I messed up...dead deep cycle

[chris in va]

It reads 3.6v. I accidentally left the cables connected over the winter.<br /><br />This battery serves to start my engine and run some electronics. I haven't tried charging it yet. Time for a new one?

 

[cobra 3.0]

Re: I messed up...dead deep cycle

See if it charges to full. The next test is to see if it craps out after a few cranks (under load).

 

[JB]

Re: I messed up...dead deep cycle

Charge it slow, 2-4amps for several days.<br /><br />Test for charge with a hygrometer (tests the specific gravity of the electrolyte). Don't accept voltage readings as indicating state of charge. <br /><br />It should be okay.<br /><br />Good luck.

 

[ZmOz]

Re: I messed up...dead deep cycle

Hey Chris! I didn't know you were a member here...

 

[18rabbit]

Re: I messed up...dead deep cycle

Charge it slow…

Bulk charge at 25% of the 20-hr a/hr rating for the battery.<br /><br />I was under the impression bulk charge should be a min of 25% and max or 40% but someone in another thread posted a link to a great faq that stated max 25%, but showed a graph at 40%. Either way, the faster you get a charge back into the battery, the better for the battery. You are right about blowing off the meter reading and going with a hydrometer.

 

[Boatist]

Re: I messed up...dead deep cycle

Chris <br />I think you will be very lucky if the battery will charge up. The chances are better with a deep cycle battery so for sure charge it up. I would use any automatic charger under 20 amps. If you do not have a automatic charger still charge it right away but keep a close eye on the voltage. When it reaches 14.8 volts then it should be good. If it is not a sealed battery then checking with the hydrometor is a good idea. Also load test by turning everything on and try and start the motor. Keep a eye on the voltage for a few days and see what happeneds.

 

[ThomWV]

Re: I messed up...dead deep cycle

I agree with Boatist completely. You'll be very lucky indeed to see it take a charge and even if it did I wouldn't trust it as far as I could toss it - not very far for a 50 pound battery.<br /><br />If you've got a smart charger hook it up and hope for the best but if you use your boat on open water without a lot of help in sight (so they can see you wave your arms around, because your radio is going to be worthless) replace it.<br /><br />For whatever its worth West Marine used to have a section in some of its older catalogs where they went on and on about how good one of their products was. It was the only product they ever singled out for this type of praise. It was the StatPower TrueCharge 20 battery charger. They connected it to a deep cycle battery that had been sitting, dead as a doornail, for over a year and the thing was successfully recharged after a couple of days. Please understand that the TrueCharge 20 is the best small boat on-board charger made, and they are not cheap at all. What they didn't say was if they trusted that restored battery out on the water - I wouldn't have.<br /><br />Thom

 

[ZmOz]

Re: I messed up...dead deep cycle

ThomWV - It shouldn't be that hard for you to "trust". If it charges up, and he tests it to see if it will run his electronics it will be just fine. The capacity has probably decreased, but it's not going to suddenly just go completely dead on the water for no reason. And I'd be willing to bet that it will take a charge just fine, I did that more than once to the starting battery in my old truck, and it still worked just fine. I'm sure it wasn't as good as it could have been, but I never noticed anything bad about it. And this is a deep cycle, there are LOTS of people who purposely run them completely dead every time, because they think it will develop a memory if they don't. I remember posts by at least 2 different people on this board that would attach a light to the battery and leave it until it went out before charging. Certainly not good for the battery, but they didn't kill it either.

 

[ThomWV]

