Thread: Love this remote Bluetooth battery monitoring

Originally Posted by Ozzy119

Not yet. I've only travelled a few KM with it so far, but never got it (hard foot down) above 13.81

Hi Ozzy, it sounds like your batteries are pretty well charged.

Also note, if your auxiliary battery is an Optima Yellowtop, then at 13.71v, you can still fully charge it.

A Ferret pointed out, there are a number of factors the BMS takes into account when setting the operating voltage, so after a week or two, try discharging your setup down a bit and then see how the BMS reacts.

With D3s and 2.7 D4s, they have a 30 second start up routine, where the voltage remains low and the ECU determines what high voltage to operate for the next 30 minutes, then it settles down to a normal operating voltage. There is more to it but that is the basics.

Except for the 2.7 D4s, all D4s have a more complex BMS control and this monitors a range of factors, beginning with the startup voltage. You may not see a rise in your voltage for a number of minutes after starting, or if the cranking battery is low, the voltage may rise very quickly after starting.

Your BM2 monitor is ideal for learning how your vehicle is effected by your driving style.

If you can, post up some graphs when you have done a few days driving. This will help others to compare operating voltages and driving habits.

Originally Posted by drivesafe

Hi Ozzy, it sounds like your batteries are pretty well charged.

Also note, if your auxiliary battery is an Optima Yellowtop, then at 13.71v, you can still fully charge it.

A Ferret pointed out, there are a number of factors the BMS takes into account when setting the operating voltage, so after a week or two, try discharging your setup down a bit and then see how the BMS reacts.

With D3s and 2.7 D4s, they have a 30 second start up routine, where the voltage remains low and the ECU determines what high voltage to operate for the next 30 minutes, then it settles down to a normal operating voltage. There is more to it but that is the basics.

Except for the 2.7 D4s, all D4s have a more complex BMS control and this monitors a range of factors, beginning with the startup voltage. You may not see a rise in your voltage for a number of minutes after starting, or if the cranking battery is low, the voltage may rise very quickly after starting.

Your BM2 monitor is ideal for learning how your vehicle is effected by your driving style.

If you can, post up some graphs when you have done a few days driving. This will help others to compare operating voltages and driving habits.

Thank you for clarifying this. Mine is a 2.7D4 with your earlier (2010) dual battery system (Yellow top) which is what I have attached the unit to.

I'll see how it all goes over the next week weeks.

Originally Posted by Ferret

I believe some earlier model vehicles have needed software updates to the BMS to operate properly so monitor it for a while, see how it goes.

Mine is a end of run 2016 model, but only showed this smart charging behaviour late last year when the dealer changed the cranking battery under warranty and must have updated the BMS software at the same time. So I’d expect this behaviour to a bit hit and miss.

Having ongoing troubles with my Traxide DBMS

For the last week I’ve had my main battery on trickle (7 amp Ctek), with the Traxide on and allowing my Optima to be charged also

After 1 week I jump in the car to get the annoying “Low battery please start engine” warning

WTF?

Disconnected both the Traxide and Optima negative terminal and recharged the cranking battery overnight

Is this normal??

Hi Brian, you need to post up your battery voltage readings so we can see if there is a problem or if it is a software issue.

It is commonplace in D4s to still get a “Low Battery, Start Motor” message, even though the cranking battery is fully charged.

Try doing a HARD RESET and see if this fixes the problem.

Again, post up your battery voltage readings.

So we made it to the dizzying heights of 13.94v on three trips today. All were over 30mins travelling time. That magical 14.4 is looking like an urban myth in the smart alternator world ha ha. No wonder the KK bank of 6 AGMs (200amp hrs) doesn't get a decent charge, even with a large volume of driving hrs in the day.

Brian, your cranking battery might just be on the way out. They just do that. No warning, no rhyme or reason.

Hi again Ozzy, do you use the dual battery’s in you D4 to run a fridge when not driving?

If your D4 batteries are fully charged, there is no reason for the voltage to rise.

Originally Posted by drivesafe

Hi again Ozzy, do you use the dual battery’s in you D4 to run a fridge when not driving?

If your D4 batteries are fully charged, there is no reason for the voltage to rise.

Thanks. All the accessories are turned off right now. So from what I can decipher it means the batteries are in good charge order and don't require a higher alternator input voltage. I'm heading away over Easter with everything plugged in and so will be interesting to see how we go. Very keen to see how the solar input goes with this level of info. Previously (for the car) I was relying on a volt metre. Not so accurate ha ha