Dual Battery Charger

What is everyone using? I'm contemplating buying this one.

The Battery Tender 2-Bank charger is a top of the line 12 volt 1.25 amp charger/maintainer using the BT Plus recharge profile. The BatteryTender 2-Bank uses micro-processor technology in a four stage charging profile to charge, improve, and float your battery so it is ready when your are. Constant current charging and regulated voltage patterns allow the battery to be recharged fully and safely without the fear of overcharging. The real bonus is that the 2-Bank is capable of charging two batteries at once.



http://ecx.images-amazon.com/images/...RL._SS500_.jpg

I use two $10 battery trickle chargers from Harbor Freight. Four years now and never an issue.

Clark
I have that exact charger. I like it alot. Works great. I bought it on ebay. Lots cheaper.

This is what I use. I have had no problems at all with it.

http://www.promariner.com/productFea...oductNum=42012

Quote:

---

Originally Posted by tazz3069

Clark
I have that exact charger. I like it alot. Works great. I bought it on ebay. Lots cheaper.

---

Thanks Tazz. I ordered one today.

While were on the Battery topic and Clarkro2 ordered his so i wont be thread jacking hee hee.

I know you should store the batteries on the ground and on wood base, as concrete drains the battery. As for charging it or trickle. Do i just need to toss a charger on it for a few days every month or so?

I have never stored batteries before. Im my cars id leave them in it and start the car once a month and run it for a hour or so to get the engine and fluids going and charge it back up.

I want the batteries to last seeing how there 2 of them and there not cheap.

What I have done with my Travel Trailer and Boat is charge them completely and then disconnect the batteries so nothing is pulling a charge from them. I then just leave them on the Trailer or in the Boat all winter. We don't get real cold in the winter here in Seattle either.

Quote:

---

Originally Posted by 98outback

This is what I use. I have had no problems at all with it.

http://www.promariner.com/productFea...oductNum=42012

---

That's what I'm going with but I'll be getting the 3 bank charger for 3 batteries. The. Battery Tenders are maybe ok for the starting battery but does not do enough to properly charge a deep cycle battery such as an extra battery for stereos. You need to look at 20amp + chargers. The 7amp Ctek do fine for starting batteries and can charge a deep cycle but not one that has been completely discharged and bring it all the way back up. A strong charger is crucial for the life of deep cycling batteries to last seaon after season. Also, you need to do some homework as far as what type of battery you choose. I've made the decision to go with two Deka AGM batteries for the sound system. Each is a group 27 battery with 92 amp hrs which will give me 180 amp hrs which will be more than enough for me to play my stereo all day if I wanted. I'd rather have surplus power vs not enough to have clean, deep sound.

I disconnect mine and just let them sit all winter. in the spring, i throw them on a heavy duty charger for a couple of days each and good to go.

In regards to batteries. Be careful when not having them on a trickle charger when not in use for a long period of time. All batteries are different. All batteries have a discharge limit. Some are at 50%, 60%, 70%, and so on. That means that the charge in the battery can not go down below that percentage. If it does, it shortens the life of the battery. Also, if it goes below the allowable discharge, The battery can no longer hold a charge or hold the charge for a very short period of time. I go over these calculations when I install battery banks for solar chargers for solar panels. I ran into this problem with my motorhome this past summer. I let the batteries go past its discharge and the batteries were crap. Had to buy two new batteries at 185.00 a piece. Now I take all of them out and put them on a trickle charger.

Tazz that is exactly the reason i pull them and they sit on 1 amp tricklers all winter.

I'm looking into a used OBV that has dual batteries and I'm looking for some overview on the battery maintenance required. Over the winter the boat will likely be in a barn/garage that is not insulated. During the season we'll obviously try to use as much as possible but I'm sure there will be stretches of 2-3 weeks where we won't have a chance.

For the winter is the only thing I need to do is pick up 2 1 amp trickle chargers (whatever google finds?), bring the batteries inside and stick them on the chargers full time all winter (while not sitting on concrete)? Or do I need something more involved?

Then during the season what should I be doing in regards to battery maintenance? Should I be looking to set up some sort of regular charging (but I'm assuming not plugged in any time I'm at home?) Do I just go back to the trickle chargers any time it will be more than a week or so between uses? Or what?

