Re:Gen 4 "Smart" charging...

So yesterday I had a flat battery (10.5V).
Now I hadn't used it whilst there was corrosive salt on the road, so it had probably been standing 3 to 4 weeks.

I dropped the charger onto it for half an hour and got it started easy enough, and according to my clampmeter, the starter took it overrange (199.9A), but it charged at 14A- for about 2 minutes, then dropped to 4A! which must be the smart charge kicking in as it warmed up.

No wonder the battery goes flat now I don't drive 2 hours a day, it would take 10 hours driving to charge it back up now.

I don't have anything on the smart charge system, so I don't know if this is because the battery is duff, or it is a "design feature" (which I'm inclined to believe)

Anyway, the battery has been on the accumate since yesterday, and seems to be charging fine, none of the cells are bubbling yet....

I almost pulled the trigger on a new one from Tayna @ £60 but if the old one is still fine it would be a waste of money to swap it now.

Looks like I'd best drop the Accumate on it every couple of weeks in future.


 

I'm fairly sure that it charges mainly whilst warming up- because emissions aren't measured during warm-up (officially "A cold battery is more efficient at accepting charge"- yeah, right ), and then cuts back.
Certainly the forums for The Other Car are full of "My stop start is flashing" - because stop-start is disabled as the battery runs down, which it does if you don't drive for several hours a week.

Is there anything in the manual about testing it, or it's operation?
I'd happily buy a new battery if the battery is not accepting a charge, but as it provides 200A plus to start it when virtually flat I can't see how that could be the case.



I know it is no end of trouble for Fords, and the fix is to pull the pwm lead out of the alternator, and then it reverts to proper operation.
Smart Charge is a bit of a grey area shrouded in mystery on t'interweb.

 

Thanks.  Could you pull "Charging system specifications" please?

It doesn't read like what I know about Ford, their objective was to lower emissions, not to compensate for load, whereas this reads as if it increases output when there is a high electrical load.

Maybe it did charge a lot more when the blue light went out, I did my errands in it after I got it started, and it only took about 18 hours on the accumate, which is around 21AH, so either the battery is half capacity or it must have but a fair bit of charge in when driving.

I should have hung around measuring for longer yesterday, but it was bitterly cold here in the wind standing watching a meter.

 

Sounds like a weak battery to me. Charge it up with a charger then turn your headlights on (should be roughly 10-12A load). If the battery dies within half an hour it's due for replacement.

LesNewell wrote:

Sounds like a weak battery to me. Charge it up with a charger then turn your headlights on (should be roughly 10-12A load). If the battery dies within half an hour it's due for replacement.
 

Well it didn't die, but after half an hour it was down to 10V again, but it started, and this time it charged at 45A!, dropping back to 40A, and then by the time the blue light had gone out it was charging at around 14A.

Pulled the trigger on a new one, Varta for £60 (made in the same factory as Bosch apparently, and £2 cheaper)


No wonder the Led headlights blind everyone, they take around 5A each so they are 60W, and Leds are about 8x as efficient as tungsten halogen! (The headlights and sidelights took 12A all together)