Old batteries that don't hold a good charge

[J.A. Veil]

I am on my third 12V battery for my kayak's FF/GPS. I started with a 5 amp-hr battery. After a year or so, it would not hold more than 30 mins of charge. DaddyG gave me a 7 amp-hr battery after that. It performed well for a while but after 6 months it would not hold enough charge for a 3-4 hour trip. Last fall I bought a 12 amp-hr battery. Given the lousy and cold weather of late, that battery has seen little use so far.

I don't plan to keep the two older batteries around much longer. I am happy to give them away to anyone who is interested, but I don't know if there is any value to a battery that has limited charge capacity. Are there any methods to rejuvenate a used battery to make them hold a longer charge? If so, does anyone want these batteries?

[Turtle135]

That is odd that the battery is giving up the ghost that quickly. I have had a 12 volt 7 amp/hour sealed lead acid battery for more than 10 years. It is not uncommon for me to run my fish finder for 6-7 hours straight per trip. I generally do not recharge it until I have done 2-3 trips. How are you recharging those batteries? Wondering if there is something going on with your recharging system that is causing a shorter lifespan on the battery?

If you have any battery shops in your neighborhood they can recycle old batteries for you. A computer shop my be able to recycle as well as those types of batteries are commonly used in computer battery backup power systems.

[J.A. Veil]

Dave -

I have a small trickle charger in the garage. After each trip I hook the battery up and wait until the light changes from yellow to green. My FF/GPS is an older unit (~2008 vintage). I suspect it has a higher power draw than some other units.

[Turtle135]

That trickle charger is a 12-volt charger?

I admit, I am shocked that the battery I have been using has held up this long. It used to just power up a PiranhaMax (which probably does not draw a whole lot of power) but for the last two season it has powered a Humminbird 346C DI (a color unit) which does draw more power.

[J.A. Veil]

That trickle charger is a 12-volt charger?

I admit, I am shocked that the battery I have been using has held up this long. It used to just power up a PiranhaMax (which probably does not draw a whole lot of power) but for the last two season it has powered a Humminbird 346C DI (a color unit) which does draw more power.

The trickle charger is a 1.5 amp unit that has settings for 6v and 12v. When batteries are new, it easily brings them back to full charge. Once they are full again (green light), I disconnect the batteries from the charger. I try to start each trip with a fully-charged battery (not necessary with the new 12 amp-hr battery). I could tell the older batteries were wearing out when the FF/GPS unit would shut off after 1-2 hours. I could restart it and watch the voltage on the screen quickly drop from >12v to 9v. At that point, it would shut off again.

[Jaspratt]

If its a trickle charger, why not just leave it on until your ready to fish. You will probably have better run time doing that.

[Cowpokey]

Have the bad batteries been abused at all? Might have dropped a cell. Put a volt meter on them and see what it reads. Should be 12 volts or more if they are good. A 12Vdc battery has 6 cells, each cell is +2Vdc. If it reads 10Vdc or less the battery is no good for normal use. If they are lead/acid batteries they could be reused (after proper procedures) to be melted down and poured into a jig mold.

[kevinfry]

John, I was told that type of charger was sure to ruin these type of batteries. the right charger (I chatted with rep at battery warehouse to get the right one) was far cheaper than the one you are describing (car battery trickle charger). it looks like a charger you might use for a hand held VHS radio but with alligator clips.

[archeryrob]

With multiple batteries dying and developing memory, your charger is the problem. A normal 12V battery will read over 13V on an volt meter when charged. When they start reading around 12V they are not charged all the way or damaged.

http://www.pwrman.com/faq/can-a-batt...mage-a-battery

Also make sure you have a "smart" charger which is microprocessor bases and not just a cheaper zener diode trickle charger. The ones using the term float charge are usually better.
http://www.batteryspace.com/leadacid...sfloating.aspx

[HJS]

Yeah, I agree with others. There is something terrible wrong somewhere in your system. Anywhere from a 2 bad batteries right from the get-go (highly unlikely) or an inappropriate charging system or method of charging.

The 8amp battery I use on my old b/w FF is about to start it's 3rd year of use. It still holds 12+ volts after several hours of use.

IMHO, these small batteries are too small to be left on trickle-charge for any more then a 3-4 hours. I use an ancient 35 year old charger (Made in USA) that actually has an old-style amp out-put meter. When I first put my FF battery on charge, after several hours of use, the amp meter reads about 1.5 amp . After about 3-4 hours of charging the amp meter has slowly dropped back to about 0.2 amp. That's when I take it off.

FF Battery.jpg

[JKay]

I bought a good smart charger years ago for about $85. Not cheap, but I've used it to charge the battery for my old bass boat, and now use it for my fish finder batteries. I've always had unbelievable battery life and have attributed most of it to this charger. I think it is a Schumacher.

[archeryrob]

You will not need a $85 charger to charge a 4ah to 7ah battery. You did need it to charge your 75ah battery you used on your boat though.

[JKay]

You will not need a $85 charger to charge a 4ah to 7ah battery. You did need it to charge your 75ah battery you used on your boat though.

True. I bought it originally to charge the battery on the bass boat.

[OVERBOARD]

Another thing i try to avoid is storing the battery fully charged.. It's not a good idea to charge it right back up as soon as you get in and then let it sit that way until you go out again.. Most manufacturers will tell you to leave the battery somewhere around half charged when it's going to sit for any time.. I usually bring it out of the boat and leave it on a shelf indoors, and then charge it the night before I'm heading out. If i run it completely dead I will charge it for an hour or two and then shelf it..
Same goes for radios and gopro's don't let them sit either fully charged or dead...

[dsiekman]

With the two dead batteries, try smacking them on a hard surface several times on each side. Not hard enough to damage the case, but just a good whack. Sometimes that will knock the oxidation off the plates and buy you a little extra time.

Do this at your own risk. I am sure the manufacturer would never recommend it. These are similar to the batteries in security systems and Fios boxes. I had a phone tech tell me out this several years ago. It worked for me.