I've never owned a boat (just a user for a long time) so trying to get started on the right foot. Thanks

Putting them on the trickle chargers during the off season is all you need to do. If your taking it out every 2-3 weeks during the boating season then you really don't need to do anything as long as your batts fully charge while out. Charging them between outings won't hurt and if it makes you feel better about it then definitely do it.

So something like this? (float vs. trickle)

http://www.harborfreight.com/cpi/cta...emnumber=42292

Those are exactly what i use and they do the job. May not be fancy but they keep the batts charged over the winter.

Perfect, thanks.

IF you plan on upgrading the stereo system in the future to like 3 amplifiers and 2+ stereo batteries or running your one stereo battery down often, then you need to look into a Pro Mariner type charger. Those Battery Tenders do not have the amps to fully charge a discharged battery. You'll need to look into something that has 20+amps.

I just have one battery in my boat and I have one of these hard wired to the battery terminals. I have an extension cord plugged in to the ceiling above the boat in the garage and if I am not going to use the boat for an extended period, I plug the charger in. Very convenient and works great.

http://store.schumachermart.com/se-1-12s.html

http://ep.yimg.com/ip/I/yhst-85105415359236_2062_24871

would one of those work for a dual battery settup? Would you need 2 or how would you wire it in?

Quote:

---

Originally Posted by viking

would one of those work for a dual battery settup? Would you need 2 or how would you wire it in?

---

Unless it's a two bank charger, then you'll have to get 2. I just ordered a Pro Mariner 3 bank charger for my 3 batteries

Quote:

---

Originally Posted by viking

would one of those work for a dual battery settup? Would you need 2 or how would you wire it in?

---

viking,

No, I thinking they only work for one battery. Amazon sells them for $30 each, free shipping, so you could buy two pretty cheap.

Or you can buy the dual bank trickle charger below for $99 @ http://www.batterystuff.com/battery-...l/GU2607A.html

Disclaimer: I don't know anything about this charger, just doing a little shopping for you :)

http://www.batterystuff.com/images/p..._series_lg.jpg

Finally picked up the boat today after having them install a dual battery. They put in the perko switch and installed a buss bar. Dealer said there is no need to put them on the charger since the PERKO switch is in the OFF position. Wonder what everyone thinks of that?

btw - had some gelcoat work done and it came out looking brand spanking new.

A battery will start discharging the minute it no longer is receiving a charge. It sits long enough and you have a dead battery. Every battery should receive a maintenance trickle charge if it's sitting for longer than a few weeks. Over the winter they should be hooked to a charger(s) while the boat is stored. I prefer out of the boat in my garage. Your dealer should know this and should have informed you off that.

Quote:

---

Originally Posted by Razzman

A battery will start discharging the minute it no longer is receiving a charge. It sits long enough and you have a dead battery. Every battery should receive a maintenance trickle charge if it's sitting for longer than a few weeks. Over the winter they should be hooked to a charger(s) while the boat is stored. I prefer out of the boat in my garage. Your dealer should know this and should have informed you off that.

---

He said during the winter he usually just removes the cables. I think I may pull the batteries and keep them at home on the charger.

I agree 100% with what Razz says.....

Do not listen to the dealer. Let me give you and example. In my motorhome, I have three batteries. 1 12volt for the main and 2 6volt for the coach. I do have a shut off switch for the batteries. The one for the 6 Volts is ran off the main battery. Then I have a manual switch for the for the main. My motorhome is completely dead now. After about 3 or 4 months later, I go to get it ready for a trip. I turn on the main battery and then the switch for the coach batteries. Nothing happens. The batteries are completely dead. They were so dead that they would not hold a charge and I had to buy neww batteries all the way around. Get the trickle charger. Keep your boat batteries on them until it is used again. My boat is in the garage and on the charger right now. We came back from our last trip about 2 months ago. I forgot to put the trickle charger on the batteries. It took about a day and a half to bring them up to fully charge. The charger was off for about two months with the Perko switch off.

Now in regards to the motorhome, I had the dealer install a solar panel on the roof. I will never run out of juice now.

Just a few basics.