Re: I messed up...dead deep cycle

We fish off shore, tipically 40~50 miles from land. I do not take chances with my boat or its systems. If you operate in a place where you have the luxury of trusting equipment that has already failed that is a good thing. I do not.<br /><br />The problem he faces isn't that it was run completely down, its that it remained in a discharged state for what appears to be a long time. That is the absolute kiss of death for a lead acid battery.<br /><br />The memory effect you spoke about is one that some folks think takes place with NiCad batterys. Its a myth but the myth goes like this; repeated discharges to some level or repeated recharges to less than 100% causes the battery to only be able to operate within that range. Is pure bullhocky, but a lot of people believe it. In no way is it true of lead acid batterys though. For whatever its worth I read a study commissioned by NASA a couple of years ago about memory in NiCads. The memem that suggested they had memory was causing NASA to put backup batterys in earth orbiting satellites. The ones that actually orbit have an absolutly exact cycle of charge and discharge, right to the second, and if any batterys are going to have memory and suffer from it those are the ones. So at great expense the extra weight of backup batterys was being sent up. Then it occured to someone at NASA to check and see if batterys really did have memory. It turned out that they were unable to cause any battery to develop mememory. That was a very good thing because that finding allowed them to reduce payload weight by removing redundant batterys (this was in unmanned craft, like spy satellites). Of course now days the greater power density of the Li-Ion batterys has caused NiCads to be abandoned in weight conscious applicaitons but none of that has anyting at all to do with our lead acid batterys, I just thought it would be of interest to you.<br /><br />Deep cycle batterys are designed to be able to withstand repeated discharges to about the 50% level. Go lower than that and even they suffer greatly. The loss they suffer is in available cycles generally but a loss of output power is usually also associated with over discharging.

 

[ZmOz]

Re: I messed up...dead deep cycle

Originally posted by ThomWV:<br />We fish off shore, tipically 40~50 miles from land. I do not take chances with my boat or its systems. If you operate in a place where you have the luxury of trusting equipment that has already failed that is a good thing. I do not.<br /><br />The problem he faces isn't that it was run completely down, its that it remained in a discharged state for what appears to be a long time. That is the absolute kiss of death for a lead acid battery.<br /><br />The memory effect you spoke about is one that some folks think takes place with NiCad batterys. Its a myth but the myth goes like this; repeated discharges to some level or repeated recharges to less than 100% causes the battery to only be able to operate within that range. Is pure bullhocky, but a lot of people believe it. In no way is it true of lead acid batterys though. For whatever its worth I read a study commissioned by NASA a couple of years ago about memory in NiCads. The memem that suggested they had memory was causing NASA to put backup batterys in earth orbiting satellites. The ones that actually orbit have an absolutly exact cycle of charge and discharge, right to the second, and if any batterys are going to have memory and suffer from it those are the ones. So at great expense the extra weight of backup batterys was being sent up. Then it occured to someone at NASA to check and see if batterys really did have memory. It turned out that they were unable to cause any battery to develop mememory. That was a very good thing because that finding allowed them to reduce payload weight by removing redundant batterys (this was in unmanned craft, like spy satellites). Of course now days the greater power density of the Li-Ion batterys has caused NiCads to be abandoned in weight conscious applicaitons but none of that has anyting at all to do with our lead acid batterys, I just thought it would be of interest to you.<br /><br />Deep cycle batterys are designed to be able to withstand repeated discharges to about the 50% level. Go lower than that and even they suffer greatly. The loss they suffer is in available cycles generally but a loss of output power is usually also associated with over discharging.

The point is, if the battery is charged, working, and tested, there is nothing to worry about even in the middle of the ocean. It's not going to suddenly go poof and die. I know it is nicd's that are associated with memory problems, but many many people that don't know better think it applies to all rechargeable batteries. And yes, it is true for some nicds in some conditons, it is not a complete myth. I myself used to think that about lead acids. I have a portable jump starter that has a sealed lead acid. It also has a built in flashlight, I would turn on the light and leave it on until it went out before charging. Often I would leave it completely dead for months at a time like this. I know now that it is very bad to do that, however, the battery still jump starts big engines just fine and has quite a bit of capacity remaining. <br /><br />Chris - charge it up, see if it still works. If it does don't worry about it ever again. It will have a decreased capacity, no doubt about it, however, it will probably only be 1-2 amp hours, which is nothing to worry about.

 

[Boatist]

Re: I messed up...dead deep cycle

ZmOz<br />Certinly he should charge it up with a good charger and load test it. If it recovers then he should keep an eye on it for a while before trusting it too much. At 3.6 volts he did not even have 2 cells with any voltage. I do not know how cold it get in his location but a totaly discharged battery can be frozen and damaged also.<br /><br />I remember lots of post from guys who discharged their deep cycle all the way also, but as I recall most of them also said batteries only lasted 6 month to one year.

