Leisure Battery not reaching full charge on Alternator

Any Dc-Dc charger or B2B charger (Sterling, Voltronic, Victron). Will also future proof you if you decided to go down the route of LiFePO4 (Lithium Batteries) one day 👍🏻.
The problem is mass production vans use basic split-charge relays/systems which are fundamentally 4-pin relays either soldered into a circuit board or hard wired using very poor quality cable. Idealy for best results, uprated cables with something more substantial such as a Dc-Dc charger will improve the engine to leisure charging no end and as the Dc-Dc charger is fundamentally a pro-charger powered when the engine is running, you are getting a much improved rate of charge With improved results.
 
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I wouldn't mind betting that your LB @paulhelenwilko could do with a deep cycle recharging session.

Both of my LB's were not only not holding their charge but even after charging them for a week or more with a standard chargerneither of them reached more than 12.8 volts which they then both started to loose (without any loading) at approx. .5 volt per week.

I then subjected them both to very long deep cycle recharging sessions and they now top out at 14.2 volts which they also hold when not connected to the system.
 
I have read a lot recently about smart alternators - could a 2013 Ducato have one ?

Does the motorhome mains charger have a deep cycle ?
 
I had a 2013 citrone van with a smart alternator I bought a cheap CIG lighter fit volt meter .that confirmed how poor the output was .the cure is a battery to battery charger for smart alternator . if it is not a smart alternator you are probably expecting to much from your alternator your fridge on 12 v uses a lot of available amps .
 
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Tony Lee said:
Almost no standard alternator will come close to fully charging a house battery
Best you might do is 85% and then only after several hours of driving
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I don't know how you have come to that conclusion Tony as for instance in my self built installation where I have a van battery which is connected via a split charge relay to 2 leisure batteries and at the end of a 2 to 3 hour journey all 3 batteries are showing over 14v when tested.
 
Some motorhome manufacturers use very feeble wiring and the voltage drop between engine and leisure battery is sufficient to stop meaningful leisure battery charging. In my opinion leisure battery charging is best done by a B2B and not left to incidental flows from the alternator if you need a full battery when you pitch up. Vital if you have a smart alternator.
 
Millie Master said:
I don't know how you have come to that conclusion Tony as for instance in my self built installation where I have a van battery which is connected via a split charge relay to 2 leisure batteries and at the end of a 2 to 3 hour journey all 3 batteries are showing over 14v when tested.
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Because the engine battery is only charged to 85 %
 
Here is charging from a 2017 Fiat Ducato alternator. This was a drive down a motorway, a bit stop - start and slow progress due to an accident. I will be fitting a B2B charger

Crox_to_S-Birm.png
 
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Millie Master said:
I don't know how you have come to that conclusion Tony as for instance in my self built installation where I have a van battery which is connected via a split charge relay to 2 leisure batteries and at the end of a 2 to 3 hour journey all 3 batteries are showing over 14v when tested.
Click to expand...
A 12 v battery con not be charged to 14 volts .check after a cooling of period about 6 hours 12.7 is fully charged .
 
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