Originally Posted by
drivesafe
Yep this is a major potential problem, more so with D4s but to a lesser degree, also with D3s. Continually going to the vehicle and causing the computers to wakeup so many times that the cranking battery is discharged to a level where it can not start the motor is a common problem
The issue of ending up with a flat cranking battery while camping, is actually more likely if you do not have one of my systems fitted and even if you do end up with a flat cranking battery, the D4 can usually be started from the auxiliary battery because in this type of situation, my isolator has worked in reverse.
From feedback from customers and first hand experience, D4s fitted with my systems are far less likely to suffer from a low cranking battery after a weekend away, for a number of reasons.
The main reason is that weeks before you even go away, my system is working at keeping your cranking battery in a higher state of charge possible, than it would be in a D4 without one of my systems fitted.
Right from when you first start your motor, with any other DBS or no DBS at all, 100% of the energy required to start your motor comes from your cranking battery. Which is how it normally is.
With one of my systems fitted, because my isolators keep the batteries connected for up to days at a time, 25% or more, of the energy required to start your motor will come from the auxiliary battery.
This one single advantage means that your engine is going to be easier to start, your cranking battery has not had to work as hard as it normally would thus helping to extend the cranking battery’s lifespan.
But more importantly, because the cranking battery has not been discharged as low as it would need to be in a single battery setup, you will be able to replace the energy used while starting the motor, in a shorter drive time and now days, with many of these vehicles being used for lots short drives, this one feature/advantage, is helping to keep cranking batteries in a higher state of charge.
While your are driving round town, because the D4 alternator has such a huge current capacity alternator, both batteries are easily charged, even during short drives.
Now when you have finished driving for the day, we come to another feature/advantage of the way my systems work.
Regardless of whether it has been short or long drives, when you turn off your motor, the auxiliary battery, an Optima D34 Yellowtop in 99% of D3 and D4 setups, will always be in a higher state of charge than your cranking battery.
Shortly after you turn off your motor, because the batteries remain connected, and as the Optima is in a higher state of charge, the Optima S-L-O-W-L-Y back discharges into the cranking battery.
This slow back discharge not only helps to keep the cranking battery in a higher state of charge, but over a period of time, usually just a few weeks, it will also bring the battery up to a much better condition. And this means the battery maintains a higher capacity.
This all means that wth your battery being in a far better condition, you will actually replace the energy used while starting your motor, in an even shorter drive time.
And all of this occurs before you even start your holiday trip. It also means that you can go to your D4 more times while stopped, before you flatten your cranking battery.
But add to this, because the batteries are connected, you can access your D4 even more time before your cranking battery gets that low that it will not start your motor.
No other system offers these benefits and reduces the risk of a flat cranking battery while camping, and most other systems are a lot dearer.
Sorry for hijacking your thread Jeremy, but lots of people will be reading it and unfortunately you have been given some pretty woeful advice and others need to be able to see there are better ways to achieve what you are trying to do, with out the potential problems that can occur.
I wish you the best and hope your system meets your needs.
