school me on battery chargers

[colt100]

I have to admit, I'm not up on keeping my trolling motor batteries charged. I charge them after every use but if i don't get out fishing or during the winter, charging the batteries seems to slip my mind.

I have a 2-10-15 automatic charger that works well. However, after letting my batteries sit, it shows that the batteries are charged to about 80% or so. When I put them on the charger, they charge quickly and the charger shuts off when it gets to 100%. If I re-hook up the charger the next day, it still shows 80% charged.

I took one of my batteries in this year and the guy charged it back to 100%. I didn't get out fishing much because of work this year and the batteries are back down to 80% and won't charge more then that.

One of the batteries is an interstate and the other is an optimax. The optimax is new this year and the interstate is 2 years old. I would like to be able to have a charger that will bring these batteries back to 100%. What should I get?

On board chargers are not an option as I live in N. WI and winters get down to -30 degrees which would freeze the batteries if left in my boat.

I was looking at chargers and thought about this one:
http://www.batterystuff.com/battery-chargers/12-volt/gel-cell/BM12248.html

Not sure if that would work for my needs or if I would be spending 100+ dollars on a charger that does the same as my other charger. I'm assuming that I would need something that isn't an "automatic" charger that would allow me to keep charging the battery.

Thanks in advance.

[REW]

Colt 100.
First of all, you don't need to worry about -30 degrees on your batteries, if they are charged.
If batteries are in good condition, cold weather retards their natural discharge rate to near 0.
So, if you have a battery in good condition and fully charge it in the fall, you don't need to worry about it until spring. It is likely that it will not have discharged more than 10% or so over the winter - assumming that there has been nothing in the boat to discharge the battery.

The first thing that I would do is to pull both batteries and take them to a battery supply house of your choice and have them load tested. You may find that the batteries are just fine and there is an issue with your charger.

If so, replace the charger and move on.

If not, replace the defective battery or batteries and move on.

Good luck
REW

[colt100]

When I'm using the batteries during the fishing season, the charger works just fine. I bought it last year and it works unless i leave the batteries sit. If I use the batteries, the charger will charge it back to 100 % but when I re-hook the charger, the batteries still show 80%. This seems like it has something to do with the batteries sitting without being charged.

I thought that even though the batteries were 100% charged, the water in them would freeze if left in freezing weather for any lenght of time?? If I'm wrong about this, I'll look into some sort of on board charger and just leave the batteries in the boat hooked up to the charger.

[Hot Runr Guy]

If it bothers you to leave an on-board charger running all the time, maybe get a 7-day timer, and have it on 1 day a week, just to keep the batteries topped off.
http://www.amazon.com/Woods-59202-Vacation-Security-Appliance/dp/B001Q9EFT6/ref=sr_1_8?ie=UTF8&m=ATVPDKIKX0DER&s=hi&qid=1257704198&sr=1-8

HRG

[colt100]

It doesn't bother me, I just thought that having the batterys in the boat were not an option 9 months out of the year. We normally have ice on our lakes until mid april and freezing temps starting in oct-nov. It's already snowed here several times.

[retire55]

I purchased the battery charger you referenced 2 years ago. Completely satisfied. Easy to use for AGM, Gel cell and flooded batteries.

[yarcraft91]

Some battery chargers, like my Sears automatic 2-10 amp, charge the battery to a target final voltage, then shut off completely. That only seems to charge the battery to 75-80% of capacity. Others (like my Guest on-board) charge to a target voltage, then drop back to a "float charge", around 13.2 Volts. I find that if I leave the float charge attached for 12-24 hours, the battery is near 100% charged.

[stinkycat]

It doesn't bother me, I just thought that having the batterys in the boat were not an option 9 months out of the year. We normally have ice on our lakes until mid april and freezing temps starting in oct-nov. It's already snowed here several times.

REW is correct. If your batteries are stored with a full charge you should have no problems leaving them in your boat all winter at -30. I live in N. MN and we get considerably colder than -30 and I leave my batteries in the boat all winter. I go out once a month and plug in the "on-board" charger for a day or two. I could just keep it plugged in all winter but I am cheep on electricity and feel better doing it this way. Have never had a problem come spring.

[bob1]

I leave my on-board charger plugged in all year. Never had a battery problem. I get off the water and plug it in first thing.

My Ranger Reata 1850 has a 3 bank Dual Pro 15 amp per bank charger.

Bob

[boat nut]

It doesn't bother me, I just thought that having the batterys in the boat were not an option 9 months out of the year. We normally have ice on our lakes until mid april and freezing temps starting in oct-nov. It's already snowed here several times.

A fully charged battery won't freeze until -90. Think about it, if you live where it's cold, does your truck battery freeze?
I live in Saskatchewan, and I'm confident in saying it gets considerably colder here than it does there. I charge my batteries, check the electrolyte and top up if necessary and recharge. They then stay in the boat (disconnected VERY IMPORTANT) for the winter. Never lost one yet.

