Optima battery temperature sensor modification?

[AZMotorgod]

I have looked and looked, but I can not find how to perform this modification.

I have seen lots of information for and against the Optima but I am going to give one a try. (I really don't want to have to scrub corrosion and then re-paint my battery tray again.)

When I placed the battery as close to the sensor as I could it still seemed to have a slight gap, which I am guessing is not good. Is there a "real" modification, as I don't want to duct tape it to the battery, that just seems cheesy.

 

[AZTVR]

Seems like a wrap of duct tape would be fine. Use brown Gorilla tape or black "racers tape" if you want something that doesn't look quite as redneck. No one but you is going to see it anyway.

By the way, I found out that if you allow the Optima to discharge below 10.5V, many semi-modern chargers will not charge it. Because of its design, it will draw more current than a wet cell battery, and the charger may go into protect mode because that is an indication of a wet cell battery shorted cell. The Optima is still likely good in that state, and can still be charged back up.

 

[bluesrt]

i know for a fact that a battery tender will charge a stone dead optima fine- unreal how so many people have a problem with this battery= as for the temp sensor, just leave it be how it is

 

[Jack B]

Seems like a wrap of duct tape would be fine. Use brown Gorilla tape or black "racers tape" if you want something that doesn't look quite as redneck. No one but you is going to see it anyway.

By the way, I found out that if you allow the Optima to discharge below 10.5V, many semi-modern chargers will not charge it. Because of its design, it will draw more current than a wet cell battery, and the charger may go into protect mode because that is an indication of a wet cell battery shorted cell. The Optima is still likely good in that state, and can still be charged back up.

I had the same problem with a 2A maintenance charger, but, with a 12A charger it worked fine.

 

[AZMotorgod]

bluesrt-
Meaning, just leave it with the small gap and it will be fine?

Jack B-
What is the difference between the two and how can you tell if a charger is one or the other?

 

[bluesrt]

bluesrt-
Meaning, just leave it with the small gap and it will be fine?

Jack B-
What is the difference between the two and how can you tell if a charger is one or the other?

yes just leave it be

 

[Steve-Indy]

In the great scheme of things, I personally have NO ABILITY to rate (or quantify) the importance of the battery temperature sensor and its effect (of lack of effect) on a Viper's charging algorhithm. It's there, the service manuals make references to it...but just how important is it? Keep in mind that we have big alternator outputs. onehas to also wonder about battery life if charged sub-optimally. I plan to continue using batteries that utilize this built-in sensor.

Decide for yourself...if you can

http://batteryuniversity.com/learn/article/battery_definitionshttp://batteryuniversity.com/learn/article/battery_definitionshttp://batteryuniversity.com/learn/article/battery_definitions

http://www.tekrispower.com/pdfs/xantrex/Batteries%20-%20Temperature%20Compensated%20Charging.pdf

http://www.nrel.gov/vehiclesandfuels/energystorage/pdfs/evs_17paper.pdf

http://www.localenergy.org/pdfs/Document Library/Fundamentals of batteries and charge control.pdf

http://batterytender.com/resources/battery-basics.htm

 

[Jack B]

bluesrt-
Meaning, just leave it with the small gap and it will be fine?

Jack B-
What is the difference between the two and how can you tell if a charger is one or the other?

The charger nameplate will tell you. The 12 amp charger is physically much larger. I have run the red-tops since 2002 without issue due to the battery sensor. I have always used the 2 amp "Battery Tender" and it has worked fine. I left the overhead light on for a few days and the 2 amp charger would not bring it back.

A huge caveat, I use the permanent ring connector cable that came with the Battery Tender, this allows a quick/safe attachment of the charger. One end has ring terminals and the other end has a male and female connector. That connector has a cap on it for a good reason. They flop the leads on the connector/cable and the exposed male connector is the positive 12 volt lead, versus the recess female which is the negative. My point is, when the charger is not connected if you do not use the insulated cap the projected terminal is the hot lead.

 

[bluesrt]

i have had a red top stone dead more than once and the battery tender brought it right back strong- it takes time

 

[AZMotorgod]

Well, I am taking a chance on the Optima Red Top with side terminals only (fit was excellent).

I put it in and buttoned it up. The car's battery temp sensor is not quite touching (seems to have about a 1/2" gap or so) due to the shape of the "six pack" style of the Optima but my tech said not to worry.

However, I had an issue. I had the battery sitting around for about a week prior to installation. For thefirst several days after purchase I did have a Napa smart charger on the battery to keep it topped off, but then for about tree days or so prior to installation I had the charger off (thinking that I might take it back and get a regular style).

Anyway, the issue came when I went to start the car for the first time. I had enough juice to run the accessories and door chime but the car would not start. I would attempt to turn over but would not fire. I ended up having to jump it.

I don't think I had a battery issue but an issue with the "Wide Open Throttle" Voltage. When I first turned the key I forgot about mashing the gas five times and then turning off the car, waiting a while and then trying to start. I turned the car on, did not do anything, and then turned the ignition back off. Remembering about the WOT voltage thing, I went and looked at the procedure and then did it. Was I too late? Did the voltage range get incorrectly set on the first ignition on cycle, thus causing some kind of non-start issue?

Once it was jump started I had to keep my foot on the gas partially for several minutes until it would idle on its own.

Just food for thought for someone else who might be in the same boat after a battery (of any kind) change.

 

[kickinasp]

The battery sensor is used to determine the voltage to charge the battery at. The charging voltage range is 14.75 down to 13.5. 14.75 occurs at approximately 20 degrees F. So only in cold conditions could you possibly under charge your battery if the sensor were to warm up faster than the actual battery (which is like a big brick and takes time to warm up). The main concern in any battery charging is over charging the battery. Overcharging will shorten the batteries life and on wet cell batteries could leak acid (boil over). So having the sensor touching the battery case is optium for accurate charging. If the battery temp rises due to high voltage charging and the sensor is not touching its possible that the amount of charging current could be higher than necessary and eventually lead to battery acid leakage. Lets be honest, most of us dont drive the vehicle enough to keep the battery at a full state of charge. Therefore the system has a tendency to chrage at a higher rate and thats why batteries dont last as long in a Viper as other vehicles. Since the factory battery is a wet acid style, the battery charging curve is programed for this application which might not be optimum for other battery constructions. So either way..having the sensor touch the battery case is the best approach.

 

[proedge]

I noticed that my temp sensor is loose in the tray and is not really touching the battery. should it be contacting the battery at all times? My car has been acting strang lately, when starting it seems that all electrical systems shut down in order to crank the engine... barely. I was going to replcae the battery to see if that made a difference, then noticed this loose sensor thing in the tray. should I replace the sensor or just try to make it more secure in the tray?