Charging the Cab battery (1 Viewer)

[The Rolling Stones]

Just a quickie, having spent ages looking at split chargers to top up my cab battery whilst idle for months, I found an easier option. I swapped my single PV charge controller for a dual battery version, a single heavy duty positive cable run to the + side of the cab battery and away you go. I’ve added a trio of digital voltage displays so I now have the incoming (or inverter) mains voltage, cab and hab voltages.
All in all, cheaper and easier, provided you have a PV panel! (ps - check that the controller is able to deal with the max output of your panel)

 

[andy63]

nice one...
another option to ensure the engine battery is charged is to fit a battery master type device..
there are a number of suppliers of these devices and its also very simple to fit..
it also has the advantage of keeping the engine battery topped up from the leisure regardless of charging source... ie not just solar...
Andy

 

[The Rolling Stones]

fit a battery master type device..

Any chance of a link to such a product, I can only find switches when I look.

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[Two on Tour]

I fitted one of @eddievanbitz battery masters to ours and you get 10% discount as a Funster.

https://www.vanbitz.com/product/battery-master/

 

[funflair]

I fitted Vanbitz to ours and a Votronic one to a friends van, both do what they should.

Martin

 

[Nasher]

Or you can buy it from motorhome fun for less:

http://shop.motorhomefun.co.uk/product/battery-master/

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[andy63]

Or there is this one that andy @Techno put me on to a good while ago
Most probably the cheapest one around..
Sterling also do a similar device and they all have slightly different charging priorities and cut in and out voltages...
http://www.cbe.it/en/csb2/
Andy

 

[Ingwe]

And then all you need to do is find a place where you can connect to both the leisure and vehicle batteries. Not so straightforward if the batteries are not next to each other or you can't easily locate say, a split charge relay.
All auto-electricians listed where I live are busy till mid June at earliest and mechanic who services car scratches his chin and goes "ooh, will need to think about this" hardly instilling confidence.

 

[Two on Tour]

And then all you need to do is find a place where you can connect to both the leisure and vehicle batteries. Not so straightforward if the batteries are not next to each other or you can't easily locate say, a split charge relay.
All auto-electricians listed where I live are busy till mid June at earliest and mechanic who services car scratches his chin and goes "ooh, will need to think about this" hardly instilling confidence.

Not a big deal to fit.
Mine is located next to the hab battery stuck in place with heavy duty double sided tape. One wire to the hab battery positive and the earth to the hab battery negative (my hab batteries negative are earthed out to the vehicle chassis) The wire to the starter battery goes through the floor via an existing cable exit and is cable tied to an existing cable run to the front of the vehicle and enters the cab area near the starter battery again through an existing cable entry point. The power to the starter battery from the Battery Master is low amperage so does not need to be a thick jobby. Connect the said wire to the starter battery positive and job done, make your self a cuppa and tell the other half how great you are.

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[Lenny HB]

Or there is this one that andy @Techno put me on to a good while ago
Most probably the cheapest one around..
Sterling also do a similar device and they all have slightly different charging priorities and cut in and out voltages...
http://www.cbe.it/en/csb2/
Andy

I've recently upgraded my solar regulator to a Votronic although it has a dual output it's only 1amp to the starter battery so decided to keep my CBE2 in circuit as it have a much better charge rate and all the time the leisure batteries are in a good state of charge it will keep the starter battery topped up.

 

[andy63]

It is as simple as paul suggests.. the most difficult part is running the wires to the two sets of batteries...but even that isnt necessary if you can locate connections to the hab and vehicle batteries at say the power supply unit in the van ie sargent or whatever.. its acceptable to make the connection there ...
If you do choose to go to the batteries and you have a battery monitor fitted remember to make the connection to the shunt and not the battery post if you want to keep everything right in terms of battery capacity etc..
Andy.
A little afterthought about the connection to the leisure battery posotive ..
I have a shunt on the posotive terminal hence my comments (its a sterling unit ) but it is more normal to fit it to the negative terminal with most battery monitors so may not be an issue when connecting to the leisure posotive for most installations...

