking it to the leisure battery. This automatic one-way action passes a small trickle charge to the engine battery whenever its voltage becomes less...

www.motorhomefun.co.uk

Tens of thousand sold

 

[pappajohn]

The Vanbitz Battery Master

No More Flat Engine Batteries The Battery Master keeps your engine starter battery topped up by linking it to the leisure battery. This automatic one-way action passes a small trickle charge to the engine battery whenever its voltage becomes less...

www.motorhomefun.co.uk

Tens of thousand sold

If the starter battery is flat after 3 weeks and if the vans in storage for say 12 weeks....over winter.
Will the BM keep the battery charged for 12 weeks?

 

[pappajohn]

You generally don't need to change the alternator when fitting lithium

I was referring to a lithium starter battery, if there is such a battery yet, regarding the alternator....again, if there is such a thing.

 

[Vansflyer]

I was referring to a lithium starter battery, if there is such a battery yet, regarding the alternator....again, if there is such a thing.

Not seen a lithium van cab battery yet but lots of motorcycle owners fit smaller ones to save weight. Cranking power needs are different to draining a leisure battery so less of a need for lithium I suppose in a van.

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[eddie]

If the starter battery is flat after 3 weeks and if the vans in storage for say 12 weeks....over winter.
Will the BM keep the battery charged for 12 weeks?

No, but it wouldn’t really be a good idea to leave it for three months without starting it, it is after all intended as a delivery van, stop started every day

The Battery Master would probably extend the period to six or seven weeks though

 

[Vansflyer]

No, but it wouldn’t really be a good idea to leave it for three months without starting it, it is after all intended as a delivery van, stop started every day

The Battery Master would probably extend the period to six or seven weeks though

Do you have the specs of what voltage the leisure battery has to be to charge the cab battery? The reason I ask is that the docs say that it works if has solar or hook up? Obviously if the voltage differential is known the amps available / top up to cab battery can be worked out based on that and give a rough time frame for how long the leisure battery will keep the cab battery charged. Ta

 

[autorouter]

How easy is it for you to access the storage place? I think there are a few ideas for a solution to your problem.

You could get a 'Power Station' device, which is a battery in a box with a charger and inverter, and produces 240V mains if you want it. A smart charger can be plugged into the inverter, connected to the starter battery. It will charge the battery up to 100% if there is enough chasrge in the power station, but it may take a few hours. Then take the power station back home to recharge it. Probably not worth getting one just for this job, but if you can think of other uses for it as well, it's worth considering. Something like one of these.

Portable Power Station to Charge and Explore- Jackery

Lithium-ion Portable Power Stations with whopping capacities and AC outlets, solar ready for backup power, CPAP & small appliances. Learn more and shop on Jackery.

www.jackery.com

Alternatively, if you already have a slave battery and a small smart charger, say 5A or so, you could get a small inverter about 150W, which is small enough to plug into a cigarette-lighter socket. You could charge the battery at home. Then take the battery, inverter and charger to the MH. Connect up to the starter battery and charge until full. You could leave overnight then go back to collect it for recharge. I used this method in the past, before lithium batteries were around, and it worked fine. I used a CTEK MXS5.0 charger, 5A. Small enough to work with a 150W inverter, large enough to fully charge the battery.

Your existing method of connecting a second battery in parallel to share charge works to some extent. It will certainly prevent a flat battery and ensures you can always start the engine. But in the long term a lead-acid battery needs to be taken to 100% every month or so to avoid deterioration due to sulfation, so using an inverter and smart charger will do that.

Another possibility is a CTEK device called the CS Free. It's a jump starter power pack, but it has a lot of extras. The internal lithium battery, like most of these jump start devices, is quite small, about 5Ah. Enough to start the engine, but not big enough to refill an 80Ah battery that's fairly flat. However unlike other jump start packs, this one can be connected to a spare battery such as your slave battery, and will transfer the charge to the target battery. I've not tried this CS Free, but at least one other Funster has one and has used it successfully if a similar situation to yours.

CTEK CS FREE 12 Volt 20A Portable Battery Charger - 40-462

The CTEK CS FREE 12 Volt 20A Portable Battery Charger The CS FREE is a completely portable charger that will charge any 12V lead acid, AGM or lithium battery up to 130Ah. The CS FREE has an internal battery that is easily charged via USB and will hold it's charge for up to 1 year. This means you...

www.tayna.co.uk

 

[martincath]

Hi All
Thanks for all the brilliant replies, this site is a treasure trove of knowledge. Whilst some of the suggestions seem really good but a little complicated, W are not sure how long we will keep this moho first one and all that so we are going to go with the trickle charger between the leisure battery and the vehicle battery. There is the Vanbitz Battery master and the AMT12-2, not sure which is best, the AMT seems to have a stopping point if the leisure battery gets down to a 11.5v. Not sure if the Battery master has that facility. They are both the same price so that is not a deciding factor. Might have to flip a coin!!

 

[poppycamper]

Hi All
Thanks for all the brilliant replies, this site is a treasure trove of knowledge. Whilst some of the suggestions seem really good but a little complicated, W are not sure how long we will keep this moho first one and all that so we are going to go with the trickle charger between the leisure battery and the vehicle battery. There is the Vanbitz Battery master and the AMT12-2, not sure which is best, the AMT seems to have a stopping point if the leisure battery gets down to a 11.5v. Not sure if the Battery master has that facility. They are both the same price so that is not a deciding factor. Might have to flip a coin!!

Remember you get Fun discount on Battery Master... but you have to mention when ordering.... not after

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[Revolvor]

Remember you get Fun discount on Battery Master... but you have to mention when ordering.... not after

It's still cheaper to buy via the MH Fun shop. I ordered one yesterday!

Scroll right to the bottom of any post and click on MotorhomeFun Shop

 

[Madcaravanner]

There's a SIMPLE solution

a small solar panel connected direct to the cab battery when not in use you disconnect it when you turn the ignition on but then you store it away until you park up
We bought one as our Lockdown Alarm/Tracker system does drag the battery down this way as long as there's light my battery is full

 

[poppycamper]

There's a SIMPLE solution

a small solar panel connected direct to the cab battery when not in use you disconnect it when you turn the ignition on but then you store it away until you park up
We bought one as our Lockdown Alarm/Tracker system does drag the battery down this way as long as there's light my battery is full

OP states moho stored under cover.