Thread: Battery Question

Good afternoon Sir,

It's absolutely true. But don't ask me to explain.

People like Piranha and Traxide.com.au have smart chargers/isolators to prevent this from ruining your batteries and your day.

As far as i understand it, when two batteries or more are connected together in parallel they will always try to equalise each other. So if one is at 13 volts and the other is at 10 volts the battery holding more charge will top up the one with less charge untill they reach the same point. So if one battery is really bad it will knacker the other......

As I understand it, the simple ignition switch controlled isolator will try and charge both batteries when the engine is going, and if one is U/S then the second one won't get enough charging so it will then soon die or at the very least go flat.(Which can kill older batteries anyway)

Check the specific gravity and load test them at least once a year to avoid any nasty little suprises!

Traxide has a smart type charger that can avoid these problems by charging batteries intelligently, checkout Tim(drivesafe)'s website. (Traxide Tronics)

JC

(Edit, like Wild one above said!)

Mahn, that's very formal for one who has met me in the past
Thanks for the answers guys.
So even thought the traxide unit looks almost exactly the same as the one I bought from supercheap, it doesn't quite do the same job.
Looks like I'm going to have to spend more of my hard earned
My betteries both still read 12.5 volts, yet one of them won't even turn the motor over, and the other one will just crank it before failing.
Well gues I'm running one battery again.

Hi Disco95, it’s highly unlikely ( but not impossible ) that both batteries are stuffed and still holding a surface charge voltage of 12.5 volts.

If I were you I'd go and check all your cables and connects, particularly your earth connects.

If this does not solve the problem I would go to an auto electrician and have both batteries load tested but also get your starter motor checked.

Originally Posted by drivesafe

Hi Disco95, it’s highly unlikely ( but not impossible ) that both batteries are stuffed and still holding a surface charge voltage of 12.5 volts.

If I were you I'd go and check all your cables and connects, particularly your earth connects.

If this does not solve the problem I would go to an auto electrician and have both batteries load tested but also get your starter motor checked.

I had similar problem, replaced the battery but no joy, still struggled to turn the motor over, turned out to be the starter.

Originally Posted by drivesafe

Hi Disco95, it’s highly unlikely ( but not impossible ) that both batteries are stuffed and still holding a surface charge voltage of 12.5 volts.

If I were you I'd go and check all your cables and connects, particularly your earth connects.

If this does not solve the problem I would go to an auto electrician and have both batteries load tested but also get your starter motor checked.

I replaced the starter,my positive and negative leads, and ran the negative to my block. none of that made an ounce of difference, and when I put the teeny, weeny battery from my civic in, the V8 started like a new one.

After charging one of the stuffed batteries it would run the park lights but not the headlights, or the "left your lights on dickhead" alarm even.

Dsco 95,

What sort of engineer is your neighbour??

The issue of batteries trying to charge each other is true but it only happens when the alternator stops charging. While the alternator is serviceable and it is running it will provide charge to both batteries. The simplest isolators will stop batteries from equalising as that is what the isolator does isolate the batteries. If driven by the ignition switch or some voltage sensing circuit it will not matter they do they same thing. Once one of the batteries turns it's toes up then if the isolator is a simple ignition switch driven one you could get what Justin wrote happening.

Maybe you could let us in on what the device your neighbour purchased is!