12v Battery Charger?

[sublib25]

Don't know if we have covered this subject, reading around gives multiple recommendations.
Whats the best/average/$$ wise charger to maintain automotive batteries in a dual battery system.

Looking at the Projecta PC800.

Advice appreciated.

[sublib25]

Well... went to get dot 3 brake fluid - clutch & brake flush.
Repco had 30% off for RACQ members, one on the shelf, listed at $189.
Will see how it goes.....

[Tiny]

I have a Projecta IC1000, that works excellently, however in my 2 battery system on the Land Cruiser the resistance thru the Red Arc VSR between the 2 batteries is enough to prevent it switching from charging the starter battery to charged, then absorption & then float, unless I disconnect the Aux Bat.
It just stays on absorption as it cant meet the 20w threshold to switch to float even if I separately charge the Aux & Starter first.
No probs the other way round, so the resistance is only one way, as it probably should be on this particular dual system.

So I have to maintain them separately.
A quick look at the PC800 & it may do the same, so test it as above.

Don't get me wrong though; the charger is excellent & it's not able to know there is a VSR in line that presents some resistance.

[bob_m_54]

I have a Projecta IC1000, that works excellently, however in my 2 battery system on the Land Cruiser the resistance thru the Red Arc VSR between the 2 batteries is enough to prevent it switching from charging the starter battery to charged, then absorption & then float, unless I disconnect the Aux Bat.
It just stays on absorption as it cant meet the 20w threshold to switch to float even if I separately charge the Aux & Starter first.
No probs the other way round, so the resistance is only one way, as it probably should be on this particular dual system.

So I have to maintain them separately.
A quick look at the PC800 & it may do the same, so test it as above.

Don't get me wrong though; the charger is excellent & it's not able to know there is a VSR in line that presents some resistance.

From the way I'm reading your post, you are saying that when you connect your charger to the START battery, the VSR operates (because the input voltage exceeds 13.2V) and the battery charger sees a contact resistance between the two batteries, that prevents it from going into float stage?

If I have that correct, how old is the VSR? It may have high resistance contacts caused by arcing during switching.

I use a C-tek 7amp charger to charge my AUX battery sometimes, which I connect via a 50A Anderson plug located at the front of my engine bay. (the A plug is connected to the AUX battery via an 80A CCT breaker).
Sometimes I might give the START battery a charge as well, which I do by momentarily pressing the start assist button, after I connect the charger to the AUX battery (via the A plug). This operates the solenoid, which is then held in by virtue of the higher than 12.7V input from the charger. This is probably not ideal, being that the two batteries are different types, but it does seem to work OK and eventually will go into float mode, but it takes a long time depending on the state of charge of both batteries.

[Tiny]

From the way I'm reading your post, you are saying that when you connect your charger to the START battery, the VSR operates (because the input voltage exceeds 13.2V) and the battery charger sees a contact resistance between the two batteries, that prevents it from going into float stage?

If I have that correct, how old is the VSR? It may have high resistance contacts caused by arcing during switching.
.

Yes you have that correct bob; the VSR is of unknown age, was in the vehicle when i bought it second hand 11 years ago & it's a 1996 LC GXL, so who knows how old it is.

I gave it 24 hours & it would not go into float even with both bats charged fully & floating separately before connecting in that config again.

[bob_m_54]

Yes you have that correct bob; the VSR is of unknown age, was in the vehicle when i bought it second hand 11 years ago & it's a 1996 LC GXL, so who knows how old it is.

I gave it 24 hours & it would not go into float even with both bats charged fully & floating separately before connecting in that config again.

With the AUX battery less than about 70% charge, check the voltage drop across the two studs on the solenoid while charging, you should have less than about 100mV. Do it without the charger connected, just using the alternator charging for max current.

[loanrangiel]

I never need to boost my aux. battery in my disco, 14.4V from the alternator does that quick enough. The Piranha isolator has been moved across a few vehicles and still does its job and at a guess its about 20-25 years old.

[Tiny]

I never need to boost my aux. battery in my disco, 14.4V from the alternator does that quick enough. The Piranha isolator has been moved across a few vehicles and still does its job and at a guess its about 20-25 years old.

I do; as I use my winch around my property a lot, which even with motor running pulls the aux down a fair way.
Also it can sit for a month without use at times so battery management is important to extend the life of the batteries.

[loanrangiel]

My winch is only powered by main batt, then its always got power and wont flatten the aux. which is really only for my 50ltr fridge. Camper trailer has a 145AH battery for the fridge and lights when we are camped.

[ol' boy]

Don't know if we have covered this subject, reading around gives multiple recommendations.
Whats the best/average/$$ wise charger to maintain automotive batteries in a dual battery system.

Looking at the Projecta PC800.

Advice appreciated.

I know you've purchased the Projecta
But many friends in the 4WD, Street Car and Racing game are very happy with their CTEK chargers.
There is so many different models though



Hope the Projecta serves you well, good price.