Anyone any idea of cost to upgrade alternator on a 2019 fiat ducato I'm using a sterling 60amp B2b and I've noticed that it's pulling my vehicle
battery low every few minutes and can't maintain a high charge.Ive replaced the vehicle
battery which was faulty checked the earths and positives the cable runs are all less than 2m from the vehicle
battery maximum current into the 2 sterling 120ah li leisure batteries 40a dropping to 25a all cables 16mm2.
When first fitted all seemed to be working well for the first month. I've now set the B2B at half power and the system seems to be managing that. We are high usage wife is restricted so enjoys her TV and has a cpap machine we've managed the last 40yrs without using generators or shore power but it's looking less likely we will be able to maintain our off grid lifestyle without extra power in, sensible suggestions welcome (with the odd sarcastic comment thrown in).
I have a similar arrangement on my T5 VW, 180 amp alternator, but not in the real world, a 40 amp Sterling BtoB (the old metal cased one) charging a 100 Ah Sterling
LiFePo4.
I've noticed that ambient temperature has a great effect on the charging, when the temp is down near zero I get the full 40amps but, like this summer 30 deg + it's dropped the charge down to 27 ish amps.
The alternator has built in temp compensation to protect the
battery, assuming the
battery is the same temp as the alternator, which is a bit of overkill as the alternator is tucked in behind the radiator and the vehicle
battery is well ventilated, so as everything heats up the output voltage of the alternator reduces.
Together with all the volt drops associated with the cabling, fuses etc this severely reduces the ability to charge your domestic through the BtoB.
I did a test on an alternator to see what sort of effect this had, so I built a rig with a mains motor driving an alternator and set a load to draw about twenty amps.
running in unheated air I got 14.4 volts, fine. I then cooked it with a fan heater and lost over half a volt and I don't think the temp was as high as in the engine bay right close to the radiator.
I think you should be using MIN 25 mm2 cabling even for you 2 meter run, mine is a 5 meter run and I found it needed min 50mm2 cables
Sterling make an Alternator controller which I fitted to old Yanmar engine in a boat but it had all old alternator which you could get to the the built in regulator and bypass it, with most modern alt's I found it's almost impossible to do this as like everything now it's not designed to be 'fixed'. It's also not designed for
LiFePo4 batteries but maybe could be kidded, reduce the float charge time.
Probably not much help but nice to hear someone else has noticed this effect.