 

[waterinthefuel]

Re: I messed up...dead deep cycle

Discharging batteries does help prevent them from developing a memory. You don't have to drain them ALL the way down, but when your trolling motor starts sounding like its apologizing every time you hit the go button, it's time for a recharge. <br /><br />I've dealt with hundreds of rechargable batteries from remote control airplanes and cars to golfcarts and marine batteries. They all are basically the same, run them down to almost dead (completely dead for the r/c cars) and recharge fully. This doesn't hurt batteries that are designed for it. I have a trolling motor battery that I've discharged down to almost zilch and I don't even know how old it is, I'm going to guess between 6 and 8 years. I've had the boat for that long, and bought two identical batteries brand new, one was used to start the engine and stayed fully charged, the other was used on the trolling motor. Well, the one to start the engine has long since gone kaput but the trolling motor one is still going very strong. It was almost gone and I reconditioned it using a smart charger, and now its like new again. Car batteries are not designed for a full discharge, but deep cycles are. But they must be quickly recharged, not allowed to sit in an uncharged state for months at the time.

 

[ZmOz]

Re: I messed up...dead deep cycle

Originally posted by waterinthefuel:<br />Discharging batteries does help prevent them from developing a memory. You don't have to drain them ALL the way down, but when your trolling motor starts sounding like its apologizing every time you hit the go button, it's time for a recharge. <br /><br />I've dealt with hundreds of rechargable batteries from remote control airplanes and cars to golfcarts and marine batteries. They all are basically the same, run them down to almost dead (completely dead for the r/c cars) and recharge fully. This doesn't hurt batteries that are designed for it. I have a trolling motor battery that I've discharged down to almost zilch and I don't even know how old it is, I'm going to guess between 6 and 8 years. I've had the boat for that long, and bought two identical batteries brand new, one was used to start the engine and stayed fully charged, the other was used on the trolling motor. Well, the one to start the engine has long since gone kaput but the trolling motor one is still going very strong. It was almost gone and I reconditioned it using a smart charger, and now its like new again. Car batteries are not designed for a full discharge, but deep cycles are. But they must be quickly recharged, not allowed to sit in an uncharged state for months at the time.

I'm sorry, but NO lead acid is designed to be completely run down, nor is there ANY memory effect on them. If you do it a few times you're not going to notice anything, but it is FAR from good for them.

 

[waterinthefuel]

Re: I messed up...dead deep cycle

Uh, didn't I say in the second sentence not to run them down ALL the way? <br /><br />The memory effect is stronger in NiCD and NiMH, but it happens. It happened to our golfcart. It was kept fully charged, and the batteries didn't last but 2 years. The cart we had at work was drained down repeatedly every single day and those batteries have lasted half a decade.<br /><br />I'd love to know where you get your information from, read up on deep cycle batteries. That's why they are called that, they have a deep cycle....well an ability to hold a strong charge and take strong discharges over and over. <br /><br />I've done it to mine hundreds of times, don't tell me it hurts them. No, I don't go ALL the way down. But I've gone until voltage gets to 10.5 to 11 sitting, but under a load it goes to about 3. Its the perfect time to recharge, you are down almost all the way, and the battery won't be harmed by doing it. I get at least 5 years out of all my batteries, so if I'm damaging them you'll have to remind my batteries to act damaged.

 

[Ralph 123]

Re: I messed up...dead deep cycle

Discharging batteries does help prevent them from developing a memory

That is very true for NiCads but not for Lead Acid cells. NiCads benefit from being deeply disharged and recharged. Deep discharging of lead acids damages them.<br /><br />Here is a good site about lead acids:<br /> http://www.uuhome.de/william.darden/carfaq.htm <br /><br />

