Old-Biscuit wrote:
Buy a hydrometer and check each cells specific gravity YOURSELF.
I agree since there are good options for around $10 but many just are not going to deal with battery acid in a direct way and possible associated mess from dripped acid.
The volt meter can tell a lot but not as well as hydrometer (as we move to AGM batteries hydrometers are worthless however) or even many lead acid batteries on the market today with semi sealed cell caps or a load tester.
A fully charged 12 volt battery that sets overnight and reads less than 12.6 volts I have found is a junk battery. It it reads 10.5 volts there is a dead cell without question.
Over the years I have spent hundreds of hours trying to get more life out of FLA batteries with most of them being deep cycle (trolling/golf cart types).
It has been a waste of time in one way of looking at it.
If the charging system checked out OK then in 100% of the time where the battery(s) died they were DEAD no matter what I tried. I even did polarity reversing techniques that took a lot of time and efforts.
Summary: If a battery or bank of batteries fail to work and the CHARGING system and cables test to be healthy then the batteries will most likely be JUNK. If they are 3+ years old they were always JUNK. :)
Success in recovering run time of batteries in UPS (uninterrupted power sources) for computer server rooms has been positive however if voltage readings where normal after being fully charged then load tested for 10 seconds with 100 amp load tester on batteries with 75-150 amp ratings.
Example: I had four 75 amp hour batteries in a 48 volt battery bank UPS that would hold the standard server load for one hour. That run time dropped to 30 minutes after about a year. I used the Desulf mode on our B&D/Vector battery charger for three 24 hour cycles (more cycles did not help more) and got the bank to back up to 45 minutes of run time for nearly an extra year.
Recovering lead acid batteries I find is really a waste of time and can be messy IF the charging system and cables are good and clean.
NOW there are simple ways to make FLA batteries last longer if started when they are new/new like. The low brainer is to pick up a $20 maintainer at WM, online, etc and connect it when you shut off the charging source. One can expect 2x the battery life in most cases.
I like the automatic B&D/Vector chargers better than other brands we have tried BUT they will NOT fully charge a battery. Well the computer will state fully charged but they are not Fully charged I have found over and over again (close but not full). Their Desulf Mode feature is AWESOME however.
We have a few batteries where we do use 120v maintainers but we have cars, trucks and tractors where they are not really good options because of where they are parked.
This is my favorite Automatic charger due to Desulf Mode feature and it charges.If I could only have one charger this would be the ONE type I would want.This is the brand we currently have. It must be TOTALLY manual (NO computer controls)in my experience. If I put it on a healthy 12v battery in the 6 amp setting for 24 hours (typically overnight) the charging rate without fail will be down to 1 (one) amp reading on the meter and the output will be at 16+ volts per the B&D automatic charger that will be connected at the same time.
The B&D charger will be running in Desulf Mode if connected at the same time as the manual charger. This alone will help clean the plates but when added with the manual charger putting out 16 volts at one amp (equalizing mode results) the equalizing process helps clean off plate build up as well.
If I have a concern that I may forget I have the manual charger running and it may be on the battery for a week/month I flip it over to the 12v/2 amp setting to be on the safe side because the amperage output will be too low to deflect the amp meter needle and the charging voltage will be limited to around 15 volts.
If any auto/MH size battery after 24 hours at the 6 amp setting only drop the needle down to 2 amps the battery is NOT healthy and will need to be replaced when it no longer does the job expected of it. If the needle only drops down to say 3 amps the battery is junk and most likely you will hear some gassing going on.
Actually it was only after doing a lot of things to try to recover FLA batteries of the 75+ AH rating did I learn how a TOTALLY manual 2/6 amp battery charger would tell you all you need to know about the health of a lead acid battery. Hydrometers and load testers are nice for fast answers IF the battery is fully charged but will not get any more useful info than this $30 manual 6/12v charger.
Some read how you can not charge at more than 14.4 volts and think 16 charging volts will kill a full size battery in short order. We have a 200 amp manual wheeled charger that will melt down a 60 pound battery at 16 volts at say 40 amps charge rate for sure.
The key I have found is the charging rate AND the charging voltage. 16 volts at next to no amperage rate has never killed a car or trolling motor battery in my personal experience.
Personally it is the charging amperage that concerns me when it comes to lead acid batteries and not the charging voltage.
All batteries die over time. Add abuse as we all do from time to time if not full time and all batteries will die BEFORE their time. :(