Flooded batteries can self-discharge by 3 to 4 percent a month. Storing batteries in a discharged state accelerates their decomposition. A short maintenance charger is a good idea on the starting battery since it is put up relatively charged, as part of a dual-bank set-up.

However, deep cycle batteries that are deeply discharged when the stereo is played at rest, deserve greater capacity charging in order to properly desulphate and condition. For this you would want a dual-bank multi-stage AC shore charger that has a charging capacity equal to or greater than ten percent of the total batteries' amp/hour rating. A smart dual bank charger that distributes its capacity on demand to the bank in need is also an advantage over a charger that limits the current to each bank.

A dual-bank charger has the advantage of aggressively restoring the stereo bank without overcharging the starting battery.

Extra battery capacity is a benefit because if you continually exhaust your stereo bank to empty (10.5 volts for example) you'll get fewer cycles than if you partially deplete the batteries.

Full restoration should take place immediately upon storage rather than waiting just prior to the next outing.

With big stereos and play at rest you dont want to be solely dependent on your alternator. Get the best AC charger you can justify. Do what the tournament fisherman do as they've been dialed into battery technology and maintenance forever. Imagine a 40 amp trolling motor fighting a head wind for 8 hours. Those guys have to maximize their batteries because when their batteries are dead they're finished fishing.

David
Earmark Marine

David, any specific charger recommendations for dual battery setups?

brian,

We usually begin with the Guest 2611A 10 amp dual bank charger (5 + 5).

But I really like the ProMariner ProSport 12 and 20 amp models. They may be a little less protected from direct exposure to water but since they're not potted they cool very well. And the distribution scheme will deliver the full capacity to the bank in need. The ProSport 20 is our best seller. Then we graduate up to the ProTech 1240iPlus and to Progressive Dynamics for 60 or 80 amp models. We've got detailed info on our website. Get with me about overall wiring schemes if you're interested.

David
Earmark Marine
[email protected]

David, is that a desulfating charger as well, or just a charger? and or what are your thoughts on desulfators?
thanks doug

Thanks, David! Would you still recommend an in-boat charger if the boat is stored in an unheated garage for the winter? Or would it be better to take the batteries out of the boat and use a stand-alone charger in a heated area?

doug,

Other than CTEK chargers which claim to use pulse technology, we don't have first hand experience with specialized desulphators. Sorry, I can't help on that one.

But on a sidenote, our approach to battery chargers has been formed by the engineers who design chargers for the leading manufacturers serving the boating industry, particularly fishing. The typical tournament fisherman is using three group 31s to drive their trolling motor. The engineers assert that desulfation, especially in deep cycle flooded batteries, is a function of having enough current capacity to chemically excite the battery. And, that this can't be done with a small maintenance/trickle/tender type charger.

We've seen that battery brands of all types tend to get blamed for poor performance and short lifespan when the true cause is an inadequate charger, no charger at all or a bad charging regimen.


Brian,

We're in Texas so the cold temperature is not a factor. You may need to get an answer on that from someone closer to home.

David
Earmark Marine

Quote:

---

Originally Posted by EarmarkMarine

brian,

We usually begin with the Guest 2611A 10 amp dual bank charger (5 + 5).

But I really like the ProMariner ProSport 12 and 20 amp models. They may be a little less protected from direct exposure to water but since they're not potted they cool very well. And the distribution scheme will deliver the full capacity to the bank in need. The ProSport 20 is our best seller. Then we graduate up to the ProTech 1240iPlus and to Progressive Dynamics for 60 or 80 amp models. We've got detailed info on our website. Get with me about overall wiring schemes if you're interested.

David
Earmark Marine
[email protected]

---

David,

I have two batteries in my boat, one is the stock battery that starts the engine and runs the engine accessories, and the other is Kirkland Group 27 battery rated at 750 MCA, 600 CCA, and 115 amp hours that runs two amps, a Kicker 700.5 and a JL Audio M6600. I would like to install an onboard battery charger as I have found that our "float and listen to the stereo time" is much greater than our "engine running while boarding & surfing time" so that the stereo battery does not fully recharge just from the boat's alternator.

