There is yet another downside for using the truck alternator system for charging your remote located deep cycle batteries.
The truck alternator system operates from sensing the truck start battery on when it needs charge etc...
The truck alternator follows the battery science and will produce around 14VDC when it is needed to charge the battery. Since the truck start battery is so close to the alternator then this is mostly the only thing the alternator sensors will see. i.e it probably will never know your remote battery is in the circuit as far as DC voltage sensing is concerned.
What will happen is the alternator will only keep your truck start battery charged up and all your remote battery will ever see will be the 13.2 float voltage coming out of the alternator.
Going back to the brochure you will notice it takes many many hours to return your remote battery back up to its 90% charge state just using 13.2VDC DC VOLTAGE only.. This doesn't take into account the available 20AMPs also required for the remote battery to draw to start the internal charging process...
This brings up another subj on deep cycle battery performance. We have found unless you only re-charge at the 50% charge state and go to at least the 90% charge state each time you re-charge the battery you cannot get the expected battery performance. It may look like it has charged alot but as soon as you start using it will drop rather quickly back to the 50% state of charge. If you continually keep doing a small charge like this your battery will eventually go bad on you.
We always follow the 50% charge state as close as we can and re-charge back up to the 90% charge state before using the battery again. Sometimes due to camp ground rules on when we can run our generator we have to do the 90% charge state in a couple of generator run times maybe only get to do two hours in the morning run and then three hours run in the early evening time frame.
Watching this as close as we do seems to really give us a good battery run through the night until 8AM the next morning running the planned thing we want to run...
We also follow the rules of doing a full deep cycle battery re-charge after about 12-14 charge cycles of the 50% to 90% charge state. The full charge state using the 2KW generator will require at least 12 hours of generator run time and most camp grounds we go to doesn't allow this... This is usually when we pack up and head for the house...
Depending on the battery banks is crucial for us to camp off the power grid so we take it very seriously... Some things you just can't skimp on...
This method can be helped in a big way of just adding 120WATTS of solar power to charge the battery bank during the day time hours when the sun is out. We haven't done this yet but is on the things to do. The more you can re-charge during the day means less time you will need to run the generator which fits into the camp grounds generator run time rules just fine...
just food for thought..
I'm sure others do it differently but this make us be very successful when camping off the power grid with our 255AH battery bank. we don't even think about it much anymore... I do keep a close watch on my meter panel however...
Roy ken
