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| Haa,haa - Jason- Nice urban legend. That was true when batteries had wooden cases. There is one killer of batteries-> charging abuse by the owner. Charging abuse falls into two general catagories:
1.) Undercharging! Either not charging it for enough time to reach full charge (a "smart charger" with automatic shutoff or float cycle will solve this problem) or not recharging the battery immediately when you get home or back to the dock. Its not good to leave a battery set for days in a discharge condition. It causes the battery to lose capacity. (You are the solution to this problem)
2.) Overcharging! Overcharging can kill the battery much quicker. This falls into some basic sub-catagories.
a. Do you use a standard 10-15A automotive type charger and leave it connected for days? Then you're cooking your batteries- A deep cycle battery and 10A charger use should be recharged from a full discharge in ~ 24 hours or less
b. This one is a little more insidious- over charging the battery when ambient temperatures are high. Batteries are designed for an 77 degree Fahrenheit environment. They don't tolerate overcharging in a high ambient environment. Do you recharge your batteries when it's 85-100 degres F. outside or with sun beating down on the boat? (A "smart charger" with temperature compensation will solve this probelm) .
Smart chargers cost money- most times more than you may have paid for the battery- There is another solution- get yourself a battery state of charge meter or a cheap digital voltmeter from Rasio shack or where ever, just make sure it will read 4 digits when set to a 20 volt scale (12.70 not- just 12.7) They should be able to show you at the store before you purchase it. I prefer the digital voltmeter because I can use it to troubleshoot electrical problems in the boat, boat trailer or the truck. Here's a little chart you can use to determine the battery state of charge.
State
of Charge 12 Volt battery Volts per Cell
100% 12.70 2.12
90% 12.50 2.08
80% 12.42 2.07
70% 12.32 2.05
60% 12.20 2.03
50% 12.06 2.01
40% 11.90 1.98
30% 11.75 1.96
20% 11.58 1.93
10% 11.31 1.89
0 10.50 1.75
Measure the battery voltage before you turn on the charger. This will tell you what the battery state of charge actually is, i.e., how much power you've taken out. If the state of charge is 40%, you've taken out 60% of the battery's available energy. That also means that you can approximate how long it's going to take to recharge the battery. If it's takes 24Hrs to fully recharge it with a 10A charger it will take 24 x.6 = ~ 14.4Hrs to recharge it. Do not discharge your battery below 10.5 volts![:knockout:]
I wrote an article for Muskies Inc. late last year on this same subject(“Most batteries don’t just die, they’re usually murdered!”). Maybe I'll go dredge it out of the archives and knock the dust off of it and send it in for the articles section. Much to complex to delve into in depth here. There was also an very good article in Infisherman magazine. The only thing I disagreed with was a statement about "smart chargers" , it went something like "connect it and forget it". Really bad advice if the boat is going to be setting for more than a couple days.
Al Warner
www.spongebobwasseenatthenorthpole.com [:0] | |
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