So my question is, will the ProMariner ProSport 12 Gen 2 be adequate for my application? I think the start battery is pretty much being charged fully by the alternator or close to it so when I plug the ProSport 12 in when I get home, it should send most of the 12 amps to the stereo battery which is in keeping with your guidelines of 1 amp charger output per 10 amp hours of battery capacity for choosing a battery charger.

Please advise.

Thanks,

Al

Al,

My statement is predicated on collective amp/hour rating, not singular. The ProSport 12 could get you by but the 20 is a better choice.

After a protracted period at rest your stereo battery may be fully depleted and could potentially pull 25 plus amps initally. Your boat pulls 15 amps to run without DC lights. Your stereo may draw 50 amps. If your alternator isn't running at a high rpm its not generating anywhere close to its full capacity. If the total demand exceeds the alternator supply then the stereo battery and starting battery will level to some degree. So you may not be putting your boat up with the starting battery topped off.

The real determining factor is your individualized usage. If you frequently run your stereo battery below 12 volts then step up to the 20.

David
Earmark Marine

David,

Thanks for the reply. What is the advantage of going with the 20 vs the 12? I understand that the 20 will charge the battery faster than the 12 but what is the advantage to charging the battery faster?

Thanks,

Al

Al,

I don't consider faster charge time the issue. Its irrelevant mostly.

As you discharge a battery, the sulphates leave the solution and bond to the surface of the lead plates. As you recharge, the sulfates return to the solution for a concentrated sulfuric acid. When you undercharge or leave the battery discharged for long durations, the sulfates tend to bond permanently. Once the sulfates are permanently attached to the plates the battery may heat up, take a surface charge but won't accept a deep and lasting charge. Thus, a shortened playtime at rest and shortened overall lifespan.

It takes a prescribed amount of current (10 to 13 percent of amp/hours) to chemically excite a battery in order to properly desulphate and condition.

David
Earmark Marine

Quote:

---

Originally Posted by EarmarkMarine

Al,

I don't consider faster charge time the issue. Its irrelevant mostly.

As you discharge a battery, the sulphates leave the solution and bond to the surface of the lead plates. As you recharge, the sulfates return to the solution for a concentrated sulfuric acid. When you undercharge or leave the battery discharged for long durations, the sulfates tend to bond permanently. Once the sulfates are permanently attached to the plates the battery may heat up, take a surface charge but won't accept a deep and lasting charge. Thus, a shortened playtime at rest and shortened overall lifespan.

It takes a prescribed amount of current (10 to 13 percent of amp/hours) to chemically excite a battery in order to properly desulphate and condition.

David
Earmark Marine

---

Thanks David, that's the answer I was looking for.

David,

I have the Blue Sea Add A Battery ACR installed - any compatibility issues between it and the ProSport 20?

Thanks,

Al

Hey Al,
I have the Blue Seas add-a-battery too. Been charging my batts seperately while still in the boat. I noticed that when I have the switch to the "on" position that they Combine and the green LED lights up indicating so. That is pretty straight forward as it senses the charge and then combines for the process. It is the same when the engine is running and alternator is charging.

However, I switched it to "OFF" over the weekend to seperately charge them and the green LED still came on after a few moments indicating they were combined? I got a little puzzled? Any input?

Quote:

---

Originally Posted by viking

Hey Al,
I have the Blue Seas add-a-battery too. Been charging my batts seperately while still in the boat. I noticed that when I have the switch to the "on" position that they Combine and the green LED lights up indicating so. That is pretty straight forward as it senses the charge and then combines for the process. It is the same when the engine is running and alternator is charging.

However, I switched it to "OFF" over the weekend to seperately charge them and the green LED still came on after a few moments indicating they were combined? I got a little puzzled? Any input?

---

viking,

The battery switch does not turn off the ACR. You have one cable going from the ACR to one battery and another cable from the ACR to the other battery. Turning the switch to "OFF" does not change that so the ACR is still sensing the charging current and combines the batteries once the battery your charger is on reaches a certain voltage.

I have a resettable breaker on each cable so when I want to charge just one battery, I open the breaker on the cable for that battery. You should have a fuse where I have a resettable breaker so you can accomplish the same thing by puling the fuse. See pic below.

[IMG]http://i250.photobucket.com/albums/g...7/IMG_6512.jpg[/IMG]