by dahoon » Sun Aug 06, 2006 12:11 am
I have been selling batteries and other auto parts for over 25 years. Here are some pearls of wisdom I have gained.
The difference between automotive and deep cycle batteries is the make up of the cells. Deep-cycles have thicker plates in their cells and the grids on the plates are different.
An automotive battery is designed to have its charged maintained, they really like to keep themselves fully charged all the time. The main job of an auto battery is to start the vehicle once the car is started then its work is done unless the alternator quits. The alternator is supposed to replace the amperage in the battery that was expended when starting the vehicle. That is if the regulator is doing its job. So they need to have lots of amps availible quickly, but die out sooner.
The deep-cycle battery has thicker plates in the cells and their grids are heavier, so its reserve capacity is longer and its charge can be taken down deeper. They are designed to have their amperage drawn down and then recharged. An important note when recharging a deep-cycle battery is: LOW AND SLOW.
I have taken a lot of WAL-MART batteries in as cores. There is a reason why they are so cheap, they don't use as much lead in their batteries so they don't hold up as well. Trojan is a decent battery. But, my preference is Interstate and East Penn and AC Delco put out the best deep-cycle bateries on the market.
Amp hour rating is and ambigous number that a manufacturer can place on a battery. The tests they use are that accurate. The reserve capacity of a battery is a more accurate gauge of the strength of a battery. It more realibly tells what the charge life of a battery is at the amperage draw.
Remeber when charging a deep-cycle battery do it LOW AND SLOW. A 6 amp or maybe a 10 amp charger can be used, but I wouldn't go larger.
I had even contemplated using two 6-volt batteries in series. That would give the biggest bang for the buck and the best reserve capacity. But didn't think we would be camping for that long at a time.
Mike