I figured someone on here uses trolling motors and batteries and might help me out.

Although I use this for my camper, it still might apply.

A few weeks ago I bought a deep cycle/RV/marine battery from Sears for my small slide in camper. It is rated a 600CCA

When I put the charger on, the charger never goes below about 4 amps,no matter how long I leave it on.

My charger is an old Sears that only has 6&12 volts and no amperage switch.

I borrowed a neighbor's that has 2 amp, 10 amp, and 50 amp settings.
At the 2 amp setting it reads at about 3&1/2 amp, and never goes lower. If I set it on 10 amps, it goes to full charging setting.

Do these deep cycle batteries do this or did I get a lemon battery?

Thanks in advance,

Just checked another battery. Looks like the one I just bought is bad

Vince

If I understand this exactly as written, Mine do not work that way with my charger.

I have an on board charger on the boat, but I have a standalone charger that has a massive amount of setting for various batteries.

As an example when set to AGM, 12v, 15amp, 65deg, and then I select "current" it will go to 15.5 when it's near flat.

as the battery charges, the current will read lower and lower amps until it clicks to the display that says FULL.

It will not set at 3-4 amps forever. I'll say this though. When that thing is dead flat, it will charge from 15 plus amps in a couple hours to 3-4 amps, and that last 3-4 amps takes just as long as the first 10-20 amps did.

It takes a long time to get that last bit of power stuffed in there!

Oh Forgot to add, I have two of those big blue and white Sears AGM deep cycle marine batteries, they are the best batteries I've used for the boat and the trolling motor. Probably the same one you're talking about. Mine are likely 75 pounds each, I think they might be bigger then 600CCA? They are Size or class 31 batteries if that helps?

Thanks JJ, I had this one setting at 4 amps for maybe 8-10 hours. It never changed.

I am taking it back to Sears Monday to have them test it.

Thanks for the reply.

Vince

I have duell batteries on my boat with one being a deep cycle for the trolling motor. Portable chargers didnt work well for me so i installed an onboard charger which is always plugged in when the boat isnt in use. It maintains both batteries as needed.
I might add that i also have a 2000 model slide in camper on my
pickup which is rarly removed. It still has the original battery. No doubt it is no longer any good but so long as the
camper is connected to the pickup wiring harness everything works. Yes it does draw from the truck battery when im using the
12 volt lights in the camper. When the camper is plugged into a 110 outlet it charges everything anyway.
It works for me and it might work for you also. Otherwise id be considering an on board charger.

I have a dual battery Diesel Ram Cummins( 98). I have it wired fore and aft for winch operation that I can insert the winch onto a receiver hitch on either end. To operate the winch,I have a switch inside the cab that energizes a relay that opens a contact so that the winch connector has power. I plan to charge this battery when it needs it by activating that switch and I have a copper jumper cable coming from the winch connector to the battery.

In the cold months, you don't want to be drawing on the dual battery system for the diesel that is critical to getting it started.

Yep same situation with my boat. I have dual batteries with a switch. One for starting, one for "house" use. Don't wanna be 10-20 miles from the dock with no battery to start that big engine!

Although I have an 8hp honda trolling motor that can pull start, it would take a long time to get anyplace with that little bugger!

The selector switch is a different issue from charging.
You are correct in that they are a good thing to have for the
reason you mentioned.
No reason one cant be installed on a truck also so that the starting battery can be isolated.

The charging situation is not the same, only the selector was what was intended by saying I have the same setup in the boat as he has in his truck

Look into a 2 bank charger which will maintain both batteries.

Battery chargers are meant to do that. They'll charge at high amperage until it's about 80% full, then go to about 3 or 4% and maintain that. It won't ever truly be 100%.

Newer chargers anyway. Say maybe last 15 years or so. I think.

Here's what I've learned with my trailer. Use a charger if it's dead and you need to use today. Otherwise, use a tender. Totally different from a charger.

I use the actual Battery Tender brand. It'll take three completely dead deep cycle batteries and fully charge them in about three days. Then maintain a true 100% charge indefinitely. And it's a true charge.

