Ranger Mods

Hi.. newbie post so please be kind!

I'm using FORSCAN to monitor my 2018 Ranger 3.2 on a 3 week trip. I have an aux battery installed via a DC/DC charger. Towing a van with Anderson feeding a 3 stage charger and 2 x 110Ah AGMs. Ranger is also supplying 12v to the 3-way fridge in van.

Anderson has a VSR on it, 3 way fridge wired direct to started battery (that was the way the elec wired it - going to get it changed when we get back)

When I started the trip a week ago SOC was at 84% - after driving for 5hrs (with a couple of rest stops) it was up to 92%

A couple of days ago it dropped to 62% so last night I put it on a CTEk 5A charger for 14hrs. Today SOC reads 44%

Am I doing something wrong, or is my battery dying? - it's a Ford genuine. I've only had the car for 3 months but I'm guessing it might be the original.

TIA

There is a lot for your alternator to do, it may be good if you can monitor alternator output.

I did just read yesterday that depending on dcdc charger set up that an external charger on the start battery can trigger the dcdc charger. It will then draw from the start battery. I would see if that is happening with the dcdc or the vsr. I am going to check my bcdc today.

I just did a test. I have a Redarc BCDC 25 with an auxillary battery under the tray.

I have driven over 1000km in the last days so my start battery is well charged.

I put a charger on at 8 amp setting and within a minute the voltage had increased and the BCDC had activated and was charging the auxillary.

My BCDC is set up with ignition on sense connected but if they dont sense ignition on they revert to 13.2 cut in.

I will be adding an Isolating switch so I can turn of the BCDC if I wish to charge the start battery.

Thanks Bala1 - I reckon you might be right! After posting this I was driving for 2 days without the van attached and...boom... SOC back up to 82% and its stayed there since.
Interesting about the DCDC being triggered and drawing off the starter battery. As I was only using a 5amp charger overnight that would make sense. Weird that the charger showed all 8 lights by the morning, indicating it had gone to trickle (even with the starter battery only showing 44% SOC.
Anyway, at least I know my starter battery is still ok.
Still learning about the Ranger and my new 12v set up - so thanks for the info - I might have to iso my DCDC too

How did you connect the battery charger? You need to connect the negative after the shunt and not directly to the battery.
Otherwise the car will sense the amps leaving the battery and none going in.

I don't think isolating the DC to DC is necessary.

TieNN89 wrote: ↑Sat Jun 05, 2021 9:09 pm How did you connect the battery charger? You need to connect the negative after the shunt and not directly to the battery.
Otherwise the car will sense the amps leaving the battery and none going in.

I don't think isolating the DC to DC is necessary.

Good pick up on the connection.

Isolating the DCDC or VSR would be dependant on your charge source and time.

If you have mains power, no time limit and the charger is large enough to cover the load of the main battery the Auxiliary battery and any load on the battery then its no issue.

If you are out bush and need/want to top up the start battery with a solar panel, like I was recently, then having the DCDC come on and link the auxiliary that is running a fridge means I did not achieve much if anything.

Pretty much.
If you are wanting to top up your mains battery with solar then you'd need to isolate it, otherwise you'd need a lot of big panels.

1. 5amp is a pretty small charger.
2. Check to make sure the DC to DC is not allowing charge to the 2 battery also. If it is then maybe it is not wired correctly. Pretty sure these are usually ignition dependant.
3. Make sure to never put charger on negative battery terminal and after shunt or to chassis or the vehicle BMS will not see the charge going to the battery hence low SOC.
4. Possibly look at turning off smart charge if not already to allow a higher SOC to the start battery.
5. Where possible wire any 3rd party items to the aux battery rather than the start battery.
6. Install a breaker at the main battery so you can manually isolate it from the rest of the setup when charging this battery.

Some of these points have already been made.

Personally I run a VSR with isolation breakers at front and rear. It means I can charge either battery independently or together depending on my requirements. I also have a 35amp mains charger mounted full time in the tub. I definitely see a better outcome when charging them independently of each other even with a 35 amp charger.