Alternator- what revs does it kick in?

[Oldrat]

A question to the leckie techs in here if I may.

I’ve a converted 2018 2.0 crafter with, I presume a standard (not high power) smart alternator.

A couple of times the van has surprised me with the message “vehicle battery low, charge by driving.”

Both times, we had driven quite a distance to our over night park up, hence the surprise at the warning. No heated anything or power hungry stuff being used.

I do drive my camper like a pussy and often play whats the highest MPG I can get, so the revs are often quite low, say 1400- 1600 rpm.

I’m wondering..
1. At what revs should the alternator kick in?
2. Battery possibly on the way out
3. Shouldn’t my solar setup be charging the vehicle battery as well?
4. Would a higher output alternator be much use and if so roughly how much to change?

 

[Lebowski]

To answer you:
(1) Afaik: The revs are not the trigger for the alternator to kick in, it's the shunt that registers the flow of Amps, the Battery Control Module calculates how the battery State of Charge is and tells the alternator to deliver those Amps.

To really understand I'd like to see a SSP that the mechanics use as training material.

These below are screenshots from a program called OBD Link which talks to the vehicle control modules among which the ECU with the OBDLink LX Bluetooth dongle. OBDLink® LX - Top-Notch Scan Tool Compatible With Motoscan OBDLink LX

I use that to visualize what my vehicle is doing.







(2) Have your battery tested at a car parts shop, they can tell you what the condition is.
(3) Your HB (Household Battery) should charge your SB (Starter Battery) but you need a device for that to function. Victron and Votron have these built into the invertors and are relatively crude, Ablemail has a system that works better. Costs more too, but you get what you pay for.
(4) Higher output alternator: depends on your travel profile, how much solar you have and how much battery capacity you have and how much you consume from the battery.

 

[Oldrat]

To answer you:
(1) Afaik: The revs are not the trigger for the alternator to kick in, it's the shunt that registers the flow of Amps, the Battery Control Module calculates how the battery State of Charge is and tells the alternator to deliver those Amps.

To really understand I'd like to see a SSP that the mechanics use as training material.

These below are screenshots from a program called OBD Link which talks to the vehicle control modules among which the ECU with the OBDLink LX Bluetooth dongle. OBDLink® LX - Top-Notch Scan Tool Compatible With Motoscan OBDLink LX

I use that to visualize what my vehicle is doing.

View attachment 1446

View attachment 1447

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(2) Have your battery tested at a car parts shop, they can tell you what the condition is.
(3) Your HB (Household Battery) should charge your SB (Starter Battery) but you need a device for that to function. Victron and Votron have these built into the invertors and are relatively crude, Ablemail has a system that works better. Costs more too, but you get what you pay for.
(4) Higher output alternator: depends on your travel profile, how much solar you have and how much battery capacity you have and how much you consume from the battery.

Sadly I’ll need time to decipher that. I appreciate your taking the time to reply, thank you

 

[Raul a/3]

You need a battery master Brian, vanbizz sells them, also the mororhomefun shop. Same price both. Ablemail needs the right settings to work from lithium to lead, but, it does work.
Your alternator is 180A standard same as my van, no issues there.
How old is your starter? Mine is 2018 original battery, maintained by the multiplus inverter auxiliary output.

Forgot to say, when you get that message, disable stop start, and turn the lights on. The ecu will up the charge to the starter battery.

 

[rod_vw]

I can confirm that the Ablemail AMT12-2 unit works OK with my TGE, lithium leisure & original engine battery. I had the problem of the engine battery going low until the Ablemail unit was fitted.