Back to your battery charger. You said "I have a 2-10-15 automatic charger that works well", which leads me to believe its a hardware store automotive charger, likely transformer based. These chargers do not work particularly well on deep cycle batteries, and will often lead to the symptoms you have mentioned. You really should consider an on-board multistage charger. If not, Minn Kota makes a portable multistage charger, the MK110 which will provide an excellent charge for your deep cycles.

[bvs]

I've got a neighbor who has an auto-type charger. After the battery is fully charged he plugs the charger into a timer like you'd use to turn your lights on while on vacation. The timer kicks on for about 15-20 minutes a day year round. It keeps the battery topped off and isn't hard on the battery at all.

[colt100]

http://www.batterystuff.com/battery-chargers/12-volt/marine-chargers/SC1500A.html

This is the charger that I currently have. I bought it on advise from here. Is this a bad charger? Should I be looking at another?

[Hot Runr Guy]

I had one of those for about 6 months, finally got rid of it. Like you said, it rarely gives the same results twice in a row, voltage readings all over the place. I'm a fan of the Dual-Pro line, they offer factory refurbs here: http://www.dualpro.com/store/items/9/

HRG

[darin]

It does sound like the charger you have is not one of the better "onboard marine chargers." I would second the Dual Pro chargers. Also, if one of your batteries is new and the other is two years old, I think most would say that's not a good thing, either. However, if you had them both load tested and find that they're both perfect, maybe you'd be okay. I'd grab two new deep cycle batteries of your choice and make sure you're putting a decent charger on them...

[W.W.]

I'll second the Dual Pro line of chargers.

I also ran their batteries back when they sold batts (they don't anymore); now I run the Cabelas AGM.

Several years ago about a week before the annual "Big Canada Trip", I started having troubles with the MinnKota charger and Excide Nautilis Gold wet cell batts I was using at the time.

Contacted Dual Pro for advice and had new batts and charger in 4 days; can't say enough about how accommadating their customer service was.

Future boats for me will have Dual Pro for a charger..........

Good Luck with your decision.

W.W.

[boat nut]

http://www.batterystuff.com/battery-chargers/12-volt/marine-chargers/SC1500A.html

This is the charger that I currently have. I bought it on advise from here. Is this a bad charger? Should I be looking at another?

I had a ship'n'shore, gave it away. While I can't disagree with the dual pro advocates, my Minn Kota MK220 has been bullet proof.

[Catch'nRelease]

Question for the experts. In my boat I only have room for one dual purpose battery (starting + accessories) in addition to the two deep cycles used for the 24 volt trolling motor. What's the best way to monitor the starting battery to make sure I don't run it down to the point where it won't start the main motor? Even though I haven't been stranded YET, with two sonar/GPS units, the live wells, plus maybe some radio listening this is always a worry for me...

[Hot Runr Guy]

Question for the experts. In my boat I only have room for one dual purpose battery (starting + accessories) in addition to the two deep cycles used for the 24 volt trolling motor. What's the best way to monitor the starting battery to make sure I don't run it down to the point where it won't start the main motor? Even though I haven't been stranded YET, with two sonar/GPS units, the live wells, plus maybe some radio listening this is always a worry for me...

Take a look at a Blue Sea #8251 DC voltmeter, with an adjustable audible alarm. http://bluesea.com/category/6/23/products/8251
I'm using one of these to monitor my 24V TM battery set-up.

HRG

[PRD1]

If your sonar has a voltage monitor like the Lowrance just go into overlay data and turn it on. It will tell you the voltage at the unit and since it is on your starting/accessory battery it will give you a good indication of the batteries charge level. If it gets much below 12V you are on the very low side. It should show 12.6V or so with a fully charged battery.

[yarcraft91]

If your sonar has a voltage monitor like the Lowrance just go into overlay data and turn it on. It will tell you the voltage at the unit and since it is on your starting/accessory battery it will give you a good indication of the batteries charge level. If it gets much below 12V you are on the very low side. It should show 12.6V or so with a fully charged battery.

Use the Lowrance voltage readout with caution. My Lowrances typically show 11.8-12.0 volts on the starting battery, usually only 30 minutes after I shut off the main motor and start trolling, running an LMS-527 or LCX-27C plus VHF radio. The reading seems to have less to do with battery condition and more to do with the power wiring and backlight level in the Lowrance unit. Shutting down the backlight will cause the voltage reading to increase by 0.4 volts. I've seen this with 3 different Lowrance units, two different boats, since the starting batteries (now 4-5 seasons old) were new.

[Pezman38]

Question for the experts. In my boat I only have room for one dual purpose battery (starting + accessories) in addition to the two deep cycles used for the 24 volt trolling motor. What's the best way to monitor the starting battery to make sure I don't run it down to the point where it won't start the main motor? Even though I haven't been stranded YET, with two sonar/GPS units, the live wells, plus maybe some radio listening this is always a worry for me...

Even though I have never had a problem, from time to time while fishing I will just start my motor and let it run for 10-15 minutes. It puts more charge back in the cranking battery to ensure you get home later with your livewell full. Then when I get back I throw the charger on it overnight regardless to how full it is, it will get it to 100% by morning.

