In the back of my mind I wonder what was done to maintain these batteries whilst some vehicles were in 'batch and hold' for so long? Mine was built in January and soon to arrive. Were the batteries disconnected, kept on a maintenance charge, let go flat with constant discharge, replaced? Who knows.. just have to wonder eh.I haven't driven the vehicle for a weekso I checked the voltage between the charging post and the closest earth: 12.5V or ~70%
I connected a new Victron 15Amp smart charger ...took about 1 hr 50 mins to register the "green light" float status. I let it settle then checked the voltage again after 10 mins with two different multimeters. One registered 12.59V, the other 12.60V. ...say about 80%. I would have expected higher. I didn't have time to check the battery status on the main display.
Ok, your fridge is running off the starter battery as it supplies the 12V socket in the boot. If you aren't driving enough to recharge the starter each day, it starts to fall behind so each night you start with less & less capacity to run the fridge until eventually the starter gets so low in the morning it can't start the vehicle. The service battery would've been trickle charging the starter continuously across the Smartpass sensing it was low, but it's only designed to maintain a charged starter, it can't supply enough charge to keep up with the fridge load. I'd say it would've also lost ground overtime to the point where it was also depleted and wasn't able to assist the starter to turn the engine over. Short drives to the next camp doesn't work well when you're running a fridge.
Agree it should've rested around 12.7-12.8V, maybe it lost 0.1V over the cable and connections to the starter, although I imagine it's fairly hefty cable.I haven't driven the vehicle for a week
I connected a new Victron 15Amp smart charger ...took about 1 hr 50 mins to register the "green light" float status. I let it settle then checked the voltage again after 10 mins with two different multimeters. One registered 12.59V, the other 12.60V. ...say about 80%. I would have expected higher. I didn't have time to check the battery status on the main display.
Interesting on several (german) web article is written that EFB‘s should not charged in AGM Mode. Normal battery mode is the right one. Now I am confused what is right.
.I'm not sure how well you should rely on the vehicles indication of SOC as being exactly accurate. How do they establish this? Is it simply via voltage or is there a shunt involved? Can it be reset? Noting that the battery when being tested is not in an open cell state so it's either charging or discharging and this will have some effect.
I mentioned somewhere previously that the % readout would only be a rough guide and to basically ignore it and just watch the voltage. If the % display wasn't there owners wouldn't be fretting over SOC, you'd only see voltage as with most vehicles, the average punter knows if they see 11.9V something's not right but when it's displaying +12.0V all is good. There has to be some sort of shunt (likely a basic one) near the battery to show that % reading but they never do a good job of calculating charge or discharge, the peukert exponent and charge efficiency factor settings are mostly a shot in the dark so overtime the battery monitor starts to 'drift' and tell lies. To fix, you need to periodically charge the battery with a 240V smart charger to float to reset (recalibrate) to 100%, another reason to regularly charge the battery with a good charger. Battery monitors like the Victron BMVs can auto reset or be done manually but some cheaper/basic shunts will only have an auto reset and no user interface.
The 'normal' battery mode on the Victron is 14.4V (bulk). This article talks about charging EFBs and AGMs, about half way down.
Not sure the trickle charging at 3 secs bursts could keep up with a fridge load overnight. I'd say it's really only designed to maintain a small (maybe 100-150mA, 3 - 4Ahrs/day) 'at rest' self-discharge on the starter when say the car sits unused for weeks at a time. The average 55L fridge would use around 20Ah overnight, so with losses ~24Ah needs to go back in.
"Curiouser and curiouser"
) (perish the thought...what an embarrassment!!!)Sorry
Maybe you caught the service battery doing it's 3 second burst of trickle charging the starter, which would've been happening since the service battery's voltage is higher than the starter's.
Ah! Thank you Mark...
Shame they don't have an isolation switch like Mercedes have.View attachment 7821578I’ve just back in my Grenadier after 5days in a marina car park and my state of charge is 94%. That’s not too bad I think
Do you recall what the level was when you parked it, and had you manually charged the battery beforehand?I’ve just back in my Grenadier after 5days in a marina car park and my state of charge is 94%. That’s not too bad I think
