Thread: Charging Weirdness

I suspect that the battery monitor has to be reset after fitting the new battery.

Originally Posted by Graeme

I suspect that the battery monitor has to be reset after fitting the new battery.

Agree...

That was done when the new battery was fitted. To be sure did it again after noticing current draw from the battery while driving yesterday. No change in behaviour.

No faults recorded. No lights on the dash.

I don’t think it’s faulting at all.

Over run charging is what it does, and cycling the battery down and back up is a good thing.

Check your terminals are all nice and clean and tight.

Sometimes too much information can be concerning and may just be normal (but monitor for a period of time for good measure).

Have you checked on your GAP that your vehicle systems have all the latest updates?

Originally Posted by Tombie

I don’t think it’s faulting at all.

Over run charging is what it does, and cycling the battery down and back up is a good thing.

Check your terminals are all nice and clean and tight.

Sometimes too much information can be concerning and may just be normal (but monitor for a period of time for good measure).

Have you checked on your GAP that your vehicle systems have all the latest updates?

Well, if it's normal then it's something I never noticed before. Having said that, the previous battery was a dud (lasted a little under 12 months & replaced under warranty). That is, it would never accept much charge even when the BMS ramped up the voltage to 14.9v trying to get it to take some current.

So seeing large drains and accepting large charges while driving is something I have never seen before but I have to say anything that leaves your battery in a lower state of charge than it was when you started doesn't qualify as 'smart' charging for me.

Have to wonder whether the previous batteries demise was the result of the crazy charging algorithm or it was just a dud. It was a Varta G14, so no el cheapo. Problems with that battery is what caused me to start watching battery related parameters while driving in the first place.

My BMS software is probably not up to date so I'll chase that up but going O/S for ~3 weeks on Sunday so nothing is going to progress in the short term.

The BMS software can be updated using GAP's fast track system, yes?

EDIT: attached screen shot showing current draw while driving. By this stage the battery SOC had dropped to 88% from the original 99% when started in the morning. At 88% SOC the alternator is still not supplying enough current to run the vehicle yet instantly puts out ~80+ amps the second the brake is touched and the battery will take 50 amps. Overall though, net battery current flow is negative because of flat road and even flowing traffic conditions - hence braking and coasting is not often required - hence the declining SOC.

Gap Screenshot_20180629-113404.jpg

IIRC LR specify that the battery is only maintained to 80% capacity so if more than that then the BMS may be allowing it to drop, saving fuel while doing so. As Tombie said, monitor it for a few weeks when you can.

Originally Posted by Graeme

IIRC LR specify that the battery is only maintained to 80% capacity so if more than that then the BMS may be allowing it to drop, saving fuel while doing so. As Tombie said, monitor it for a few weeks when you can.

Thanks, didn't know that.

Bit of a worry when your running a fridge - solar charger does it's best to charge the battery to 100%. BMS does it's best to discharge the battery to 80%. Crazy IMO

The amperage the alternator is pushing can't be right. It needs almost 60 A just to keep the systems running so the 26 from the alternator + the 13 battery doesn't make anywhere near 50+. Where is the shortfall coming from? The dual battery?

I also have a problem understanding my charging system some days.

Occasionally when the vehicle has stood for a couple of days with the fridge running & the batteries are down a bit it won't charge at all. The first time I noticed this feature, I drove for 45 min with no charging except on overrun & then it shot up to 200 A. After the first restart all was normal & the voltage shot up to 14.7 followed swiftly by the amps. Stop/start has worked every time since.

When we stopped in Moranbah after travelling 900 km in 2 days from Brisbane, my vehicle battery was at 100% At the end of day 1 of the trip it was at 85%. Maybe it charges to 100% only on even numbered days of the month, who knows.