Calcium and Silver Alloy Sealed No- Maintenance Batteries

[Doctor W]

Since fitting a top of the range Aussie-made (rare these days!!!) Calcium and Silver alloy sealed no-maintenance battery I've discovered that the desirable range of charging voltage (14.4V - 15.6V) is not happening on my ZJ. The PCM "thinks" it knows best and gives an absolute top charging voltage of 13.8V which is fine and dandy for regular batteries, but will never give a full deep 100% charge. ......... Any one else find this problem?.......What's the solution if you want to keep up with latest (and best?) battery tech AND have a car that'll still start after a few days of opening and shutting doors (8 lights on for 30 secs after door closing) or listening to sound system for an hour?Which of course it should be much more than capable of doing for even longer times with this new battery!.......THIS IS AN INTERESTING TECH Q, cos all new batteries being made are going to be of the calcium type, at least - so it will affect a lot of Jeepers eventually, sooner rather than later.

[Deezelweazel]

There is a voltage sensing in the PCM.
You can bump it with a simple diode up to 0.7V higher than usual, depending on the diode (0.3V, 0.5V, 0.7V).
This is also done with the use of diode insulators- same principle to compensate voltage drop and to ensure proper charging.

I switched my interior dome lights to LED's.
Power consumption of the filaments bulbs was way too high.
7 bulbs with a wattage of 5 to 10 watts draw a lot of current. What a waste!

No maintenance just states the battery are sealed and need no refill under normal conditions. They are sensitive to overcharge and will loose fluid when charged with 15.6V- definetly not a good idea!
Most chargers will operate in the voltage range of 14.4V up to 14.7V. But the second voltage is recommended for AGM batteries or cold outside conditions.

If your charging voltage is that low, you maybe should check your brushes. Replacing them with fresh ones will give you a bit voltage back due to better surface contact.

Charging the battery isn't a problem. The battery demands the current. Only voltage is regulated by the PCM.

[turbomart]

Originally Posted by Deezelweazel

There is a voltage sensing in the PCM.
You can bump it with a simple diode up to 0.7V higher than usual, depending on the diode (0.3V, 0.5V, 0.7V).
This is also done with the use of diode insulators- same principle to compensate voltage drop and to ensure proper charging.

I switched my interior dome lights to LED's.
Power consumption of the filaments bulbs was way too high.
7 bulbs with a wattage of 5 to 10 watts draw a lot of current. What a waste!

No maintenance just states the battery are sealed and need no refill under normal conditions. They are sensitive to overcharge and will loose fluid when charged with 15.6V- definetly not a good idea!
Most chargers will operate in the voltage range of 14.4V up to 14.7V. But the second voltage is recommended for AGM batteries or cold outside conditions.

If your charging voltage is that low, you maybe should check your brushes. Replacing them with fresh ones will give you a bit voltage back due to better surface contact.

Charging the battery isn't a problem. The battery demands the current. Only voltage is regulated by the PCM.

Where would you install the diode, on the alt output wire or do you need to find the batt sense wire to the pcm?

[Deezelweazel]

You have to install it into the sensing wire.
It would burn instantly with the high current on the output.