Battery Isolator ?

[Slo-Sho]

I have a Diode type battery isolator (Sure Power ind. 160a) with one input and two outputs. From the bits and pieces I've read this type of isolator drops about .6 to 1v through the diodes due to it's design.

I have a 90 Renix which originally had the Delco CS-130 105a unit w/ internal voltage regulator. It is now gone in favor of the 136a Nippondenso unit with an external voltage regulator.

My question, Is it a good idea to connect the "sense" terminal of the regulator to one of the batteries so the voltage loss is made up for? Will this alternator be alright long term charging at 15V+ all the time?

 

[5-90]

I have a Diode type battery isolator (Sure Power ind. 160a) with one input and two outputs. From the bits and pieces I've read this type of isolator drops about .6 to 1v through the diodes due to it's design.

I have a 90 Renix which originally had the Delco CS-130 105a unit w/ internal voltage regulator. It is now gone in favor of the 136a Nippondenso unit with an external voltage regulator.

My question, Is it a good idea to connect the "sense" terminal of the regulator to one of the batteries so the voltage loss is made up for? Will this alternator be alright long term charging at 15V+ all the time?

15+ volts constantly may be a bit much. What voltage, specifically, are you getting at the alternator output and at the batteries? It may not be as large a problem as you think (although this points up another reason why I don't care for solid-state isolators...)

 

[Slo-Sho]

I figure atleast 13.5v to both batteries should be sufficient to keep them charged, which means of course the alternator will be working at a higher than nominal voltage.

I couldn't help myself when I found an ambulance in the salvage yard. When I opened the doors I was amazed at all the alum diamond plating inside. Behind a panel which was hidden, there lie before me the solid state isolator, whelen strobe power packs, 3 solid state wig wag flashers, and a 200a shunt for the amp gauge in the dash. The nice feller at the counter charged me $5 for each box and the amp gauge and shunt were free.

 

[5-90]

I figure atleast 13.5v to both batteries should be sufficient to keep them charged, which means of course the alternator will be working at a higher than nominal voltage.

I couldn't help myself when I found an ambulance in the salvage yard. When I opened the doors I was amazed at all the alum diamond plating inside. Behind a panel which was hidden, there lie before me the solid state isolator, whelen strobe power packs, 3 solid state wig wag flashers, and a 200a shunt for the amp gauge in the dash. The nice feller at the counter charged me $5 for each box and the amp gauge and shunt were free.

You didn't happen to grab the wig-wags, did you?

Assuming you're losing .6VDC across the isolator, getting 13.5VDC at the batteries would be ~14.1VDC at the alternator, which should be fine (my 195A Delco runs ~14.4VDC constantly, and has been doing so for years.)

I'd check to make sure of the losses - but if you're getting ~13.5VDC at the batteries (nominal) and >14.5VDC at the alternator (what I consider max - although I've heard of people pushing 15VDC without too much trouble...) you should be fine.

 

[Slo-Sho]

Thanks for the reply, and yes, I grabbed everything I could get my hands on. The guy at the counter asked me what the isolator was (he had no clue) and I told him it was a johnson controller module. $5 later, THANK YOU.

 

[MudDawg]

Much over 15 volts and you will start boiling the magic smoke out of the battery (it's a good idea to regularly check the electrolyte level in the battery on a regular basis) because the electrolysis can vaporize the water from the battery faster than the caps can condense it and return it to the battery. At around 16 volts sensitive things start to roast. At 17+ volts it really gets cooking.

In a related topic...I like the fact that Jeeps have a volt meter...it tells you all you need to know....an Ammeter can give you a false sense of security because it is very possible (and common) for a defective alternator to supply plenty of amperage with the voltage in the basement or sky high.

 

[Slo-Sho]

I was figuring with the voltage drop through the isolator...