Independent v's Parallel Dual battery systems

Do you have any more info on the SBI12d as the Redarc site has vertualy zero info on it.?Also can you give me a price as it isnt listed on you website? And one last thing, will you ship an Fullriver AGM 90 to Adelaide?

Cheers!

Hi Bubbles

Please contact me on djbester@bigpond.net.au and I will send you any info you need.

The forum is for advice and help and is not to be used for sales.

Regards Derek.

Sorry Bubbles, I misread read your original post, and once again shot my mouth off.

Thanks very much for that Phil. Its what I was hoping to hear :)

Cheers!

No

Mike

So nothing has changed, batteries and tyres around the camp fire are as contencious as religion and politics....remember, all the isolators other than the rototronics, join both batteries together with that nice thick wire that flows 500 amps easily.....the full battery pumps as much as it can into the discharged one to equalise the volts as soon as the isolator joins them....not good for any battery.....
However, it will work for a while....
Andrew

"the full battery pumps as much as it can into the discharged one to equalise the volts as soon as the isolator joins them....not good for any battery"
- not really, just another one those Dual-Battery myths that everyone quotes, but no-one ever proves or disproves.

I've actually tested this by connecting a fully charged new AGM 90 Ahr battery to a fully discharged (to 10 volts) wet-cell starting battery. The MAXIMUM current that flowed for a few SECONDS was 32 amps, but reduced to 7 amps after 1 minute.

The total charge transferred from AGM to Wetcell was only 10.7 AHrs after being connected for 2 HOURS, this will not affect the AGM's starting ability !

Have you ever tried charging a battery with 12.6 volts ? That's all a fully charged wet-cell can put out - it won't put much charge into a battery discharged to 0% remaining.

Mike

Your experiment sounds interesting....what method did you use to measure the flow?
If you have one only gel cel in a car thats alt is pumping 14.6 into it, what fully charged voltage do u expect to see in the battery??(not surface charge, but working charge)
And if it is connected to a wet cell, with redarc or similar, what volts does it show then (again fully charged)???
If it is less, does the gel cell then never get fully charged????
Andrew

Andrew

The batteries were connected with about a 1 metre of 8g wire - so the wire resistance was 0.005 ohm. The Current monitoring shunt was also 0.005 ohm. There was a 60 amp fuse also.

Provided your Alternator has good output capability (around 80 amps) then while any batteries are connected to it (and you only have reasonable loads connected to it ) then all the batteries will see 14.4 volts. If one of the batteries is heavily discharged initially and drawing lots of current, then the voltage may be lower, but not for long.

This voltage will charge any battery after a several hours (other than Calcium-Calcium batteries). 3-stage chargers will also put out 14.4 volts in Stage 2 (depending on battery selection).

I'm surprised you are asking about a Gel Cell - they usually aren't used in Starting applications and are also prone to ovecharging more easily.

Mike

The bucket-of-water analogy just doesn't extend to batteries - if it were appropriate then a battery with 50% capacity would have to have 6 volts coming out of it - not 12 volts.

You can easily test what happens if you connect a charged and discharged battery - no-one seems to do it though.

Mike