[Catch'nRelease]

Even though I have never had a problem, from time to time while fishing I will just start my motor and let it run for 10-15 minutes. It puts more charge back in the cranking battery to ensure you get home later with your livewell full. Then when I get back I throw the charger on it overnight regardless to how full it is, it will get it to 100% by morning.

Yes that's what I've been doing, starting the motor now and then and throwing the charger on each time I'm done for the day. So far so good, except for one time when the starting battery failed completely and wouldn't even try to crank. Fortunately I was on a smaller lake and was able to use my trolling motor to get to the dock. But I wouldn't want to have this happen when at the other end of a much larger, remote lake and was just looking for some other ideas!

Thanks to everyone who offered suggestions -

[sdlabman]

I have had a starting battery fail, on my lund 2025, NEVER again.

Since, I have added a new AGM for my main motor, starting battery, which i also added an additional 2 bank charger to charge. This battery does nothing other than start the main engine...

My 3 other batteries only run the bow mount trolling motor, which are charged by their own 3 bank charger..

Works perfect!

[Pezman38]

Yes that's what I've been doing, starting the motor now and then and throwing the charger on each time I'm done for the day. So far so good, except for one time when the starting battery failed completely and wouldn't even try to crank. Fortunately I was on a smaller lake and was able to use my trolling motor to get to the dock. But I wouldn't want to have this happen when at the other end of a much larger, remote lake and was just looking for some other ideas!

Thanks to everyone who offered suggestions -


Yep there is always that one time, that is why I keep a set of wrenches in my boat. If the starting battery dies due to failure, I unhook my trolling battery and use it to crank the engine. Works great considering you don't want to carry spare batteries due to the weight. My kicker also has a pull cord if that happens.

[darin]

Hey Boat nut... how much was that? I have been really looking for something just like that to use on my 24v system. Do you have two of them (one for each battery) or can that thing handle a 24v system?

ps - I private messaged you...

[boat nut]

Hey Boat nut... how much was that? I have been really looking for something just like that to use on my 24v system. Do you have two of them (one for each battery) or can that thing handle a 24v system?

ps - I private messaged you...

Would that be the MK110 you're referring to? It has 1 bank @ 10Amps. and is around $90.00Cdn.
http://www.minnkotamotors.com/products/battery_chargers/portable_chargers/mk110p.aspx
They also make an MK210, but it's 2 5Amp banks. Stated differently, they added a second set of wires to an MK110.

[Hot Runr Guy]

Would that be the MK110 you're referring to? It has 1 bank @ 10Amps. and is around $90.00Cdn.
http://www.minnkotamotors.com/products/battery_chargers/portable_chargers/mk110p.aspx
They also make an MK210, but it's 2 5Amp banks. Stated differently, they added a second set of wires to an MK110.
Boat nut,
Darin was confused, he was trying to ask me about the 24V digital gauge I posted.
HRG

[boat nut]

Boat nut,
Darin was confused, he was trying to ask me about the 24V digital gauge I posted.
HRG

Ah, I was wondering.

By the way guys, a good insurance policy against cranking battery failure is to carry a set of booster cables long enough to get from a trolling motor battery, to the cranking battery. saved me a couple of times.

[colt100]

It does sound like the charger you have is not one of the better "onboard marine chargers." I would second the Dual Pro chargers. Also, if one of your batteries is new and the other is two years old, I think most would say that's not a good thing, either. However, if you had them both load tested and find that they're both perfect, maybe you'd be okay. I'd grab two new deep cycle batteries of your choice and make sure you're putting a decent charger on them...

I only have a 12 v trolling motor battery and a starting battery. That is why one is 1 year old and the other is 2 years old. I'm assuming that you thought that I was running a 24 volt system? Is the pro charger an on board charger? Can it be hooked up to both the starting and trolling motor batteries? My trolling motor battery is up front and the starting battery is in the back. Will I have problems installing the charger because of the distance? Anything else I should know about on board chargers?
Thanks for the replies.

[Derwood]

darin is often confused....

[Cape Cod Basser]

I have Minnkota chargers. I keep them plugged-in 24/7 during the season. They're quiet and cool to the touch. In the off-season I'll plug in the chargers once a week. I've had dual Pro's. They worked well, but they were noisy when they kicked-in . They didn't get hot, but they'd get pretty warm at times. I like a deep cycle battery with a high CCA/MCA number as opposed to a pure cranking battery. Unless you have a battery strictly devoted to cranking, most likely your cranking battery will be running a lot of peripheral electronics that will be drawing down its power during a full days fishing. Deep cycle batteries are better suited for the constant draw-down/re-charge cycle.

I see a lot of guys who run everything on a pure cranking battery and don't regularly re-charge that battery. Some guys don't even have it hooked to the on-board charger. They always seem to have problems at the end of the tourney day. I plug in my chargers immediately upon pulling into the garage. I do it before I un-hitch the boat!

[bob1]

My Dual-Pro 3 bank charger has one lead that is 21 feet long. Installed by Ranger on my Reata 1850 beacause the 2 trolling motor batteries and charger are in the front of the boat and the starting battery is in the rear. The 21 foot long lead goes back to the starting battery.

Bob