Batteries

What are the best batteries to buy for using trolling motors, it's a duel battery set up and one blew up. Has an onboard charger that i left plugged in but was told they kick off and just keep the battery charged? I don't know why it happened but need to buy two new batteries and want to get what are the best. Also what is the best on board battery charger for keeping them charged? Thanks Crappiebait

So you have three batteries total? And the on-board charger you have now has how many banks? What model is it? I ask because there are a number of good chargers available, and you may already have one of them. Batteries can blow up due to reasons that are not the fault of the charger. A battery defect can do it, as well as letting them get dry. In order to know what battery to suggest, I'd also like an idea of your boat size/weight.

The best deep cycle battery Wal-Mart sells works just fine. Get a good on board charger and you may have one. You need a charger that conditions the battery as it charges and is a phased charger. Here's a link to one good brand. Best investment I made for batteries. These are also available from BatteryMart.com and some other places.
http://www.dualpro.com/

If the acid leaked out in the boat, look for problems where the acid got on anything. Especially the drain tube and plug.

My batteries went completely dry on me from leaving my charger plugged in all the time. The guy at the battery place said that the batteries aren't made to be left plugged in because when the charger senses a voltage drop, it will put full power into it until it goes back to fully charged. Every time it does this, you're boiling off a little more water. They told me to plug it in over night, then unplug it til the next trip so it won't keep cycling the charger on and off over time.

"The guy" at the battery place isn't always the electronics expert, either. If you have a "smart charger" (with digital electronics control), it will not boil out batteries as described. A "dumb charger" - you bet.

If a battery goes dry with a smart charger, it happens over a VERY long period of time (and was going to happen anyway from neglect), and the battery owner is at fault for not checking the batteries occasionally. Most good units go into a "float" mode where the required voltage is lower, avoiding frequent cycles of the charger. A bad battery will drop down rapidly, triggering the charger to try to recover it. So, quite often, it's the battery that is bad and causing the problem - not the charger!

A huge number of the bass guys (who work those trolling motor batteries hard) have theirs plugged in 24/7 and there is no chronic problem with people boiling batteries dry. I call "BS" on the "battery guy" when it comes to modern smart chargers. (mine need only a bit of water every 90-120 days.)

INTERSTATE BATTERIES.

Yes

Mine is a dual pro from 1997.

Thanks for all the advice! I have learned a lot and is my fault because I did not check them and left the charger plugged in all the time. Lesson learned for sure.

It's a 17ft. Lund, Im not home now out on the road working so I can't get the info. The batteries are continental marine/rv duel purpose but not sure about the charger.

Continental is a good battery also...

I'd buy Wal-Mart...they have a 3 year replacement guarantee and there's a Wal-Mart somewhere close by.

Years ago, there was a definite difference in battery life and quality...not so much anymore. The "good" Trojans are no more. the AC Delco maintenance free are gone. Sears has stopped selling their good battery.

Gman

Look at the Amp Hours on a battery to get the most time out of it. I bought a 100Ah battery from Amazon for $110. It weighs 62lbs but the charge on the battery can make it last 4 hours at full power for a 40lb thrust TM.
You want a sealed AGM battery. It will last longer and hold a charge better than standard cranking batteries.
If you run 2 or 3 in parallel you can conceivably be on the water all day for a couple of days!!
The price went up since I bought mine but you can still find them cheaper I am sure.
100 Amp Hour Battery on Amazon

"You want a sealed AGM battery." Why? Unless someone is seeking to skip the need to occasionally check electrolyte level in a boat's batteries, there's no compelling reason one should switch to AGM. The over-service-life cost WILL be higher, but there's no need to add water - that's about it.

When it's said that "AGM holds a charge longer" that doesn't mean that AGM technology lasts longer in use, it just means that if a battery sits dormant for months, the battery charge dissipates more slowly. How long a battery holds a charge once charged is typically of little concern to fishermen. Yes, AGMs do that, but we have chargers and power available to charge them frequently, so this minor feature isn't a game-changer.

An AGM battery doesn't last longer or provide more power than competitive batteries if similar models are compared. A battery with 200 minutes of reserve has more power than a battery with 180 minutes of reserve, for instance, regardless of the battery technology in use. (AGM vs. flooded cell) The same goes for cranking amps. There are batteries with good service specifications made with both AGM and flooded cell technology, and depending on which batteries are being compared, either may be the stronger battery with more power. An AGM batteries isn't just stronger and better because it is AGM - it just means there's no need to add water....

I set up a standard 24 hour timer to come on for an hour at noon and an hour at midnight and hooked up the onboard chargers via an extension cord. Batteries always seem to be fully charged though I will top them off the night before a trip just to make sure. This is the 3rd boat I have run this way. Last 2 didn't have an onboard charger so I used a manual charger. I had to find one that didn't require a switch being turned on manually and used the trickle charge selection. My Lowe pontoon had the trolling battery in the front and the starter in the back. So I made a "jumper" with an old 25' extension cord. Cut both ends off and put alligator clips on. Connected the charger to the front battery and then the "jumper" to the main. LOL seemed to work fine for the 5 years that I had the boat.

You may consider two Group 27 batteries for your TM (either deep cycle or dual purpose). You don't have a huge boat, so that could be a lot of weight for you. If you are really trying to keep the weight down, you can probably make do with two Group 24 batteries for a boat that size. It all depends on how "into" the TM you typically get. Heavy user, Group 27, Lighter user, Group 24 will do. Unless you have a lot of electrical equipment, a Group 24 is fine for the starting battery as I'm sure you don't have a big V6 back there!

