You can pop off the cell caps and check the voltages between cells. They should all be the same at about 2.05-2.1V. One terminal is at the same potential as the adjacent cell, the other will have that same 2.1V between it and the adjacent cell, so you should get 6 readings. I was fighting a battery in my wife’s vehicle that, by Friday of the week, after charging it on the weekend, wouldn’t start her vehicle. The auto shops said it was fine. Finally, after trying to chase parasitic drain, I took off the caps, and started measuring individual cells. I found a short between two of them. This was on an 18-month-old battery, when I normally get 5-6 years on them here.
I keep Battery Tenders, and NOCO's on every small battery, and regular ones that sit for more than a few days at the time here. I forget how many years I've been doing that, but I've not had to replace a single battery since then. There are four full sized tractor batteries that might be 10 years old.
Our Farm Use car battery dies every few months. That car doesn't run long enough at the time to charge the battery, but we don't want to bother to plug, and unplug a charger every time we use it. Charged with a 10 amp NOCO, it's good for another several months. It's been doing that for some years now, and wasn't new for several years before that.
They do, but how much of that actually shows up as charge current at the battery? It's connected in parallel with the rest of the electrical system...I've never been able to get my head wrapped around the effective "resistance" of a battery, which makes any normal Ohm's Law calculation a bit sketchy.
A related question I've never gotten a plausible answer to is, how much driving does it take to fully recharge from a typical cold start? Due to the local geography (e.g. less than a mile to Home Depot ), I'm kind of the poster boy for short-trip-driving, so it's actually something that might be a concern.
Yoga class makes me feel like a total stud, mostly because I'm about as flexible as a 2x4.
"Design"? Possibly. "Intelligent"? Sure doesn't look like it from this angle.
We used to be hunter gatherers. Now we're shopper borrowers.
The three most important words in the English language: "Front Towards Enemy".
The world makes a lot more sense when you remember that Butthead was the smart one.
You can never be too rich, too thin, or have too much ammo.
Yoga class makes me feel like a total stud, mostly because I'm about as flexible as a 2x4.
"Design"? Possibly. "Intelligent"? Sure doesn't look like it from this angle.
We used to be hunter gatherers. Now we're shopper borrowers.
The three most important words in the English language: "Front Towards Enemy".
The world makes a lot more sense when you remember that Butthead was the smart one.
You can never be too rich, too thin, or have too much ammo.
Yeah, my 2007 minivan fires up instantly, but my wifes 4Runner cranks pretty long compared to most it seems.
I was on a 4Runner forum trying to find out about originl battery life last year and people had great longevity with original equiptment battery. It is made by Panasonic. I thought I would replace hers with a Panaonic but found out they don't sell them in the U.S.
Yoga class makes me feel like a total stud, mostly because I'm about as flexible as a 2x4.
"Design"? Possibly. "Intelligent"? Sure doesn't look like it from this angle.
We used to be hunter gatherers. Now we're shopper borrowers.
The three most important words in the English language: "Front Towards Enemy".
The world makes a lot more sense when you remember that Butthead was the smart one.
You can never be too rich, too thin, or have too much ammo.
Funny thing about the AA batteries. For a Middle School science project, a student in the school I taught at compared AA battery life of several name brand batteries and off brand (store brand). In his experiment, CVS batteries out lasted them all in a flashlight test. I never bought the name brand again although I realize it was a school experiment, I figured at best they were of similar longevity and not worth the $ premium for the name.
Last edited by Ron Citerone; 01-11-2022 at 9:52 AM.
Battery resistance measurement is essentially the change in output voltage during an increase in discharge current.
For large cells internal resistance will be between maybe 80 and 400 micro-ohms, depending upon battery condition and capacity.
That’s why batteries are so dangerous, very low internal resistance yields very high short circuit currents. Many cells have short circuit currents between a few thousand and 30 thousand amperes…..Rod.
Last edited by Rod Sheridan; 01-12-2022 at 4:33 PM.