 

[Ingwe]

@CCC- can I ask, how do I know whether the negative post on my leisure battery is earthed like yours? I follow the basic instructions but am unclear whether the ground lead of the BM, can be attached to the negative post of my leisure battery.
I would like to have a go at doing this myself especially as all the techies where we keep the van, seem unsure about what to me, seems a really simple task.
One other question, for the long wire needed to go from the BM to the cab battery, should this be the same thickness as the wires coming from the BM? I know people have posted it doesn't need to be thick but I presume the same as supplied with the BM would be best?
Many thanks.

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[Two on Tour]

Both the starter battery and battery need to have a common earth that being the negative side of each of the batteries and that's normally the vehicle chassis.
Don't worry about the starter battery as that will have the negative terminal going to the chassis. with the hab battery, try and trace if there is a thick cable going from the hab battery negative to a point on the vehicle chassis. If that's not possible then let me know if you have a multi meter (test meter) and if you do does it have a continuity setting. If you don't have one then it's about time you had one as it may get you out of a lot of trouble in the future.

 

[Stealaway]

nice one...
another option to ensure the engine battery is charged is to fit a battery master type device..
there are a number of suppliers of these devices and its also very simple to fit..
it also has the advantage of keeping the engine battery topped up from the leisure regardless of charging source... ie not just solar...
Andy

Why would you need one of these? If you have a source for charging the leasure battery it must also be charging the starter battery. What am I missing?

 

[andy63]

Why would you need one of these? If you have a source for charging the leasure battery it must also be charging the starter battery. What am I missing?

You may well be missing nothing... i just said another option!!
And just because you have a charging source to the leisures doesnt have to follow the start battery gets anything. That may be true of yours ...it very much depends on your van.. on older ones i believe that wasnt the case...and ive read countless threads of folk asking how to ensure their engine battery gets charged when the engine isnt running..
As i said above a nice feature of fitting one of these devices is that it charges the start battery from the leisure regardless of charging source to the leisure ie solar, ehu , wind , efoy , etc ...and as lenny has indicated above some are capable of a higher charge rate than the existing system ..
Andy

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[Two on Tour]

It's normally the case that the hab battery is charge while the engine is running but the starter battery is not charged when the hab battery is being charged on ehu or solar.
If the vehicle is then left unused for a long period of time the the starter battery can run down to a point at which the vehicle will not start. The Battery Master over comes this problem.

Andy beat me to the answer but as I had typed out my answer, you can have that as well.

 

[andy63]

Both hab and start batteries have a common negative to the vehicle chass as has been saidi... on these devices it matters not where you connect the negative to..ie to the start battery negative or the hab battery negative... or a good fitting to the chassi...if you can find one... just whatever is most convenient.
Thats how i see it anyway and its always worked
Andy

 

[Ingwe]

All's clear now and all I need to do is go and buy a length of cable.
Will report back later in the week, when either it's done successfully or I'm sitting weeping next to a smouldering motorhome.

Thank you all for your input. Much appreciated.

p.s. for Stealaway's benefit, our vehicle battery is not charged when on hookup and as the van is stored inside, the solar will not keep the vehicle battery charged.

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[Stealaway]

How do you keep the leasure batteries charged? So for most people a battery master would be just belt and braces?

 

[Ingwe]

@Stealaway-we keep the leisure battery on hookup and separately, we had the vehicle battery connected to a so-called smart charger made by Halfords. This worked fine, or so we thought until our MOT 10 days ago when they told us that the vehicle battery was damaged, probably by overcharging. The casing was indeed split and you could see the plate pressing against the side suggesting the plate had distorted.
So, whilst we can keep the leisure battery charged by the van's internal charger, this does not charge the vehicle battery. Hence the need for the battery master.
Until that is connected, we have connected the Halfords not-so-smart charger to the vehicle battery but put in a 24 hour timer that turns the charger on for an hour every day then off again.

