Batteries

[ziegler]

One of my batteries is 12.7 volts and the other is 11.5 volts. The engine cranks but won't start. Will the battery under 12 volts prevent it from starting? Thank you.

[whitesik]

It is possible. If those voltages are after charging, then the 11.5v did not take a full charge and is probably bad. Cranking voltage would be even lower.

[rmel]

Here comes 1,000 questions

What type batteries do you have: Lead Acid or AGM.
AGM @ 11.5V is a 10% charge.
Lead Acid is essentially dead below 11.5V

Which battery is at 11.5V, bottom or top?
Try charging your batteries individually with a 12V charger.
That weak battery may NOT take a charge and bad cell(s) -- but worth a try.

Are you running with the stock ignition or aftermarket?
If aftermarket, Pertronics or PinzSSI (what version)

[ziegler]

Lead acid batteries with PinzSSI. I will try to trickle charge the battery closest to the tool box that's at 11.5.

[ziegler]

I'm running the optima 3478 batteries. IF the back battery is dead, can I run a new AGM optima with the other lead acid battery? Or is this a no no.

[rmel]

Can't mix and match Lead Acid with AGM, won't charge balance correctly.
For that matter you really need to have both batteries identical and the
same age. Even still charging won't be perfect.

I asked about that ignition your running as you implied the engine was
cranking -- with the stock Ign you probably would have started. So I got
suspicious you had some form of SSI. The early PinzSSI's (1.0) were vulnerable
to lowish battery voltage.

[ziegler]

Thank you very much for your input. Time to buy 2 batteries and listen to the wife complain for a couple of days. It's worth it, I love my Pinz! This will be the third time in 21 years I've replaced the batteries.

[whitesik]

On a little side note and out of curiosity, if one was on the road and had this problem, could an external 12v source be applied to the PinzSSi just to get the vehicle started. The PinzSSI runs from a 24v to 12v DC to DC converter. Would bypassing the converter work? If even directly from the one good battery? Perhaps I am crazy here.

[whitesik]

Ah ,, forget it. There is that starter thing.

[rmel]

It's a good question Keith. And all depends upon the PinzSSI version.

The 1.X generation was the most vulnerable to the quality of the
24V source. The fist incarnation took power for the Coil pack and
the Module from the bottom battery, so if that was low and while
cranking even lower you could be in a situation where there was
insufficient voltage for the module to work and thus no trigger
to the coil pack. There was a tweak on the power delivery scheme
for the 1.x generation but that too could be exposed to low 24V.

The 2.0 and later versions added a Eaton DCDC converter which
pretty much eliminated the issue -- as long as the 24V didn't go to
too much below 18V.

So...if one is stuck in a situation where the battery is near dead,
but you can crank but no spark....it's jumper cable time. Or
if your lucky on a steep grade to pop the clutch.

[whitesik]

Thanks Ron as always. I just wondered. I usually have a couple 12+v batteries with me for radios that may power the pinzssi but not be good for cranking.

[Stumbler]

This entire discussion seems a little derailed.

A battery can throw 11.5 volts, or even 12.x, on a standard voltmeter and not be able to crank an engine. It's the amperage that counts most. If the battery is bad, and not showing obvious signs, the only real way to test it is under load. The starter pulls an immense amount of energy and that's hard to duplicate on each battery in a Pinz since they are run in series. Since you can't try it with one and then swap them out and test the other, the simplest and easiest way is just to take the batteries out, clean them up, put them on the charger until you think they are fully charged, and take them by your local Autozone. They will put them on their meter for free. (And it's a different meter than a simple voltmeter, is has a resistance load of 50 to 100 amps) They can tell you within reason if the batteries are fine, need help, or dead.

On a side note: The way Styer run the batteries in series and charged them is inherently wrong. It was the technology of the time. It always results in one battery charging or discharging a tiny bit faster than the other. Some people use an isolator to help fix this. Personally, I just put the battery charger on them about every 6 months and let the charger desulfinate and top off the charge.

[rmel]

Ya, series batteries is not ideal.

I do swap the positions on occasion and regularly charge then
individually with a 12V charger.

You can test these yourself, with a load tester, they are fairly inexpensive.
https://www.amazon.com/dp/B07Z67MMGC?re ... n_title_24