Is there any reason not to always charge a dead deep cycle battery at the highest charge rate on the charger? Does the charge rate have any effect on the life of the battery/plates?
There are lots of times my battery needs to be charged when I know I won’t need it for a while and even the 2A setting would have it charged by the time I need it and that is what I currently do. But if there is nothing to be gained by doing that, I would just as soon put it on the 10A setting and be done with it sooner.
I talked with my battery guy last week about this and he told me its better to charge on the 2a setting but you can charge on the 10a. The reason was over my head, if needed I can ask him for the details. He is a commercial battery salesman / technician and knows more about batteries and chargers than I knew there was to know about them.
If your batteries are dead - your boat motor can charge your deep cycles at 35-50A per hour - they can handle it. But, 20% of the rated amp hours is the typical max charging rate. A group 27 battery has 100+/- Amp hours, so charging at 20amps is the max. 8-10amp is recommended, 2a is fine.
I talked with my battery guy last week about this and he told me its better to charge on the 2a setting but you can charge on the 10a. The reason was over my head, if needed I can ask him for the details. He is a commercial battery salesman / technician and knows more about batteries and chargers than I knew there was to know about them.
Yeah the details of why you should use 2A or even 5A on Deep Cycles is pretty complex.
Bottom line, the fast charge rate shortens the life of the Deep Cycle battery and will eventually affect it’s full capacity of a charge. You can turn a 100AH deep cycle into a 80AH deep cycle (or lower) by charging it too aggressively.
This is why I don’t let my motor alternator charge a deep cycle and only charge them with a smart charger.
Your deep cycle batteries will stay stronger longer if you do this.