 

[The Rolling Stones]

Since starting this thread I've now considered changing my setup - the trickle charge idea via a Battery Master seems a really good idea to minimise the risk of damage to the Cab battery - added to that, I'm considering replacing the Lead Acid Hab battery with a LiFeYPO4 battery. Prices are becoming more reasonable and I'm fed up replacing the battery on such a regular basis. I've just found that they charge really well via Solar Charge Controllers, but at a rate of 14.4v which rules out the standard built in MoHo charger, which is my next headache - to see if I can turn it off. It has no separate fuse or switch - other than a circuit breaker which would also turn off the fridge - My summer project!
Thanks for all your comments here - I've found them really enlightening.

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[funflair]

Why would you need one of these? If you have a source for charging the leasure battery it must also be charging the starter battery. What am I missing?

The starter battery is not automatically charged when the leisure battery is on charge, sometimes but not always for example a single output solar regulator connected to leisure battery will put nothing into a starter battery.

Martin

 

[andy63]

the trickle charge idea via a Battery Master seems a really good idea to minimise the risk of damage to the Cab battery - added to that, I'm considering replacing the Lead Acid Hab battery with a LiFeYPO4 battery.

I have no experience with the jithium batteries but from brief reading of various threads on here know they require a precice charging regime and im not sure that a battery master device would be compatible with that...
Definately worth checking as you will be spending a lot of money going down that route...
Andy.

 

[Stealaway]

The starter battery is not automatically charged when the leisure battery is on charge, sometimes but not always for example a single output solar regulator connected to leisure battery will put nothing into a starter battery.

Martin

That's why I bought a dual battery solar controller and it was a lot cheaper than a battery mate.

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[Ingwe]

And now all we need is lotsa sun!!

 

[Two on Tour]

That's why I bought a dual battery solar controller and it was a lot cheaper than a battery mate.

Yes I agree that a dual battery solar controller is an option, but if you you did not take that option in the first place of it is a second hand van again without a dual battery solar controller fitted or you store your van for long period under cover with no ehu or sunlight then a Battery Master is a good option to go for to help in having a starter battery in a condition to start the van.

 

[two]

Both the starter battery and battery need to have a common earth that being the negative side of each of the batteries and that's normally the vehicle chassis.
Don't worry about the starter battery as that will have the negative terminal going to the chassis. with the hab battery, try and trace if there is a thick cable going from the hab battery negative to a point on the vehicle chassis. If that's not possible then let me know if you have a multi meter (test meter) and if you do does it have a continuity setting. If you don't have one then it's about time you had one as it may get you out of a lot of trouble in the future.

True. There's a negative side to everything!

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[two]

So long as you refrain from using the starter battery (via dash-mounted 12V socket) for anything whilst not on the move, I’ve found that the starter battery is looked after adequately by the alternator.

An additional trickle can’t do much harm but may be unnecessary. If the starter battery starts to stop starting (if that makes sense) I’d suggest it’s time to replace it. Additional charging methods will only delay the inevitable.

 

[eddie]

I have no experience with the jithium batteries but from brief reading of various threads on here know they require a precice charging regime and im not sure that a battery master device would be compatible with that...
Definately worth checking as you will be spending a lot of money going down that route...
Andy.

Battery Master has no effect on the charging regime of any battery whatsoever

 

[Two on Tour]

So long as you refrain from using the starter battery (via dash-mounted 12V socket) for anything whilst not on the move, I’ve found that the starter battery is looked after adequately by the alternator.

An additional trickle can’t do much harm but may be unnecessary. If the starter battery starts to stop starting (if that makes sense) I’d suggest it’s time to replace it. Additional charging methods will only delay the inevitable.

I think your missing the gist of this thread in that this is not concerning the starter battery running down on a day to day basis while you are on tour or on site for a few days but more for the long periods of non use when the starter battery naturally looses charge plus the modern electricery that runs in the background when the vehicle is to all intense and purposes switched off.

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