The other day I came out to start my '23, turned the key to battery, coils buzzing, depressed the starter button, and nothing. Battery terminal voltage was right around 4.5V, so I put a charger on it a few hours. Didn't have a chance to run it then, so I came out today hoping to do so. Same thing happened as before, this time with noticeably weak coil buzz. Terminal voltage is at 4.4V.
What is the voltage on a fully charged nominal 6 Volt battery? And also is there any worry with phantom loads on a completely stock T? Up until about 6 months ago, I disconnected the battery after each use, but I have gotten out of the habit. Just wondering if something is drawing it down, or if its just time to replace the battery.
Thanks,
Dan B
6.3 volts.
Dan,
Probably should disconnect the battery and see if it will take a charge. That would eliminate any drain in the car and should tell you if the battery is any good. Depending on what size your charger is it may take a day or more to charge if at all.
If it set for very long at 4.5v, that is probably the worst thing you can do to a battery.
How old is the battery? Depending on how the battery has been used/treated the age may give you a clue if you need a new battery. Some say to replace a battery every three year but at the same time I have 14 year old batteries in my p[pickup and they are showing there age but still serviceable.
Jim
I agree totally with Jim Thode's comments. I would only add that if you do get a new battery, it would be a good idea to make sure that you don't indeed have something pulling the battery down but if you do it is probably a rather small current and might be hard to find since you do have some residual voltage there. That does not mean that you should ignore the small drain and not look for it since I too have 11 year plus life out of my T battery because there is nothing pulling it down when I am not using the T and my system always puts the T away with a fully topped off battery. I would strongly suggest you not install a battery disconnect switch as some sort of "fix". Those cause more trouble than any single device you can put on a T. Folks on the forum can help you find any "phantom" drain and with a little persistence you can prevail.
Hi Dan, Try charging with a trickle charger for 24-48 hours. If the plates are sulfated the slow charger may break it down. When you get a new battery you need to charge it also for 12-24 hours with a trickle charger. A charged battery will live longer than one bought and installed as a new battery has not been charged just acid added.
Dan
If you go for a new 6 volt battery take your voltmeter along and buy one that measures at least 6.3 volts or better.
Yes, you may get some odd looks, but you will also get a battery that has not been sitting on the shelf for an extended period of time.
Place the new battery on the trickle charger for 12 hours, let it sit for an additional 12 hours and recheck to see it reads 6.35 volts.
Make yourself a flea power charger that places about 100Ma across the battery when you leave it sit for long periods of time unused, like over the Winter.
As Jim and John point out, lead acid batteries will last a long time if properly cared for.
Ron the Coilman
Thanks for the feedback. The battery is about 10 years old and has never had a tender on it. I have it on a 6V/6A charger now.
Can someone educate me about battery failure? My plan is to charge it tonight, disconnect it, check voltage before going to bed, and check it again tomorrow night. A failed battery does not hold a charge, right? Is it also possible that a bad battery will also not take a full charge? What's more likely and are they related?
Finally, can anyone recommend a good charger and battery tender? I have a straight up charger, with no float voltage or maintenance mode. It also doesn't shut off once it reaches the correct voltage, so I'm always running out to check it. I don't know, call me crazy, but I feel odd about having a tender plugged in all the time unattended. Irrational? Probably.
Dan I highly reccomend going to www.batterystuff.com and reading their tutorials. these guys are battery nuts, look into their smart chargers.
charging a battery isnt always a good thing. over charging is just as bad and draining one. maintaining one is important.
Dan, consider yourself lucky you got 10 years out of it.
Even if it eventually does build a charge I bet it won't hold one.
Dan,
Batteries fail mostly from neglect and abuse. Over charging, letting them sit in a discharged state, and letting the water (acid) levels fall below the plates are the common reasons.
When discharged, the lead combines with the sulfur in the sulfuric acid to form lead sulfate on the plates. When you charge the battery the lead sulfate changes back to lead and sulfuric acid. If left in an uncharged state, the lead sulfate can crystalize. The lead sulfate crystals cannot be changed back into lead and sulfuric acid and the battery is toast, or at least has diminished capacity. A controlled overcharging can knock off the lead sulfate but then there are less of the plates left.
Over charging can boil out the water and cause the plates to sluff off some material that accumulates in the bottom of the battery. If enough accumulates, the material can short out the plates.
Every discharge/charge cycle diminishes the capacity of the battery. Batteries age due to these cycles. The depth of discharge also determines the life of a battery. Starting batteries are not meant to be discharged more than 10% of their capacity. Deep discharge batteries should only be discharged to 50% of their capacity.
Letting the water fall below the plates will cause the plates to dry out and crack, and possibly sluff off some material. In my experience, the plates usually don't dry out if the water level is just a little bit low and the battery can be saved by adding more distilled water. Hard water is bad for batteries because it adds minerals and metallic ions that interfere with the battery's performance.
Neil