more battery questions...and the confusion continues!

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carboncow

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Jan 9, 2003
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once again i'm confused in all the wonderful information out there on batteries. <br /><br />i bought a "bulk" charged that claims to be rated for deep cycle charging. my two deep cycles that have been out of the boat since october are still at 12.7v each, and i was hoping to charge them to avoid sulfation...<br /><br />the manual says to charge to 14.7v on their charger for a new deep cycle...who has the same or conflicting opinion as this? many online publications do not mention charging to a set rate, while others claim to stop at lower ratings...<br /><br />was my voltage already OK at 12.7!?!?! help!<br /><br />shawn
 
Boatist

Boatist

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Apr 22, 2002
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Re: more battery questions...and the confusion continues!

Shawn<br />A normal lead acid flooded battery fully charged should read 12.6 volts. It is the same for deep cycle or starting. Each cell is 2.1 volts and you have 6 cells for 12.6 volts. This voltage can very some with temperature. When you charge voltage should reach around 14.4 volts and drop to about 1/2 amp.
 
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boatingfool

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Nov 30, 2002
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Re: more battery questions...and the confusion continues!

Ck out this link <br />www.boatingabc.com<br /><br />There is a resident expert over there called Vista-Al.<br />He knows so much about batteries its scary!
 
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petryshyn

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Re: more battery questions...and the confusion continues!

carboncow<br />Charging your batteries as often as you can will reduce sulphation, promoting longer life. Charging until the battery voltage reaches 14.7 with any charger will not hurt a lead acid battery. The current will drop off to .1 - 4 amps when the battery is fully charged.....<br /> :)
 
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dmessy

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Jul 8, 2001
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Re: more battery questions...and the confusion continues!

everything you want to know about batteries...<br /> http://www.uuhome.de/william.darden/dcfaq.htm <br />Walmart has a great charger for deep cycle batteries that is fully automatic. I got it for $30 and was pleased to see the the only difference between Walmarts and Schumakers Ship to Shore Marine charger was a sticker (and a $60 price tag!). It is a 10 amp. charger and has the name "Everstart" on it. Check it out...
 
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carboncow

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Re: more battery questions...and the confusion continues!

dmessy, thanks for the link. i've reviewed it many times...and its one of those ones that confuses me at times...<br /><br />schematic. i think you're close to helping me. i am charging my deep cycle with a 10amp charger. the book says that when the Ameter drop sot 1/3 to 1/2 of the charge amp so this would be 3-5 of the 10amp. that it's done. as mentioned i'm at high 14v even 15.2v on my one battery...but the ameter never drops below 6amp. additionally, the one battery had slight liquid coming from the seal and was warm (not hot)...so i was on the verge of an over charge...<br /><br />what is your take on the ameter reading. do you agree from your previous comment that it should drop below 1amp when charged!!?!?<br /><br />thanks. it's a inexpensive bulk charger, new. it does not step down or auto shut off.
 
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carboncow

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Jan 9, 2003
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Re: more battery questions...and the confusion continues!

dmessy, i'm off to walmart to find that charge at a great price. i know i'm going to ruin a battery someday with my cheapo charger...that doesn't shut off.<br /><br />thanks.
 
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petryshyn

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Re: more battery questions...and the confusion continues!

carboncow<br />A fully charged battery will draw approx. .1-4amps when 14 volts is applied to it. Your charger isn't regulated, and the voltage is climbing as the battery comes up in charge. This climbing voltage is the downfall of cheap chargers. If you were electrically inclined, you could wire in a "light dimmer" in series with the power cord and make the charger adjustable. This would let you adjust the voltage to 14 and observe the current, which would reflect the "state of charge" level.<br />Another method is to purchase a cheap hyrometer and measure the electrolyte "specific gravity" and remeasure after an hour of charge. (be sure to wear safety glasses and use caution when handling acid/electrolyte)If the readings don't go up after charging for an hour, the battery is as high in charge as it will get. If the readings go up after charging for an hour, charge again and remeasure. Keep doing this until the readings don't go up any higher.... <br />If you're not comfortable with the above, buy a regulated charger..... :)
 
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carboncow

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Re: more battery questions...and the confusion continues!

why is the regulated charge not amping down further after charging? am i not there, or is just junk?<br /><br />is the regulated type (you speak of) a step down type? bulk, lower and trickle charge...or just shuts off at there right charge?<br /><br />the hydrometer idea is something i don't want to do, plus it's a maintaince free battery...no entrance...<br /><br />thanks for the input.
 
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petryshyn

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Re: more battery questions...and the confusion continues!

There are a multitude of different chargers on the market. The more you spend, the more automatic features you get. Cheap unregulated non-automatic chargers get the job done, but some interpretation is required. 6amp at 15.2 volts sounds fully charged to me. 12.7 volts across the battery (after sitting atleast 4 hours after being charged) also suggests fully charged if you're in a warm climate.<br />If the charger manual says to charge until voltage rises to 14.7, then they are calculating this on the fixed current the charger supplies. Go with it, and you'll be close enough.....If you hit 15.2, you are certainly charged sufficiently. Don't let the battery get warm to the touch. This is an indication of overcharging or defective battery.... :)
 
Boatist

Boatist

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Re: more battery questions...and the confusion continues!

Carboncow<br />There many types of chargers out there but even a non regulated trickle can over charge a battery. As the battery becomes charged it will take less current (AMPS) but on a non regulated charger when the battery requires less current the charger voltage will go up forcing the battery to take more current.<br /><br />What you want is a AUTOMITIC charger. There are many types but two most common are: 1. Charger regulates it voltage around 14.4 to 14.8 volts with this style as the battery charges up the current will be reduced to less than 1 amp on a good battery. 2. Another type the charger charges and when the voltage reaches 14.8 the charger shuts down, this type some times turns on a charge complete light.<br /><br />I like the first type better but either work pretty good. The key is to make sure automatic type not manual.<br /><br />Charge batteries at least once a month. A type of so called automatic charger I do not like is ones that just have a timer built in to a manual charger.<br /><br />For battery life I think the most important things is to recharge battery as soon as possible after use. Do not allow starting batteries to become run down below about 12 volts or deep cycle to go below 10 volts. Charge at least once a month when not in use. Use olny distilled water and keep water level to correct level. When add water always charge.<br />Good luck.
 
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carboncow

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Re: more battery questions...and the confusion continues!

Perfect guys! I think I got the info I wanted to read to help me!
 
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