TM battery maintenance question

[airborne_angler]

I talked to a guy last night and said he heard the best way of mainaining a TM battery is to fully drain it prior to doing a full recharge. Said he used to keep a car headlight attached to the battery,allow it to go very dim and then recharge the battery. Supposedly this is supposed to prolong battery life. Any reasoning for this theory?

[burleytog]

That is patently false and a great way to severely shorten the life of a deep cycle battery.

[tennwalkinghorse]

Deep cycle batteries you really don't want to drain below 60% before recharging and starting batteries more then 80% I believe there are only so many charge cycles for both batteries . If you maintain your batteries right they should last about 3 - 5 years depending on there use. JMHO

[Way2slow]

I just posted on your 12V sourse post before I saw this one, read it. That is one of the dumbest things you can do to your battery.

The number of charge cycles is what the base a batteries life on. This is normally based on draining a battery down to 30% and recharging it to 100%. Your over the counter TM batteries will usually have 180 - 250 charge cycles, depending on the type and grade alloy they use. Your Wal-Mart batteries are going to be on the 180 end, your Trojans, Deka's, and a few other top brands are going to be on the 250 end of the scale.

Drain a battery below 30% and you shorten the number of charge cycles, drain it all the way down and you greatly shorten the number because the plates start flaking. On the other end, only drain one to 50% and you will almost double the charge cycles and that count increase the less the battery is discharged. At the same time, it's not recommnend to recharge a battery that is still at 85% or greater charge (however, if it's going to be a while before I use it again, I charge it anyway). A battery left 24 hours at an 80% or lower state of charge will start to sulphate.

As for replacing batteries every 2 - 3 years, I would never swap my TM batteries out that soon unless I was fishing the pro circuit where I was charging them a couple of hundred times a year. I have always averaged 5 - 6 years from Trojans and Deka batteries. Even then the batteries have only just started to degrade.

Now, with that said, I never run cranking batteries but three years, that's not only in my boat, that's in all my vehicles. I alway buy the biggest, baddest, cranking battery I can get and they usually have a 70 month or more life rating but I replace them every three years. They are just too cheap for the problems they can cause when they all of a sudden decide to die. A bad cranking battery can be the most expsensive battery you could ever own, boat or auto.

The biggest asset to long battery life is a high quality charge, and I'm yet to find a $50 or less charger that's worth a darn. Almost all cheap chargers are going to charge at more than 15.3 volts, the absolute max you should ever put into a flooded cell battery.

[Fishing Rhino]

Been reading about batteries, deep cycle vs regular, and why each is better in the use for which it is designed.

I did not realize that cycles were the key to battery life, and when they should or should not be charged.

It also shed light on the charging system on my 07 GMC pickup charging system.  

When the engine computer determines you are driving on a trip, it shuts the charging system off until the battery drops to just over 12 volts, then it turns the system back on.

The two stated purposes are better gas mileage (supposedly another tenth of a mile per gallon), and longer battery life by reducing the number of charging cycles.

The other factor it uses is consumption of electric power.  It does not shut the system down and night, or during other times of higher than normal battery usage.

Now I understand why allowing the battery voltage to drop rather than maintaining at a constant level increases battery life.

I also found it interesting that deep cycle batteries should be charged at a slower rate than regular automotive batteries, and why using an automotive battery in a marine application and vice versa will result in shorter battery life.

[DEISWERTH]

I just posted on your 12V sourse post before I saw this one, read it. That is one of the dumbest things you can do to your battery.

The number of charge cycles is what the base a batteries life on. This is normally based on draining a battery down to 30% and recharging it to 100%. Your over the counter TM batteries will usually have 180 - 250 charge cycles, depending on the type and grade alloy they use. Your Wal-Mart batteries are going to be on the 180 end, your Trojans, Deka's, and a few other top brands are going to be on the 250 end of the scale.

Drain a battery below 30% and you shorten the number of charge cycles, drain it all the way down and you greatly shorten the number because the plates start flaking. On the other end, only drain one to 50% and you will almost double the charge cycles and that count increase the less the battery is discharged. At the same time, it's not recommnend to recharge a battery that is still at 85% or greater charge (however, if it's going to be a while before I use it again, I charge it anyway). A battery left 24 hours at an 80% or lower state of charge will start to sulphate.

As for replacing batteries every 2 - 3 years, I would never swap my TM batteries out that soon unless I was fishing the pro circuit where I was charging them a couple of hundred times a year. I have always averaged 5 - 6 years from Trojans and Deka batteries. Even then the batteries have only just started to degrade.

Now, with that said, I never run cranking batteries but three years, that's not only in my boat, that's in all my vehicles. I alway buy the biggest, baddest, cranking battery I can get and they usually have a 70 month or more life rating but I replace them every three years. They are just too cheap for the problems they can cause when they all of a sudden decide to die. A bad cranking battery can be the most expsensive battery you could ever own, boat or auto.

The biggest asset to long battery life is a high quality charge, and I'm yet to find a $50 or less charger that's worth a darn. Almost all cheap chargers are going to charge at more than 15.3 volts, the absolute max you should ever put into a flooded cell battery.

Way2slow, I've always valued your opinion on batteries and followed them to a T. One question, what can happen to a boat motor/car when a starting battery goes bad? Thanks

Doug

[Way2slow]

If it opens and cell and just quits conducting, normally nothing, other than your stranded.  That is what happens when you drive to the store, come back out and the car is dead, won't even spin the starter over.

Where the problem comes in is when a battery won't fully charge and the charging system is pumping with all it's got to try and charge it.  The prolonged load on the charging system can burn out the altenator in a car and the rectifier/regulator or stator, or both in an outboard.  This can also happen when you jump off a dead battery and use the charging system to charge it.  Outboards are very prone to burn out because their charging system are nowhere near as robust as a vehicles.   Anyway, either one is going to several hundred dollars to repair.

The other problem in either you car or boat, connecting jumper cables usually create an arc that has the potential to zap/damage some very high dollar electronics.  

Because of the risk involved, plus just down right being stranded (been there, done that and don't plan on it happening again) and having seen too many times the burned out parts the create,  I just prefer to swap out my cranking batteries every three years and no more than four years.  Granted, my neighbors love it.  I'm still running a battery in my welder  I took out of my wifes Camery three years ago.  One neighbor is still running two in some old equipment he has I gave him a couple of years ago.

Dirty/bad connections at the battery can be just as detrimental as a bad battery.  

[Way2slow]

You want to hear something that totally sucks, right after posting this last post, my wife wanted me to take her to a storage unit we have. She pulls the van to the front door and we load up the stuff she wants to take. I drive about a mile to the storage, unload the stuff, go to start the van to leave and the frigging battery was DEAD! She then says it seemed a little slow to crank at the house. This is a three year old 70 month battery. Just as I was getting ready to walk back and get my truck, a guy happens to show up that had a jump box and got me going.

In the batteries defense, while driving back the volt meter was only show about 12 volts so it appears the altinator has gone out but I was soo ticked when I got home, I haven't bothered to check it yet. I rarely drive this van so it could have just been low too long and sulphated. Guess I'll have to check that one tomorrow.

[Fishing Rhino]

Here's a good read on the two battery types, right from the horse's (Exide) mouth.

It explains the differences and why they must be charged differently to optimize battery life.

http://www.exide.com/faq/faq_marine.html