Keep your engine battery charged

Cheaper alternative to the well known 'Battery Master' (around £60, I know I've got one) is this unit, whether on solar or mains charge, it will charge engine battery once leisure battery is near full charge. Only three wires to connect..


http://www.ebay.co.uk/itm/SOLAR-WIND-SPLIT-CHARGE-LEISURE-ENGINE-BATTERY-CAMPER-MOTORHOME-BOAT-12V-/331302696690

I had one fitted to my last 2 vans excellent  never had a flat battery.

John.

With this unit keeping both batteries charged when on hookup at home or away, does it allow both batteries to drain power when not on hookup ie  if on a site with no hookup for a couple of days on battery power only?

Rod

oops Just read in more detail about this unit and it appears that once the leisure battery drops below a certain voltage it stops it will not draw anything from the motor battery 
Am I correct in this assumption? 

2004 Ford Duetto Automatic 2.5 with batteries under drivers seat As I have had recent issues with both batteries (now sorted), while I had the drivers seat removed for better access I wired a separate positive & Earth from each battery to a chocblock connector to a position where I could easily use a voltmeter to check voltage of each battery. 

So looking at the wiring of this unit I could utilise the two separate blocks and I would also fit a in line fuse as recommended and also fit a separate on/off switch


Rod

Do you know for sure that the two batteries are independent? I know that on the older (1999 and earlier) Transits, the auto versions ~always~ had the batteries permanently twinned - permanently connected together. However, I don't know if that's true of the Mk.6.

No I am not sure, there are a lot of wires in there.

When I was having battery problems I was taking regular voltage readings and it appeared that if I was charging one battery to full it did not then increase the voltage of the other and visa-versa.
Would the voltage on both batteries increase if they were twinned? 

Maybe if I put an enquiry on the "Van Conversions" forum another member may know

Rod

They can't be twinned then. The batteries on the older auto Transits are linked by a heavy cable (at the back of the starter motor IIRC) so they ~always~ showed the same voltage reading.

If yours don't read the same voltage with the engine off then it must incorporate some sort of split charge relay or equivalent. It's not unusual for these to fail, as they have to carry very high currents when activated - because in their simplest form they just connect the alternator, the starter battery positive and the leisure battery positive together when the engine is running. However, they can be more sophisticated than that these days...

Thanks for that info. 
I think for the time being when at home I will put the van on hookup and charge the motor battery as this gradually over time drains with the alarm being on, and then every so often switch over onto the Hab battery and see how I go on.

Only had the camper for a couple of months so I am still on a steep learning curve. 

P.S. as a true practising Yorkshireman this is the cheapest way.  


Thanks again for the help & advice 

Rod

Thanks. 

When I got the camper I had a problem with the Eberspacher heater sometimes working and sometimes not, eventually after a proses of elimination I found out that there was not enough volts in the battery to get it going. 

Checked the Hab battery to find it was bone dry and had some buckled plates. So I don't think the battery levels had been checked for a long long time.
 
Fitting a new battery solved the problem   

Rod