You didn't tell us what onboard charger you have. When you get a look at it, let us know and we will comment. You may already have one that is adequate.

Your Dual Pro charger is designed to be safely plugged in continuously. If it is not malfunctioning, it won't boil off a good battery. I don't remember the exact profile for the older Dual Pro units, but I do know they shut down and monitor battery voltage, so they aren't really charging 24/7. When a given battery's voltage drops below a certain point, the charger will turn on that bank to recharge it.

Now, if you have a failing battery that won't hold a charge very well, the charger will cycle a LOT more frequently than it ever should when connected to a good battery. These frequent charging cycles will eventually deplete the electrolyte level. This problem is caused by a failing battery, not the charger. This is why one should check the electrolyte level as part of regular boat maintenance.

If a battery is found to be consistently low in electrolyte level when connected to a smart charger, that's typically a sign of battery failure - or it's at least at the end of service life. Another clue is noting one battery getting hotter than another when they have been charging for a while. All batteries will warm up when charging, but one notably warmer is a clue it's not doing well.

Crappie Bait, thanks for bringing up this subject. It reminded me to check my batteries and sure enough the electrolyte was almost down to the plates.

Two words...deep cycle...sorry you didn't look at the battery I linked.

I will be running this battery for the next six years on a 36 lb trolling motor on my kayak. Good luck on yours lasting that long.

kickingback, my point was that it is not necessary to get AGM technology to get good batteries suitable for deep-cycle applications. I am aware he should use batteries intended for deep cycle applications, and that was mentioned in my post. AGM may offer no more reserve power, but it certainly will increase the cost - both absolute, and typically on a per-use basis when the cost is amortized over the service life of the battery.

While the battery you purchased is fine for your application (and probably even preferred when used in a kayak), it isn't a marine battery. Marine batteries have been mechanically reinforced to withstand the pounding and other vibrations of use in a powerboat on rough water. That difference is why golf cart batteries don't hold up in boats, for instance, even though they are good deep cycle batteries.

Your Welcome bush hog, looks like I'm gonna be buying some batteries, lol

The battery charger is a Charge Pro?

I don't know what your charger is - you tell me. I asked you previously what charger you had, but you never answered that question. I was asking so I could determine if you already had a good charger. If you want help, you're going to have to pay attention and answer questions, or the effort is just wasting my time.

As to the discussion of Dual Pro chargers, I was responding to Jacob, who has a "Dual Pro" charger made in 1997. We had a discussion about that charger while waiting on your to answer. The company that originally made them made only dual bank chargers in the early days, so their name was "Dual Pro" and they retain the website dualpro.com to this day. Now that they make many products with various numbers of banks, the company is now known as "Pro Charging Systems".

There are quite a few good chargers available today. By no means is Pro Charging Systems the only one. Look at yours and report here with info on brand and model. Or do you even have a true onboard charger?

My trolling motor batteries are in a tough place to check the water levels so I put sealed no maintenance voyagers . Not a bad price and three years no problems ! If you can easily maintain and check the water levels I have had good luck with auto zone dual purpose batteries. Great reserve on the biggest one

If you ever wanted to switch back to flooded cell batteries, there is a technology for "watering" batteries that will fill each cell to the correct level without overfilling any other cell. Basically it is a set of replacement caps for the battery that has a valve for each cell. As the electrolyte rises, the valve closes, preventing overfill. All the cells for two batteries can be tied together with tubing in a kit. A primer bulb and a container of water are used to fill batteries without access to the caps. It works very well and is easy to use. One time cost is about $30 per battery.

Marine Battery Watering

About 2 years ago I installed two of Walmart's best Batteries and a GUEST brand on board charger and have been trouble free...
The previous charger always over charged and my batteries would run dry quickly.

I leave plugged in all the time and rarely ever have to add water... maybe once in two years.

Thats a bunch of charges and dishcharges as I make at least 150 trips a year to the lake.

Have heard good things about Guest chargers from others.

Lots of good info here about batteries and chargers. Thanks for the lessons!

i got a free lesson again. thank you. special thanks to flippin-out

Glad to help. I hope I didn't confuse anyone with info since we had more than one discussion going in the course of this thread. If something seems off in left field, ding me and I'll try to uncross the wires.

One other thing I will mention that I may not have covered but should have: onboard (smart) chargers will sometimes fail to charge a battery that has been deeply discharged. The battery is so "dead" that the charger doesn't sense it at the end of the charging wires so it never turns on that bank. This is partly a safety thing so that the charger won't try to charge a shorted battery, which could get some things very hot. The charger isn't broken. If you think this has happened, connect a traditional battery charger for a while to manually get that battery's voltage up a bit. Then remove that charger and try the onboard charger again. You may then see it wake up on that bank and start charging where it would not before. If that battery does this frequently, it's time to buy a new battery.

I've come to this conclusion when it comes to batteries... You either purchase optimum or optimum.

Finally got home and checked the charger it is a Guest 10 Amp, charge pro series. thanks Crappiebait

I have two Group 29 Batteries hooked up to my 24 Volt Minnkota Ultera. If you want to protect and Condition your Batteries, hook them up to a Minnkota Digital Charger. It will save you a bunch of money in the long run. Talk to David at Shut-Up-And-Fish.