AGM PARRELL with acid crank ?

Submitted: Sunday, Mar 12, 2006 at 17:34
ThreadID: 31674 Views:2009 Replies:4 FollowUps:7
This Thread has been Archived
have just purchased 2 agm batteries (exide orbital ) want to parellel one as aux under the hood and one in ct , I have a acid battery as my crank want to know can i still use my over ride switch to draw power from battery bank if crank battery gets low ?,hope i've made sense
thanks tony
Back Expand Un-Read 0 Moderator

Reply By: Derek from Affordable Batteries & Radiators - Sunday, Mar 12, 2006 at 17:55

Sunday, Mar 12, 2006 at 17:55
Hi Tony,

What isolator are you using and what thickness wire ?

Are you fitting fuses ?

Also if you intend to crank off the auxillary battery is there an isolator between the trailer and the car to prevent melt down of cables.

Regards Derek.
AnswerID: 160100

Follow Up By: Member - Tony W (VIC) - Monday, Mar 13, 2006 at 04:45

Monday, Mar 13, 2006 at 04:45
isolator not sure ,will have to check
fuses yes
ive got 6mm at the moment ,in the process of upgrading to 10mm
0
FollowupID: 414825

Follow Up By: Derek from Affordable Batteries & Radiators - Monday, Mar 13, 2006 at 07:17

Monday, Mar 13, 2006 at 07:17
Hi Tony,

To can't crank through fuses or 6mm wire. Best to use good jumer cables.

The 10mm wire is great for the charge set up. 6mm is a bit light for the long run to the trailer.

Regards Derek.
0
FollowupID: 414829

Follow Up By: VK3CAT - Monday, Mar 13, 2006 at 08:48

Monday, Mar 13, 2006 at 08:48
Hi Tony & Dereck. Don't want to steal your thread but I am doing something similar with my 80 series. I have a Wet Lead acid cranking battery & a Full River AGM deep cycle battery. I have had to move the auxillary power switchboard - using Clipsal DC circuit breakers & an isolation switch - in order to fit an ARB compressor under the bonnet for future diff locks. Anyway, I use 25 square mm tie cables between the batteries so cranking off the auxillary is not a problem. What I am trying to work out are the pros & cons of standard solonoid isolators against smart ones.
Using the Redarc SB112 as an example, I gather that it will isolate the auxillary battery until the cranking battery reaches 13.6 volts and then remain energized (as long as the ignition is on) unless the cranking battery voltage goes below 12.7 volts?
Surely with an alternator output close to 14 volts, the cranking terminal voltage will very quickly reach the nominated 13.7 volts & then energize to enable charging to the auxillary battery? The only circumstance that I can envisage when this may not happen is when the cranking battery is just about stuffed. Am I correct in this thinking?

Am I better off with a non smart (dumb?) solonoid such as the Redarc SL-100 to use for dual battery starting? Or, should I be looking at something with a higher continious current rating? (SL 12-100 & SB112 both being rated at 100 amps continious & 400 amps peak)

PS, as far as I can tell, the 80 series 1HZ diesel motor is pretty basic without serious computer control, thus surge suppression maynot be such an issue? Dereck, the battery article is a good read!
Cheers Tony - VK3CAT http://www.qsl.net/vk3cat
0
FollowupID: 414839

Follow Up By: Derek from Affordable Batteries & Radiators - Monday, Mar 13, 2006 at 09:04

Monday, Mar 13, 2006 at 09:04
Hi Vk,

No you are wrong. The Redarc , Sidewinder and ABR units cycle on and off as needed.

My own system in my 100 series will not charge the auxillary when the lights are on and the a/c is on.

These 'Smart' systems are better.

When using a 'Basic' on / off system you will run the auxillary down when driving in the rain, a/c on, high beam on and wipers on.

Regards Derek.
0
FollowupID: 414841

Follow Up By: Mike DiD - Monday, Mar 13, 2006 at 11:10

Monday, Mar 13, 2006 at 11:10
Tony

As Derek's example shows, a Voltage-sensing Solenoid does have two advantages when the demand exceeds the Alternators charging ability - when this happens the Alternator can no longer maintain its rated output - 14.0 to 14.4 volts and the lower voltage will make the solenoid open.

This means that the Auxiliary will not be discharged (even if it is only slowly) but also protects the Alternator from high loading by removing the Auxilairy Battery as load.

Mike
0
FollowupID: 414868

Follow Up By: Mike DiD - Monday, Mar 13, 2006 at 11:15

Monday, Mar 13, 2006 at 11:15
"the battery article is a good read! "

- I agree, this is now a very good introduction to auxiliary power. It is understandeable by anyone without needing technical kowledge.

Mike
0
FollowupID: 414870

Reply By: Member - Norm C (QLD) - Sunday, Mar 12, 2006 at 23:29

Sunday, Mar 12, 2006 at 23:29
You should be able to crank off the one under the hood without problems. To prevent cable problems to the CT, I'd just make sure the Anderson Plug to the CT was disconnected when you did it, so you do not draw from that battery.

Since the need for this should be rare, you could always rely on the good old jumper leads to keep your set up simple.
AnswerID: 160160

Reply By: Member - Tony W (VIC) - Monday, Mar 13, 2006 at 04:47

Monday, Mar 13, 2006 at 04:47
cheers norm
AnswerID: 160173

Reply By: Sand Man (SA) - Monday, Mar 13, 2006 at 10:51

Monday, Mar 13, 2006 at 10:51
Tony,

I would not recommend "paralleling" the Orbital and Start battery.
What is the purpose of you wanting to do this?
Why would your cranker get low, unless you are running other accessories (perhaps a winch) off it? Well just make sure your have the engine running when using a winch. (The winch should be connected directly to the primary (Starter) battery.

Connect the batteries via a smart isolator and you can charge the primary first, followed by the auxiliary, whilst you are driving. Both batteries will last a considerable length of time.

The other orbital in your camper would most likely need the inclusion of an Arrid twin charge, (or equivalent) which will overcome voltage drop problems, that would otherwise limit a proper charging current to the battery in the Camper.
The twin charge will accept a lower input voltage (From the long run from your vehicle) and boost the output so that the battery receives an appropriate charge.

If your Starting battery somehow dies when you are in a remote area, you can temporarily exchange it for one of the Orbitals. It doesn't take much to physically connect another battery rather than "flick a switch".

Keep it simple and follow the tried and tested pattern mate.
Bill


I'm diagonally parked in a parallel Universe!

Member
My Profile  My Blog  My Position  Send Message

AnswerID: 160201

Follow Up By: Member - Tony W (VIC) - Monday, Mar 13, 2006 at 16:06

Monday, Mar 13, 2006 at 16:06
Sandman
sometimes the best ideas are the simplest ,until next time thanks to everyone for their input .
Tony

0
FollowupID: 414939

Sponsored Links

Popular Products (13)