Thread: Simple solenoid dual battery set up

Originally Posted by 86mud

Hi all

Did a quick search but was unable to find an exact answer...

On my old range rover I had a simple heavy duty solenoid for my dual battery set up and never had a problem in 4 years.

The battery box in my DEF130 is a wiring nightmare with some weird looking dual battery controller that I think has finally died. I purchased new batteries just after I bought the truck in April and my aux battery is now not charging.

I am going to rip out all the dodgy wiring and go back to a simple solenoid.

Can anyone give me the cons of using a heay duty solenoid?




The two large terminals are for each +ve battery lead, one small terminal is an earth and the other small terminal is to ignition.

Cheers
Andrew

There is nothing wrong with this set up. I have been using one of these since 1993. First on my RR and now on my disco.

When I had it on my rangie I had it wired to my ignition switch. I once left my ignition on and flattened both batteries.

When I put it on the disco I connected it to the alternator so it only connects when engine is running.

When I purchased mine it came with a Diode across the small terminals. I was told this was to prevent a spike when ignition was turned on. I'm guessing this would not be necessary when wired to the alternator as it is charging at the same time it is connecting the two batteries.

Can post pics if you want.

Dave.

I have an SC40. Quite happy with it.

Thanks for all your responses.

the current unit that is in my truck comprises of two components - one looks like a type of solenoid and one looks like a type of controller all connected with wires going everywhere. I will take a photo on Saturday to explain.

It currently has a lead coming from the alternator which I take it activates the control unit.

In my old Rangie I had the ignition from the coil and never had a problem in four years.

I looked at the SC40 & SC80 on the Traxide site. I also looked at the Baintech units. So now I have 3 choices!!!!

Cheers
Andrew

Originally Posted by Vern

Why is that? I have both and both work fine, prefer the way the electronic one charges the main battery first though!

Why.... Most Alternators are more than capable of charging both Batteries at the same time.
So your controller is charging the main battery first while the Alternator ticks along with 30 AMPS of more of spare capacity. Like I said electronic controllers are a waste of money.

Here is the best Aux battery setup coming from an Avionics Engineer...

.

Out of interest Andrew,
what are your requirements?

For our style of weekend camping / touring / week long fishing trips I have no need for isolated batteries but a need for maximum winching current.

In the 130 I run two N70 marines parralleled with heavy cable. All accesories including fridge run off the two batteries.

Weekend camping, no worries, engine will always be started before the battery bank is even close to being discharged. Touring same thing, from two big marines our SS40 Engel will go 2.5 days and the fender wont even stutter on start... most touring stops for us are less than that, and the longer ones always require a firewood run or some such. And on week long fishing camps, well no dual battery system will simply allow for that so you need external power. We use a honda.

BUT when winching is required, two parralelled N70s will give more poke than any isolated system, besides a complicated system where you put in a manual switch to join them for winching.

I use to use a rotronics with one cranker and a deep cycle batt, but get more fridge run time out of two N70 marines. Just have a voltmeter you can check on until you know the current draw of the fridge.

Simplicity

S

Requirements are:

80 litre waeco
Roof mounted DVD player for the kids
two Burn Bright fluro lights http://www.burnbrite.com/pdf/TNB8%20...Lead-Light.pdf

and a shower pump made using a small bildge pump.

The lights would only be used for say 4 hours at night and the pump would be running continuously for say 20 minutes (2 kids + adults) max at night.

Cheers
Andrew

here are some pics of the current set up/mess...

once I position the new solenoid, I might get myself a fuse block and tidy up the wiring as well..

Originally Posted by buzz66

Why.... Most Alternators are more than capable of charging both Batteries at the same time.
So your controller is charging the main battery first while the Alternator ticks along with 30 AMPS of more of spare capacity. Like I said electronic controllers are a waste of money.

Here is the best Aux battery setup coming from an Avionics Engineer...

.

didn't really tell me why an electronic one is a waste of money