The best way to charge trolling motor batteries?

[BassChump]

I have an old bass boat that I fish from several times a week weather permitting.

I just bought 2 new batteries for the trolling motor. I've hooked them together so I don't have to change connections when one battery loses power.

I'm just wondering what is the best way to charge them. I have an old charger but it has always worked very well. It's a variable amp charger. What I usually do is charge it at about 5 amps and the charger automatically slows the charge as the batteries get charged up. When it gets to below 2 amps of charge rate, I remove the charger.

Is this method ok or is there a better way to charge the batteries?

My old batteries still worked but they didn't seem to last as long as when they were new. That didn't bother me much on the lakes I fish because there was very little water current to deal with but lately I've been fishing a river for smallmouth and it's tidal waters so I fight the current a lot which taxes the batteries. It was almost like my old batteries developed a memory. The charge time started to be much less and the run times were way down as well.

I just want to make these batteries last as long as possible so I want to know the best way to make them last.

               Thanks.

     

[cottontop]

My bass boat came with an on board charger.  It is totally automatic.  

It is very light as it doesn't use the old heavy transformer like old chargers use.  I believe it is called a inverter type charger.  It stays hooked up to the batteries all the time and it has a cord that I plug into an outlet.  It has two banks and charges my trolling and engine battery at the same time.  The electricity it produces is cleaner than old charges and it slows it self down to almost nothing when the batteries are charged.  It gives you a green light when it is done and you can leave it on all the time if you wish.  I also have a portable one like it that I bought at Lowes and use it on all of my other batteries.  It really works great and charges your battery right every time.  Also my portable one has other functions like a battery reconditioner and tester, reverse polartity protection and charging system tester.  I believe it was like 65 dollars.

[clipper]

If you fish several times a week you will appreciate a fully automatic onboard charger and your batteries will too. You just plug it in when you get home and forget about it except for checking water levels regularly and keeping the terminals cleaned and coated.  The secret to long battery life is keeping them fully charged and charging them properly.  A good quality onboard charger does that for you.  I have had a Dual-Pro three bank charger for a little over a year that charges both trolling motor batteries and my cranking battery too.  I bet the guys on the web site will be glad to share their thoughts on the best brands.

[Andy Taylor]

Is it OK to charge a deep cycle battery after every time out? Or does it depend on how much you use it each time out? I just have a stand alone charger also.  

[Jig Man]

I have an old charger but it has always worked very well. It's a variable amp charger. What I usually do is charge it at about 5 amps and the charger automatically slows the charge as the batteries get charged up. When it gets to below 2 amps of charge rate, I remove the charger.

Is this method ok or is there a better way to charge the batteries?

            Thanks.

     

I would set it higher than 5 amps especially if charging 2 batteries hooked parallel. If your T motor is pulling much from the batteries, I'd also get a hydrometer and check each cell before I unplugged it because if it is old and not actually giving you a full charge it will, over time, shorten the life of your batteries.

I have an onboard 3 bank 15 amp Dual Pro and it takes almost as many hours to get a flull charge as the time of the fishing.

Is it OK to charge a deep cycle battery after every time out? Or does it depend on how much you use it each time out? I just have a stand alone charger also.

NEVER NEVER NEVER allow your battery to set over a day before it is recharged. Do it as soon as you get home if possible.

[BassChump]

Thanks for the responses.

So is my charger ok for this? Are the on-board chargers better or just more conveinient????

Why would I need to recharge my engine battery when the engine charges it while it's running?

Sorry if these are stupid questions but I honestly don't know.

              Thanks again

[fishfordollars]

Is it OK to charge a deep cycle battery after every time out? Or does it depend on how much you use it each time out? I just have a stand alone charger also.

First thing I do when the boat gets backed in and parked.

[Wayne P.]

BassChump, if you fish more than you ride around, your engine may not completely charge the starting battery. Most of the time I spend about 10 minutes riding to the first fishing location and may stay in that area just using the trolling motor for 5+ hours. With two sonar units operating and livewell pumps sometimes, the run time is not enough to recharge the battery when returning to the dock. Just starting the engine, battery power is used that may not be replinished on a short run.

[NBR]

Years ago the word was to run your TM batteries way down before you recharged but today those who know battery technology say to charge up after each use and keep them charged. Idon't know whether the technology has changed or the batteries and charger are better but since I put an onboard in my boat I have been much better served.

Onboard chargers are so much more convient that most people will just take care of their batteries better with an onboard. A new onboard will provide the lates technology although my 15 year old 3 bank Dual Pro has served  me very well.

Most boats are set up with the cranking battery serving the big engine, live wells, lights, depth sounders ,  everything except the TM. Unless you run very long distances the big motor charging system won't keep the cranking battery at full charge on some or maybe most boats.

[BassChump]

I see your point.

I didn't realize it but after some research I found that the charging system on my engine is only 16 amps. The lakes I mostly fish in are smaller lakes so I don't have the engine running much more than 4 or 5 minutes at a time so it wouldn't charge the battery much.

I haven't ever had the engine battery get discharged but I guess I should charge that battery now and then as well.

         Thanks for the info

[Fishbone]

I worked for Deka batteries servicing fork truck batteries and chargers. A fork truck battery is a deep cycle type. They are huge (2,000 #s) and get charged at 200 to 250 amps from the charger.

Now the deal on those batteries was that they would be good for 1,500 charges.....more if well cared for. I'm not sure the same deal goes for small batteries, but I would think yes.

So, if some one offered you 1,500 fill ups on your car's gas tank, you sure would use more than a 1/4 tank between fill ups.

But then it's always nice to start a fishing trip with a fully charged battery.

The other deal is not to let a battery stand for a long time in some discharged state. Sulfate builds on the plates which degrades performance.