# Battery to battery charger advice and info please



## celcat (Mar 6, 2013)

Sorry if this has been covered before but I haven't been able to find anything on here.

We've been looking at putting a solar panel on our mh but after being at the show this week have been told about battery to battery charging. It does seem to make sense as we will be using the mh over winter but here in the UK, not abroad, so will we really benefit from solar panels or battery to battery?

Has anybody any advice or info please? 

Thanks.


----------



## rosalan (Aug 24, 2009)

This has been covered many times and no doubt be covered again in future as it is such an important question.
The simple answer is to contact VanBitz and buy a 'Battery Master'
This has three wires, one goes to the leisure battery, one to the engine battery and one to ground. This clever tool then makes sure that your batteries are all getting solar support and you should never have a flat van battery.
Full instructions come with the unit.
There is much, much more that could be said but this is the simple answer.

Alan


----------



## Techno100 (May 8, 2010)

Yes for using through the winter the Sterling battery to battery will be more useful than solar.
I have the BtoB and 300watt solar


----------



## VanFlair (Nov 21, 2009)

I guess that the B2B is only any use when you are running the engine so it depends on time spent stood still where you could get some solar gain vs time spent with the engine running where the B2B does its stuff, whatever that is (rapid charging of leisure battery by fooling the alternator into working harder) thanks google.

Martin


----------



## Techno100 (May 8, 2010)

It will ensure a recharge while moving from site to site whilst a normal alternator delivery might only be a few amps at best.


----------



## The-Cookies (Nov 28, 2010)

we have a Ctek unit fitted, not quite as powerful as a sterling but very effective and cheaper, we can also charge 2 bike battery's while on the move with out taking power from leisure battery's.

John


----------



## bmb1uk (Jul 8, 2009)

try ringing sterling direct, to see if they have any refurbs to sell , I got one earlier this year.


----------



## celcat (Mar 6, 2013)

Thanks for the replies, all very much appreciated. Definitely going to be looking into this more after some sleep (night shift )

One quick question.... I know that the battery charges when driving but is it not possible to let it idle to charge?


----------



## Techno100 (May 8, 2010)

Yes but not great for the engine 
I would however if I ever needed to


----------



## Techno100 (May 8, 2010)

Of course there is no point in all this investment if you only have one battery? First upgrade !


----------



## TerryL (Feb 19, 2009)

I'm with Techno100 here. Get an additional battery to double your off-grid capacity (if you haven't already got one of course) then a Sterling B2B charger - they're dead easy to wire up if you want to do it yourself. Apart from a failed battery (yes it can happen!) this setup has never let me down (yet!) and with normal useage I've managed 5-7 days off grid.

Helps if you've converted to LED lighting etc. as well.

A solar panel won't be a lot of good in a UK winter.


----------



## listerdiesel (Aug 3, 2012)

TerryL said:


> A solar panel won't be a lot of good in a UK winter.


They are surprisingly good if you have the right setup, but you'd never get the same power as you do in the height of summer, that's a given.

Peter


----------



## nicholsong (May 26, 2009)

celcat

I have a Sterling B2B fitted feeding 2X 90amp batteries and it only takes 15-30 mins driving every 2-3 days to top them up.


Peter is correct that idling an engine is not a good idea, but I think if you had to resort to run it static, because you are not travelling, but are prepared to sit on the throttle or put it on a stick at say 1500rpm just once in a while I doubt you would do the engine much harm - there seem to be a lot of HGV drivers who run their engines on idle for 10 mins. before moving off

Sterling have now got a new unit (cannot remember the name) which may be better than the B2B. Call them - very helpful.

I am not knocking other makes, but Sterling do have a good name amongst professionals for producing a good product - not cheap, but cheap is not often good. 

I have got a similar system (Adverc) on my boat but had I known about Sterling then I would have gone for the Sterling. 

Geoff


----------



## WildThingsKev (Dec 29, 2009)

I fitted a Votronic b2b charger to our van just before leaving for Italy last week, very impressed so far. We have been quite light on battery usage most evenings so apart from the initial boost after leaving home of around 35A it has just been ticking over. Nevertheless the batteries are still around 12.75v last thing at night so are obviously getting a good charge.

The big test comes in Jan and Feb, skiing with no hookup.


----------



## erneboy (Feb 8, 2007)

listerdiesel said:


> They are surprisingly good if you have the right setup, but you'd never get the same power as you do in the height of summer, that's a given.
> 
> Peter


Interesting that you should say that Peter. The solar calculator on here disagrees: http://www.motorhomefacts.com/modules.php?name=SolarCalc

put some figures in and see for yourself. Do you think it is inaccurate?

My own experience with our old setup of 160w of panels with a pre-MPPT regulator was that on a clear winters day I might get 2 or 3 amps on a clear day and little to nothing on a cloudy day.

I don't know what the new set up will bring but it is impressive on a sunny summer day in the UK peaking at around 14 amps, Alan.


----------



## Mrplodd (Mar 4, 2008)

I have a 100w solar panel, 2x115 AH leisure batteries and the solar panel keeps BOTH leisure batteries AND the starter battery fully charged whilst on my driveway in the winter.

I have a Sargent EC 325 unit that is prewired for solar and does all it needs to do without any intervention from me. Brilliant system.


----------

