[Tutorial] Increasing the charging voltage (14.5V)

[radek93]

I was finally able to improve the charging on the S70 / V70 / 850.
The original

Original regulator

Untitled7_20220402210811.png (395.39 KiB) Viewed 1236 times

regulator charged max 14.1V on the battery, but on average below 14V. I used a regulator from BMW, which looks similar to the factory Volvo.

BMW regulator

Untitled6_20220402203836.png (211.66 KiB) Viewed 1236 times

It differs in the connection, so you need to add one wire from the ignition supply to the first pin marked "IG". Of course, the original excitation "L" cable is connected to the second pin marked "L". The third "FR" is not connected (it is the output from the regulator informing about the alternator load). Of course, because of the plug, you have to enlarge the hole in the plastic cover.
Regulator reference numbers from BMW:

038903803C VW
052.000.051 PSH
1197311506 BOSCH
1197311516 BOSCH
1197311536 BOSCH
1197311545 BOSCH
1197311547 BOSCH
1197311557 BOSCH
12311713491 BMW
138999 CARGO
215296 ERA
81112232 POWERMAX
940038028 MAGNETI MARELLI
CQ1010553 CQ
IB545 WAI / TRANSPO
RTR3300 GHIBAUDI
UD01525ARE AS-PL
VR-B238 MOBILETRON
VRG46462 WOODAUTO
215297 ERA

[MrAl]

I was finally able to improve the charging on the S70 / V70 / 850.
The original Untitled7_20220402210811.png regulator charged max 14.1V on the battery, but on average below 14V. I used a regulator from BMW, which looks similar to the factory Volvo. Untitled6_20220402203836.png It differs in the connection, so you need to add one wire from the ignition supply to the first pin marked "IG". Of course, the original excitation "L" cable is connected to the second pin marked "L". The third "FR" is not connected (it is the output from the regulator informing about the alternator load). Of course, because of the plug, you have to enlarge the hole in the plastic cover.
Regulator reference numbers from BMW:

038903803C VW
052.000.051 PSH
1197311506 BOSCH
1197311516 BOSCH
1197311536 BOSCH
1197311545 BOSCH
1197311547 BOSCH
1197311557 BOSCH
12311713491 BMW
138999 CARGO
215296 ERA
81112232 POWERMAX
940038028 MAGNETI MARELLI
CQ1010553 CQ
IB545 WAI / TRANSPO
RTR3300 GHIBAUDI
UD01525ARE AS-PL
VR-B238 MOBILETRON
VRG46462 WOODAUTO
215297 ERA

Hi there,

Wow this is very very interesting. I have been wanting to do this on my 1998 v70 also and also on my old Hyundai when i had that car. The problem is, if you dont drive that often the battery does not charge well enough when you do drive it so a slightly higher charge voltage would really help here. 14.5 volts would be ideal for my car.

Question is, where do you find this part and how hard it is to remove and replace?j
I i could get it off, i could probably reverse engineer it and set the voltage to whatever i wanted to.

Any extra info would be appreciated, thanks.

Take care,
Al

[radek93]

You need to remove the rear plastic cover of the alternator. Then you will see the original regulator as in the first photo. You assemble the regulator from BMW and add the cable as described. Unfortunately, it is impossible to convert the original regulator so that it charges more. Adding a diode to the ground circuit causes only no charging. It is a regulator with 8 bit IC. I don't know where he gets the test voltage. With the regulator from BMW, you can theoretically regulate the charging voltage up by the voltage drop on the cable you add as described. I just don't know why if it is around 14.5V on the battery.

[Chieber]

differs in the connection, so you need to add one wire from the ignition supply to the first pin marked "IG". Of

I’m really bad with electrics. Does anyone know what wire from the ignition supply this is?

[jmartin919]

Or you could just buy a smart charger that would keep it fully charged at all times.

[Chieber]

A set and forget option sounds better though

[jmartin919]

I was referring to MrAI's situation where he says he doesn't "drive it that often". In that case a smart charger keeps the charge up and extends the life of the battery. That's better than fully charging it by driving it and then letting it sit for an extended period.