Battery Longevity

[Cougsfan]

My question is -- can a fully charged battery - in fact - be a dead battery?

I like to use the analogy of an electrical system to a hydraulic system where volts can be comparable to pressure (psi) and amps are comparable to flow (gpm). Imagine a 100 foot high dam holding back a large lake with a 3/4 inch valve at the bottom of the dam to let water out. If you were to put a pressure gauge on that valve it would read 43 psi (1 foot of water head creates .43 psi of pressure). Now take a 100 ft long garden hose, put a valve and pressure gauge on the lower end, fill it full of water and somehow hold the other end 100 ft up in the air. That pressure gauge will also read 43 psi. Open each valve for a minute and close it again and read the each of the pressures. The dam will have flowed a lot more water and still read 43 psi while the hose had emptied out maybe a gallon or two then stopped flowing and now reads 0 psi. Using this analogy it is easy to visualize how a bad battery with diminished storage capacity can show a full charge and not have the capability of flowing enough amps to run your starter.

 

[Gregster613]

Grumpycat, I did not use voltmeter whilst actually trying to start, but did test right after and battery volts dropped dramatically. 13.6 to about 9.5V. This was my first clue that battery was bad! At first I thought it just ate another switch, but pondered on it for a day or so and gave further tests to show that the switch was still working. Then I used my HF load tester - of which I still don't understand how it is supposed to function, - but it showed in the fail zone on the "fully" charged battery that wouldn't run the starter on the genny. Thus leading me to believe a failed battery was the culprit. This is what confounded me: a fully charged battery not juicing the starter?? I thought it was probably a toasted battery but just wanted confirmation on my unqualified tests. This small battery doesn't even list on it the CCA's it's supposed to produce? My tester goes down to 300, but.... Thanks for the quantified reply. Greg

 

[user.69169]

It's the nature of lead acid battery to self discharge over time. Dat yer first problem.
Second problem is how battery connects individual cells together wid nothing but friction rather than cells being soldered like in old days. Over time dem connections grow crud between surfaces, dat limit current flow.
Voltages you seein indicate 2 cells in dat battery no longer employed. Best to just change out battery. You don't good chance you blow out regulator on machine for extra expense.

Battery be whole lot happier if workin den just sittin around easy enough to do with some tail light bulbs and couple boards you can buy on ebay for few bucks. One board loads bulbs onto battery till voltage drops to preset level and den disconnects load. Second board watches battery voltage and turns charger on at preset voltage and back off at full voltage.

 

[goeduck]

I bought a (I think $35 at the time) Schumacher actual load tester to check real Amps. Cannot beat simple. Runs the current through a heating element.

https://www.batterychargers.com/sites/default/files/manuals/0099001450-R1.pdf

 

[Gregster613]

goeduck, My tester looks exactly like the one you have. I bought it at a pawn shop and did not get the instruction sheet. Now I do, Thanks for posting that. It works as I thought it should, but prior to reading the instructions I was just guessing. Now I understand this simple tool much better.

(removed), Yes my battery is just dead, even though it shows on multimeter and my big charger that it's fully charged. Put a load to it and nada, zip. I ordered a replacement today. Will get it in tomorrow. I just hope with these new high winds we're getting today that power won't be shut off before tomorrow. Doesn't bother me so much, but it irks the wife!

 

[user.69169]

Easy way to unirk wife, tell her you read up on old Civil Defense shelter generator, bicycle frame wid generator attached. Sit on bike, peddle and make electrons. Tell her she can peddle while you do other jobs.

5 bucks says wife forget all about electric.

 

[fried1765]

Easy way to unirk wife, tell her you read up on old Civil Defense shelter generator, bicycle frame wid generator attached. Sit on bike, peddle and make electrons. Tell her she can peddle while you do other jobs.

5 bucks says wife forget all about electric.

Obvious solution!:laughing:

 

[Gregster613]

That's a "very" good one (removed)!! I LOL reading it, but 5 lousy bucks won't even come close to covering any divorce payments; so thanks again, but I'll just pass on that thought.

 

[Industrial Toys]

I bought a Princess Auto (HF like) Carbon Pile tester. Went snap, crackle and pop the first time I used it. Went back to an element style tester.

 

[user.69169]

Carbon real funny joke by Mother nature, sort of like Sperm Whale oil. Carbon shrinks when heated unlike most other materials. Electrical resistance changes as is compressed too.
Carbon dust will make a normal woman into full blown mass murderer when she gotta clean it up too.