TR2/3/3A batteries today are as powerful ?

I do not think batteries today are as powerful and well-built as they were. What would the early type starter pull for amperage? Now, I am thinking I should get a new 725 cold cranking amp battery before I pull the starter. Presently, I have 2 year old 625 CCA and it might be wearing done with the new engine or the starter? Do others have more experience here? My Saabs get maybe 3 years on a battery when they used to get 5 or 6.

I agree with you to some extent. The "problem" is that lead has become somewhat expensive, while improved manufacturing techniques have made it easier to build a battery that will deliver a lot of current for a short time, while having less actual power stored (and less lead used). Compounded by the fact that modern charging systems take much better care of the battery, while the TR2-4A charging system is primitive at best. When properly adjusted, it swings between overcharging (driving at speed without headlights) to discharge (idling with headlight on). The old batteries were better able to deal with this, due to having a higher RC (reserve capacity) (the modern equivalent of amp-hours).

But, the early TR2-TR3 starter is only supposed to draw less than 300 amps while cranking, with a stall current (not turning) of around 500 amps. So 625 CCA should be plenty.

FWIW, if you have a Costco nearby, you might look into buying a battery from them. I couldn't get them to tell me what their actual policy is; but they replaced a 4 year old battery for me for free. A sharp contrast to O'Reillys, who wanted to charge me full price for a 3 year old battery that had failed (and said 72 month warranty right on the battery). Even with the "adjustment" I eventually argued them into, the replacement cost more than I had paid originally!

With Costco, the trick is to return the battery to customer service for a refund, rather than to the automotive department for a warranty replacement. CS will refund the purchase price, then you can walk around the corner and use the refund to buy a new battery (with a new warranty). Costco really bends over to make sure customers are satisfied with their products!

I presume that is why old batteries would slowly die. They would crank slowly and finally start the car now there is no warning.

We had one go bad last week. Started the car and drove to the store 30 minutes later when we came back to the car there was no attempt to start.
Is that the battery or is it the electronics in the car preventing a low battery trying to crank it over?
It was an O'Reillys battery with a 48 month warranty that was 50 months old. The guy in the store said bring the core in tomorrow and I will try to give you a break on the price.

David

DavidApp said:

Is that the battery or is it the electronics in the car preventing a low battery trying to crank it over?

Click to expand...

Very likely the electronics won't let it try to crank with the battery very low. I don't know if they are all that way, but on my 2013 GM pickup, the starter is controlled entirely by the computer. The switch is just a computer input.

I did not think to try the battery on my old MF35 to see if there was enough in it to crank the tractor. It did show 12.5 volts.

David

In the nineties and aughts I had batteries in my daily drivers that lasted 10 years or more. Lately the replacements seem to make it about three years, and, as mentioned, then die rather suddenly. Replacements have gotten expensive too .

My old car batteries never have lasted as long, as Randall noted, less sophisticated and steady charging systems, plus they tend to sit idle for long periods in the winter.

One of the problems is we all got stuck on buying the highest “cold cranking amps”. To get that, the plates are made very thin and stamped out in production to get the absolute greatest wetted surface area. This amount of area gives the most electrochemical transfer to get the most amperage in a shot. This works great for the manufacturers, as they can advertise high cranking amps using relatively lower amounts of lead (read...cheaper!).

Deep cycle batteries are closer to our older style batteries front the 1960’s and ‘70’s. They use more lead in thicker plates, but therefore have less wetted area to get the high cranking amps. But, they perform better at low and medium amperage. Read...the will sit there and grind a starter a lot longer.

So...back to the thin, cheap lead plates. As you charge and discharge batteries, lead is transferred to and from the plates. Thin plates do not tolerate this well, so a full discharge will usually permanently damage the battery. The thicker plates handle it much better, and so are more tolerant of a full (accidental) discharge.

Basically, in my book we did this to ourselves in the battery department. Too much emphasis on cold cranking amps over a more durable design. I now buy my batteries by weight. I buy the heaviest battery I can find...the assumption being there is more lead, and therefore more durability. I find I am not replacing batteries every 2 years like I was for a long time.

"Thin plates do not tolerate this well, so a full discharge will usually permanently damage the battery."

Not really what I wanted to hear, as my "new" battery sits on a charger right now after a total discharge this winter. If dead or damaged will have to see how the warrantee works I guess.

None of the lead-acid batteries like being left run flat for very long; new or old, wet or dry.

But sometimes, a "desulfating" charger can bring them back. If it just refuses to take a charge at all, might be worth buying one to try.

Or I've had some luck using a "poor man's" version, consisting of just a diode and a 40 watt incandescent light bulb. The commercial ones work better, no doubt, but I've resuscitated a few sulfated batteries with the poor man's version.

None of this will work if the battery was frozen, though. If the sides of the case are bulged out, just buy another one.

So, Randall, I've always wondered what the "desulfating" setting is actually doing. I understand the plates get coated with a lead sulphate when run flat, but what does the charger do to remove it?

Basically, it delivers very short pulses (microsecond region) of relatively high voltage to the battery (as much as 50 volts, depending on battery condition). Lead sulfate is a very poor conductor, but with a high enough voltage, you can force a tiny bit of current through it. Each little bit of current drives some of the sulfate ion back into solution (converting it slowly back to lead oxide).

I'm less clear on how the short pulses interact with the areas that aren't sulfated; but apparently they somehow keep the electrolyte from being split into hydrogen and oxygen (as would normally happen with a high charging voltage). I don't know if the very low duty cycle gives the ions time to recombine, or whether it just drives that part of the cell into the region known as "surface charge" without actually causing electrolysis. I do know from my own experiments (long ago), that it's important to limit the average current to a very low value, so the battery doesn't get hot or outgas. AGM batteries in particular (which is what I used to play with) will be ruined if they get hot or any gas escapes.

Back in the early 80s, I worked for a company that sold systems based on HP minicomputers that had battery backup for the solid state RAM. The backup was intended to allow them to survive short power outages without losing the program in RAM. (If the program was lost, it would have to be reloaded from either paper or magnetic tape, a rather tedious process. No hard drive.) Unfortunately, although the backup power supply would shut down if the battery got too low, it still monitored battery voltage and would eventually run the battery flat. If power was not restored in a timely manner, the batteries would be "ruined", meaning they wouldn't take a charge from a normal charger. So we got a fairly steady flow of battery packs back from the field, which the company just pitched and replaced with new. I used to salvage the packs from the trash and drag them home, where I would connect them to a bench power supply and run the voltage up until they would take just a tiny bit (20ma seemed to be about ideal) of charging current, then leave them that way for several days (or weeks). They didn't all come back, but I'd guess maybe 2/3 of them did, giving me some cool little batteries to play with.

Gates X cells were somewhat larger than a D cell, rated 2 volts & 5000 maH. One of the neat things (to an inveterate tinkerer like me) was that they could deliver a LOT of current for a short time, upwards of 50 amps when new. They worked really well for things like lighting rocket motors and starting fires.

Cool...thanks!