The average battery charger will only give you about 85-87% charge and can set a memory in the battery. Tenders don't do this. But the upside to a charger is how quick you'll get that charge. So I keep both handy

Basically there are two types of chargers. The old style just put out a voltage greater than the battery full charge voltage. When the battery absorbs all the charge it can the high charger voltage keeps dumping current into the battery. The battery dissipates the current as heat. In doing so it splits water into hydrogen and oxygen. If the battery produces hydrogen and oxygen faster than it can recombine it vents and the battery looses water. This is why there are warnings to not overcharge with the consumer old style chargers. Full charge is typically when the charger is down to 3 or 4 amps. With some of the old high current chargers it was possible to dump more current than that into a charged battery. That could produce enough heat in the battery to warp the plates and destroy it.

The new style chargers are usually called automatic chargers. Automatic chargers monitor the battery's state of charge by measuring the voltage across the battery. When it sees a full charge voltage across the battery it drops into a current limiting mode. It will not send more current to the battery than it can handle without loosing water. This would've been too expensive to do in the era of old chargers, moderrn electronics makes it possible.

Now this doesn't happen all at once. If your charger has "charging" and "full" lights you'll see them start to blink back and fourth at some point. The battery shows full voltage, the charger drops to current limited mode. The battery absorbs the charge, the voltage drops, the charger switches back to the quicker charging voltage limiting mode. And back and forth. When the battery is about full the charger will show "full" more than "charging."

As a battery ages the full charge voltage becomes slightly lower so you'll see more of this back and forth even when the battery has absorbed all the charge it can. Also starting and deep cycle/gel cell fully charged voltages are slightly different. You want an automatic charger with a switch to select between deep cycle and starting batteries.

I still have an old style charger. The only time it gets used is when a battery is so far discharged that the automatic charger can't sense that it's connected to the battery. Once the voltage is up enough it goes on the automatic charger. That's about the only good use for the old style charger today.

Plus with an automatic charger you can turn it on and forget about it. Can't hurt the battery. For longest life batteries should be recharged right away. When I get back from a fishing trip I throw the charger on and don't think about it until some convenient time the next day.

Battery tender (minder)-type chargers are like automatic chargers in the current limited mode. They will only put out a current so low that it can't hurt the battery. So they take a L-O-N-G time to fully charge a depleted battery.

I probably need to get an up to date charger. Mine is 25+ years old. Strictly 6 or 12 v volts.

Worth it just for the convenience of not having to check it. My old one has yours beat, 30 years plus a little. Used it mainly to warm up the battery on below zero days when I was in school. Small car, small battery, and not much left after the cold sucked half the capacity.

Thinking back, it might be older. I have lived in CO for 40 years and bought it before that when I lived in Albuquerque.

In that case, it's time to upgrade. They're not expensive. What you've got now is prehistoric compared to what's out there.

Here's the battery tender website. Check out there information section on how batteries and chargers work. Even if you settle on a different brand, you can't beat their website for knowledge.

http://batterytender.com


It's what I use for batteries I don't use weekly. For a quick charge, I use the battery charging feature on my small generator. Just cuz I have it already and it gives the Gen something to do.

One of the best smart chargers for both automotive and deep cycle batteries:

http://www.amazon.com/Black-Decker-VEC1093DBD-Battery-Charger/dp/B000EJQJ1G

Spendy but worth the upgrade from those 30+ year old automotive only chargers.

Smart charging cycle for deep cycle batt's:

http://www.jackdanmayer.com/images/Electrical/batterychargestages.jpg

I picked up one today that is for deep cycle and auto batteries. Auto adjust to tender after a full charge, 15, 8 and 3 amp.

Spending $150 for a charger for a $129 battery is not in my sights at present.

Sure sounds like the charge is bad, I'd put it on a good battery to see if it backed off, if it doesn't on a charged truck battery then she's toast.

Cabelas has a great sale going now on AGM's.

I bought 2 today