Battery replacement and opinion

[Roler]

I think I worked it out (in my nightshift) with the BTS 'hack'.
From reading up on this, the resistance at 25C temperature is around 9000-11000 Ohms. When its cold, the resistance is higher and comes down when temp increases. I noticed that my dash voltmeter (verified this in the past, its pretty accurate) reads higher on 'cold' mornings, indeed suggesting that the sensor might be working, and thus resulting in an higher alternator output via the PCM. Resistance is measured at the connector (where it plugs into the 'engine' side if things).
So, my plan is to disconnect the sensor, put it in the fridge with a thermometer and when it hits around 10C, measure the resistance. Then find myself a resistor that matches that value and fab it in place of the BTS. This way it might fool the PCM to tell it the battery is 'cold' at all times, resulting in a higher voltage output from the alternator (and thus charging the Optima Yellow Top with the recommended voltage) . Could this work?

Option B is: I found that the Supercharge Gold MF50 battery has a CCA 650 reading with RC 107, which is 110CCA more than I used to have so far. $175 with 20% discount on my next purchase at Autobarn since I joined the "Autoclub" and 36 months warranty...Then look into LED's etc....

[junglejuice]

I'd still look at the AC Delco, cheaper then the supercharge...

I found the thread I was thinking of regarding the BTS...

http://www.ausjeepoffroad.com/forum/...light=charging

This is is one part of it and summarizes the BTS mod that I performed (and still running)...

"This morning I fitted my replicated BTS which is essentially a pair of 47k resistors in parallel which results in a resistance of approx 23.5k.
This netted me a running voltage of 14.3V which is perfect, far better then the 13.7V I was originally getting and just tops the 14.2V I was getting when it was OBD1."

[Roler]

That thread says it all JJ, thanks.
Looks like Billnick at post #13 had a similar suggestion as I thought I was going to do...
Man, I once knew this, but why again in parallel the 47K resistors to get the 23.5 K eventually? And in the last post in that thread Darkside mentioned he done it in series...or is that because the 10K+10K adds up to that 20K-ish total?
Like said, once there was a time I knew all this...

[werd]

Originally Posted by Roler

Aah, the Battery Temp Sensor...but how to tweak?

I just popped the sensor out of its hole and dropped it down behind the headlight where there is much more cool air.

I'm not fixing it, I'm improving it!

[werd]

You could try super capacitors. In theory it looks good. They don't take much to charge. And you would have more space under the bonnet.
https://youtu.be/z3x_kYq3mHM

I'm not fixing it, I'm improving it!

[junglejuice]

Originally Posted by Roler

That thread says it all JJ, thanks.
Looks like Billnick at post #13 had a similar suggestion as I thought I was going to do...
Man, I once knew this, but why again in parallel the 47K resistors to get the 23.5 K eventually? And in the last post in that thread Darkside mentioned he done it in series...or is that because the 10K+10K adds up to that 20K-ish total?
Like said, once there was a time I knew all this...

Electrically it makes next to no difference re series or parallel, I went with parallel so I could twist the tails of the two resistors together on both ends, this along with a couple of layers of heat shrink gives me what I feel a more "rugged" solution, as they're twisted together they help support each other to (hopefully) prevent breakage, this along with the double layer of heat shrink and the addition of some 2.5mm2 building wire inside should relieve some or most of the stressof bouncing around in the engine bay.
Overkill?
Maybe, but I want reliability...

[Roler]

I can see that; its just that I would reckon a 47 K resistor is exactly that, isnt it? How come it ends up being 23.5F resistance?

Series Resistance Rtotal= R1 + R2 etc (thats the easy one)

Parallel Resistance : "1/Rtotal= 1/R1+ 1/R2 etc

I'm just trying to understand what I'm doing, to prevent future questions. That, and just curious...knowing there are electric-know how people here


EDIT: I think I just answered my own question.....nightshift brain....