04-01-2005, 10:55 PM
[cool][#0000ff]In simple terms, your Cuda will drain about 1/2 amp per hour from the battery. That means that a 7 amp/hour battery SHOULD last 14 hours, from full charge. But, there are variables. For example, the colder the temperature, the faster your battery gives up.[/#0000ff]
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[#0000ff]Another consideration is that you will not get full power for the 14 hours. If you start out with a tested voltage of 13.5 (full charge), it will keep dropping until it gets below 11. That's when you should recharge. You should never drain an SLA battery completely. They are not deep cycle batteries like you get for running electric trolling motors. So, the sonar will keep working for many hours on one charge, but if you run it down to the bottom a few times it will take less and less of a charge until it will not work at all.[/#0000ff]
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[#0000ff]I do not use an automatic charger. I have a $25 voltage tester from Radio Shack, which I use to check the voltage before I go on a trip. I put the 500 milliamp charger on long enough to bring it back up over 13 volts, if it is much below 13 volts. Then, after coming back from a trip, I check the voltage again, and recharge it back up before putting it away.[/#0000ff]
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[#0000ff]As has been suggested, a 500 milliamp (1/2 amp per hour) charger will replace charge at about the same rate your sonar unit drained the battery. The 1 amp charger will recharge it twice as fast.[/#0000ff]
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[#0000ff]If you don't have a voltage meter, first charge up the new battery by letting it charge for about 7 or 8 hours. If it has been idle for a few days between trips, top it off for an hour or so before going out. Then, as soon as you get home, put it on the charger for about half the time you were using the sonar. That's 4 hours for an 8 hour day, etc. [/#0000ff]
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[#0000ff]If you buy into more powerful sonars, that suck more power, you will need to test the before and after charge to guage how much it does actually drain the battery. Some units will drain a little SLA in two or three hours, even in warm temperatures.[/#0000ff]
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[#0000ff]Don't worry about your battery blowing up. Not likely to happen at the low amperage trickling into the battery. Believe me, plenty of them have been left on chargers too long. Still, they will last longer if you make an effort to keep them up to full charge, but no more than that. Even worse to drain them all the way down.[/#0000ff]
[#0000ff][/#0000ff]
[#0000ff]I have used only the simple $10 chargers for years, even without voltage testing stuff, and have gotten good use out of several batteries. Using a voltage tester and maintaining just a good operating level on your batteries will provide several years of good service for you.[/#0000ff]
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[#0000ff][/#0000ff]
[#0000ff]Another consideration is that you will not get full power for the 14 hours. If you start out with a tested voltage of 13.5 (full charge), it will keep dropping until it gets below 11. That's when you should recharge. You should never drain an SLA battery completely. They are not deep cycle batteries like you get for running electric trolling motors. So, the sonar will keep working for many hours on one charge, but if you run it down to the bottom a few times it will take less and less of a charge until it will not work at all.[/#0000ff]
[#0000ff][/#0000ff]
[#0000ff]I do not use an automatic charger. I have a $25 voltage tester from Radio Shack, which I use to check the voltage before I go on a trip. I put the 500 milliamp charger on long enough to bring it back up over 13 volts, if it is much below 13 volts. Then, after coming back from a trip, I check the voltage again, and recharge it back up before putting it away.[/#0000ff]
[#0000ff][/#0000ff]
[#0000ff]As has been suggested, a 500 milliamp (1/2 amp per hour) charger will replace charge at about the same rate your sonar unit drained the battery. The 1 amp charger will recharge it twice as fast.[/#0000ff]
[#0000ff][/#0000ff]
[#0000ff]If you don't have a voltage meter, first charge up the new battery by letting it charge for about 7 or 8 hours. If it has been idle for a few days between trips, top it off for an hour or so before going out. Then, as soon as you get home, put it on the charger for about half the time you were using the sonar. That's 4 hours for an 8 hour day, etc. [/#0000ff]
[#0000ff][/#0000ff][#0000ff][/#0000ff]
[#0000ff]If you buy into more powerful sonars, that suck more power, you will need to test the before and after charge to guage how much it does actually drain the battery. Some units will drain a little SLA in two or three hours, even in warm temperatures.[/#0000ff]
[#0000ff][/#0000ff]
[#0000ff]Don't worry about your battery blowing up. Not likely to happen at the low amperage trickling into the battery. Believe me, plenty of them have been left on chargers too long. Still, they will last longer if you make an effort to keep them up to full charge, but no more than that. Even worse to drain them all the way down.[/#0000ff]
[#0000ff][/#0000ff]
[#0000ff]I have used only the simple $10 chargers for years, even without voltage testing stuff, and have gotten good use out of several batteries. Using a voltage tester and maintaining just a good operating level on your batteries will provide several years of good service for you.[/#0000ff]
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