<br /><br />14.12. Lead-acid batteries have memories.<br /><br />Lead-acid batteries do not have the "memory effect" mistakenly identified with first generation Ni-Cad batteries; however, continuous undercharging will lower the capacity of the battery over time. Deep discharges below twenty percent State-of-Charge (approximately 12.0 volts) can damage batteries and will shorten their service lives.<br /><br />11.2. If possible, recharge a Deep Cycle battery every day it is used and as soon as possible after each use. When not in use, maintaining the battery's State-of-Charge at 100% by continuous float charging is best way to prevent permanent lead sulfation. If continuous float charging is not possible, recharge before the State-of-Charge drops below 80%. Permanent sulfation kills approximately 85% of all Deep Cycle batteries.<br /><br />11.3. Reducing the average DoD (Depth-of-Discharge) by proper Deep Cycle battery sizing will significantly increase a deep cycle battery life. For example, a battery with an average of 50% DoD will last twice as long or more as an 80% DoD; a 20% DoD battery can last five times longer than one with a 50% DoD. Golf cart batteries will typically have an average 225 cycles at 80% DoD and 750 cycles at 50% DoD. Avoid DoDs that are greater than 80%. The "sweet spot" (optimum DoD for the greatest amount of power produced over the service life) is generally somewhere between 20% DoD and 60% DoD. For the AGM battery below the "sweet spot" is approximately 22.5% DoD.<br /><br />11.4. Never discharge below 10.5 volts. An adjustable low voltage disconnect set for an 80% DoD or less can limit the maximum Depth-of-Charge and protect the batteries and electrical appliances. Leaving your lights or other accessories on and fully discharging a Car battery can ruin it, especially if it is a sealed, wet Maintenance Free (Ca/Ca) type or it is frozen. If this should occur, you should let your battery thaw, if frozen, fully recharge it with an external charger, remove the surface charge, and test the battery and charging system to determine if there is any latent or permanent damage.<br /><br />

 

[18rabbit]

Re: I messed up...dead deep cycle

The closest thing to memory effect in a lead-acid deep cycle battery happens when the electrolyte is initially added to a dry battery. It may take 3-7 days for the chemistry to equalize. Everything is down hill from there. There is no ‘memory’ effect in lead-acid batteries, only loss of capacity due to internal damage to either the lead plates or the soup. The soup is arguably correctable; repairing the plates is not…although batteries are recycled.<br /><br />Once the electrolyte is added to the battery, the clock is started. There is nothing you can do to stop it or slow it down. You can only get the most use of the battery before it’s death. Using the battery is a trade off between detrimental effects, all of which exacerbate the chemical process that results in the decay of the battery.<br /><br />My guess would be the golf cart batteries died an early death from a loss of lead surface area. Either deeply discharged and left that way (coated) or consistency over charged (eroded). Fwiw, GC batteries are some of the most durable common batteries you can get your hands on. They out perform most 12v deep cycle batteries used for trolling motors and are almost always a better choice for that application. They’re just not ‘convenient’.<br /><br />Not all batteries are created equal. For the most part, the more expensive a batter is, the thicker the internal plates, the deeper the discharge profile, and the longer the battery life. When comparing two batteries, you need to get hold of the manufacturer’s specs and compare the plate thickness, lest you compare apples to oranges. Also, when you start venturing outside the normal 12v off-the-shelf batteries, the 20-hour load spec is not necessarily used buy all manufactures. It is not always easy to compare batteries at first blush.

 

[gaugeguy]

Re: I messed up...dead deep cycle

Originally posted by waterinthefuel:<br /> so if I'm damaging them you'll have to remind my batteries to act damaged.

Here's your reminder...Waterinthefuel's batteries, act damaged<br />

 

[ZmOz]

Re: I messed up...dead deep cycle

Originally posted by waterinthefuel:<br />The memory effect is stronger in NiCD and NiMH, but it happens.

Let me say this one more time. The only batteries that have a memory effect are NiCd. And even then it is much more minor than many people believe. It does not happen in lead acid, or NiMh. Not even a little. Not even a really really little bit. Also the life of a lead acid is directly related to the depth of discharge. If you only discharge a battery by 5% it will last thousands of cycles. If you discharge a deep cycle by 95% every time it might last a few hundred. You can find this exact information published on any manufacturer's website.

 

[LubeDude]

Re: I messed up...dead deep cycle

Stay Hard OZ, Im on your side.

 

[Boatist]

Re: I messed up...dead deep cycle

Lead acid batteries Have NO MEMORY.<br /><br />The sooner you recharge it to full charge the better for the battery.<br /><br />The longer you wait to charge it and the farther you run it down the sooner it will fail.<br /><br />Discharge a starting battery below 80 percent or a deep cycle below 50 percent and you will shorten it life. By the way 50 percent is not 6 volts it 12.2 to 12.4 volts.<br /><br />If Lead acid batteries had memories cars would not start on cold morning when you need more power to start than on the warm morning.<br /><br />It would be nice if CHRIS IN VA would come back and tell us how he made out.<br /><br /> http://www.uuhome.de/william.darden/carfaq.htm