"Hey Don, where ya been? Grin"
I've been in here every day. But sometimes I have nothing to say.
"This is an interesting theory... any explanation for why the battery's life is so dramatically shortened?"
There are known reasons why a lead-acid battery's life is shortened by deep discharges. But why it's exactly six months after is somewhat of a mystery to me. The same thing happens if such a battery is under water for a while. For an example, an uncovered boat where the drain plug wasn't removed and then a lot of rain. In both of above cases, it increases the internal corrosion and I assume it takes six months for enough internal corrosion to damage the plates inside the battery. The corrosion can short out the same plates in the battery, when enough of it gets between any two plates. It's best to keep lead acid batteries dry on the outside and well charged.
"Deep Cycle" batteries that are used in larger boats and RVs that are NOT used to start engines (there's a separate battery for starting) are larger and have the plates spaced out more. These are much more forgiving, mainly because it's harder for an equal amount of garbage to short out the plates of the battery. These batteries are more expensive, larger & heavier but not good for starting engines. The amp hours of batteries is NOT consistent at different discharge rates. IOW, with a lead acid battery, a 100 AH might work well for one 100 amps for an hour, but not 100 hours at one amp or vice versa. The Deep Cycle batteries are made to run lighter loads for much longer times. And engine starting battery is the opposite.
Because of this, the battery manufacturer will always rate the AH rating at it's best point. However, there is a standard called "reserve capacity" that will tell you the AH rating for what the battery was designed for. These ratings are more common with deep cycle batteries. Engine starting batteries usually only rate the CCA which tells us how much current can be drawn from the battery at a certain low temperature. This is usually all we need to know for a car's engine starting battery.
"As an aside: Why do you think small motorcycle batteries are more expensive than car batteries? Economies of scale? "
IMO, for the same reason all motorcycle parts are more expensive. Not as many identical parts made when compared to the same part for a car.
-Don-
Thanks for the detailed explanation!
On bike batteries: I suspect a deliberate rip-off; after all, batteries for riding mowers (about the same size, etc.) are not nearly as expensive yet surely the same issues apply. How many of "Brand x" riding mowers are in circulation, etc. Yet the battery for the mower costs $40 vs. $100 for the small motorcycle battery....
"How many of "Brand x" riding mowers are in circulation, etc. Yet the battery for the mower costs $40 vs. $100 for the small motorcycle battery...."
My lawn mower doesn't have an electric starter. What are the specs on a lawn mower battery (voltage and AH, etc)?
-Don-
This is a riding lawn mower with a twin-cylinder Kohler engine that has twice the hp of my 250 cc dual sport - so I would guess the carnking amps, etc. would have to be at least as much for the mower as the bike. I will go out to the shed and write down the specs and post them here....Originally Posted by DonTom
"I will go out to the shed and write down the specs and post them here...."
I am still very patiently waiting . . . .
In other news, my clutch sure went out fast in my 1996 Saturn SL2. In just a few days of driving, it went from barely noticing some slipping to being almost undrivable when going up hill. Yesterday, I made it to the nearest place (Wheel Works) where I could get it repaired. It should be done on Friday.
I also let them talk me into buying all new tires. The total bill will be about $1,850.00, which is almost half the price I paid for the car a couple of years ago. It has 88,000 miles on it.
I have never even tried to change a clutch. Not in anything, not even in a motorcycle. I have talked to a few people who changed them in cars and pickups and they all tell me the same thing. They were successful, but they will never do it again.
Who has repaired or replaced a clutch here as a home mechanic? Would you do such a job again?
-Don- (Reno)
Don asked;
Who has repaired or replaced a clutch here as a home mechanic? Would you do such a job again?
Back in the good old days, when I was young and healthy, I got tired of maintaining other guys cars for nowt. That was how I started my (profitable) sideline car servicing and tuning business. I'd like a pound for every clutch I changed, whilst the customer waited, in those days. Mind you the cars were simpler to work on - as an example my bro' and I, working together, changed the clutch and the front and rear gearbox bearings on a Ford Escort and the clutch on a Ford Capri in under two hours. Graham, my brother, who was a Ford trained mechanic, had developed a system which enabled him to change the gearbox bearings without removing the gear cluster. He actually changed both bearings in less time than it took me to get the box out of the Capri.
I've changed many clutches on BMC Minis, 1100s, and 1800s. With a couple of special spanners a Mini clutch could be changed in about an hour with the engine in situ.
Modern engines - don't know as I've never tried. I'm older, wiser and lazier now and pay other people to get their hands dirty on my behalf.
Ken.
Die dulci fruimini!
Ken.
Wolds Bikers, Lincolnshire, England.
I did a clutch on my '66 Galaxie, a few years later, twice, on my '65 Corvair, and quite a few years later on my '85 Camaro. I've also replaced a crank seal on a Chevy van, and r&r'd the automatic transmission to do it.
The hardest one was the Ford, because that cast iron top-loader was damn heavy.
The Corvair was easy because you could remove the jugs and rods and then pick up the crankcase with your hands. The first time, it was harder because I followed the shop manual directions and removed the entire engine/transaxle from the car before separating them. Which is the basic procedure for clutch jobs in FWD cars; I don't think I'd attempt one.
I just had the slave cylinder replaced on my '01 Camaro. The slave cylinder is toroidal, and wrapped around the transmission input shaft, so the labor is about the same as for doing the clutch. I had the local Chevy dealer do it, mostly because I'm working 850 miles from my driveway and my big toolbox. $1400 and change, more than half labor at $1.50/minute.
"Which is the basic procedure for clutch jobs in FWD cars; I don't think I'd attempt one."
My Saturn is a FWD. Does that mean they will have to take the entire engine/transaxle out? No wonder my last couple of clutch jobs cost a bit more than I expected. Both were FWD.
-Don- (Reno, NV)
"I just had the slave cylinder replaced on my '01 Camaro. The slave cylinder is toroidal, and wrapped around the transmission input shaft, so the labor is about the same as for doing the clutch. I had the local Chevy dealer do it, mostly because I'm working 850 miles from my driveway and my big toolbox. $1400 and change, more than half labor at $1.50/minute."
Geez.
See? This is why I prefer old cars. They don't even have a slave cylinder for the clutch! (And you can replace the entire transmission for around $1,400.)
No wonder so many people are in debt today - or broke!
"They don't even have a slave cylinder for the clutch! "
If a car has a slave master cylinder for the clutch, doesn't that mean it also has a slave cylinder too? I changed a clutch master cylinder in Tommy's oldest brother's Datsun. I think it was early 1980's. Is that considered old?
-Don- (Reno)
When I say "old" I mean pre 1980s... cars of that era had manly clutches. No pansy-assist!
Ever drive an M21/M22 4-speed muscle car?
Yeah. My Ford had a mechanical clutch linkage.
When it was quite young, there was some problem with it, which Ford repaired under warranty. I think it involved the dealer re-welding one of the arms on the cross shaft, and I think he warped it badly. After that, the over-center spring didn't work right.
So I was poking around in the linkage, and managed to cause the overcenter spring to pop out and fly into an adjacent field. It must have gone fifty yards; I was lucky it didn't hit me. I didn't even go look for it.
Thereafter, you had to push on that clutch pedal like you really, really meant it.
The feel was marvelous, but it was very tiring in traffic.
Like doing leg presses at the gym!
In those days, it took a man to drive a powerful car. These days, a 105-lb. girl can easily drive a 505 hp Corvette....
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