[Bugsta]

I am planning to change the original wet battery in the Jim to a sealed unit and add an AGM and a full electronic control system. I have read the recent comparo of 'Dual battery Isolators' in 4WD Action, and the 2 that stood out were the redarc BMS1215 at $1595 and the Autron BMS2000 at $299. I like the idea of alternate charge methods that the redarc unit offers and the nice LCD readouts.

Is there perhaps any other units on the market that offer specs between these 2?

[Scrawny]

We use Redarc on all our hire vehicles that run dual batteries, never had any problems with them. I've also fitted a TJM unit that didn't seem too bad

[Bugsta]

Good to hear Scrawn.

I would love to use it, but I kinda don't want to spend $1600.

[royce]

that redarc setup is more for caravans and stuff that have multiple charging inputs, simple smart solenoid style of thing will do the trick nicely

better yet make the AGM removable and leave it in the shed hooked up to a Ctek charger while you dont need it, they are bloody heavy and seem to cark it when underbonnet mounted pretty quickly

[zookster666]

TJM units are pretty good there is an ibs and a dbs unit. Both work well and when installed right work great.
The ibs unit has charge displays on it aswell as 2 buttons to manually or automatically link the batteries.
The dbs unit only has 2 buttons to manually or automatically link the batteries.

[oozuk]

royce wrote:

that redarc setup is more for caravans and stuff that have multiple charging inputs, simple smart solenoid style of thing will do the trick nicely

better yet make the AGM removable and leave it in the shed hooked up to a Ctek charger while you dont need it, they are bloody heavy and seem to cark it when underbonnet mounted pretty quickly

X2 on the smart solenoid setup, alot cheeper and can be setup as a jumpstart function with the way it's wired for the occasion that your main battery goes flat you can pres a button and connect both the batteries together and then start your car

[zukenutter]

Solenoid will be the way I go next time around. I have a lower spec Rotronics battery isolator. There's no option for starting off the second battery.

[royce]

zukenutter wrote:

There's no option for starting off the second battery.

I had my 1 litre setup so that everything bar the starter was wired to the aux battery so leaving lights on, running stereo etc wasnt a drama, if the battery got that flat that it couldnt click the solenoid in when the ignition was on I pressed a button and it linked em back up, no fancy electronics needed

[steve]

yeah i have the solinoid thing on the buggy for the second battery, works awesome, dunno why anyone would bother with the fancy systems?

[Trojan]

steve wrote:

yeah i have the solinoid thing on the buggy for the second battery, works awesome, dunno why anyone would bother with the fancy systems?

There is the starting issues with just a solenoid that is triggered off the ignition system. The whole "equalisation" thing isn't much of a concern if you have something that doesn't struggle to start.

The more concerning one is that it can potentially hide the presence of a faulty main battery. You could have no starting issues and still have a faulty main battery which can't start your engine. You then go and drain the second battery whilst camping to a point it won't start you're vehicle, try to start and it's at this point you discover you're main battery is stuffed and could have been for quite some time.


The main reason i have a "smart solenoid" in our Prado. Is the additional capacity you get from the batteries not diconnecting from each other until the voltage drops a little. Comes in handy when camped in the one spot for several days and not needing to start up to recharge batteries for that bit longer.

[royce]

thats sales bullshit made up by companies selling that stuff, youll never get enough current through the solenoid or the cabling to make any difference at all, ive tried

[Trojan]

royce wrote:

thats sales bullshit made up by companies selling that stuff, youll never get enough current through the solenoid or the cabling to make any difference at all, ive tried

Depends on what size you go and use now, doesn't it.

[royce]

Dont edit your post when I am trying to quote you, the errors make me nervous!!!!!

no it wont cause end of the day it still wont start, even using a 1000amp solenoid and massive cables, if the main battery is screwed it wont start

[Trojan]

royce wrote:

no it wont cause end of the day it still wont start, even using a 1000amp solenoid and massive cables, if the main battery is screwed it wont start

So you have a main battery which dies under load and parrelel a good charged second battery to it and the vehicle will never ever start?

[steak_knife]

royce wrote:

Dont edit your post when I am trying to quote you, the errors make me nervous!!!!!

no it wont cause end of the day it still wont start, even using a 1000amp solenoid and massive cables, if the main battery is screwed it wont start

X2, have to swap batt's over, main batt will just suck all the aux's power.

[Trojan]

steknig wrote:

royce wrote:

Dont edit your post when I am trying to quote you, the errors make me nervous!!!!!

no it wont cause end of the day it still wont start, even using a 1000amp solenoid and massive cables, if the main battery is screwed it wont start

X2, have to swap batt's over, main batt will just suck all the aux's power.

Yet that same principal magically doesn't work the other way when the aux battery is drained? Technically the equalisation happens, but if the vehicle starts fairly easily under normal circumstances, you won't notice it or have a chance for it to problematic.

[royce]

Trojan wrote:

steknig wrote:

royce wrote:

Dont edit your post when I am trying to quote you, the errors make me nervous!!!!!

no it wont cause end of the day it still wont start, even using a 1000amp solenoid and massive cables, if the main battery is screwed it wont start

X2, have to swap batt's over, main batt will just suck all the aux's power.

Yet that same principal magically doesn't work the other way when the aux battery is drained?

your only talking maybe 30amps running across batteries, if your aux battery is dead but not destroyed flat and you link the batteries for a perios of time before engaging the starter you might have some dramas but in real life its unlikely

same reason that jump starting a vehicle with a flat battery never works battery to battery you always run the jumping vehicle for a bit to get some zap back into the battery

[steak_knife]

Trojan wrote:

steknig wrote:

royce wrote:

Dont edit your post when I am trying to quote you, the errors make me nervous!!!!!

no it wont cause end of the day it still wont start, even using a 1000amp solenoid and massive cables, if the main battery is screwed it wont start

X2, have to swap batt's over, main batt will just suck all the aux's power.

Yet that same principal magically doesn't work the other way when the aux battery is drained?

Glad you used that word, cause that's what it dose, you can even put a jump pack on it, or if you like, use 20 batt's & jumper lead's, still won't start if the main batt is fucked.

But if you do believe in magic than it will work fine..

[Trojan]

royce wrote:

same reason that jump starting a vehicle with a flat battery never works battery to battery you always run the jumping vehicle for a bit to get some zap back into the battery

I've jump started battery to battery on several occasions, so it does work. Comes down to the vehicle and the reason why you're battery isn't up to task of starting. There are several reasons why a wet cell battery can be faulty.

Some of tnose of those reasons are going to make themselves evident regardless, others can potentially can be masked. Seen it happen on several occassions also, not so much in automotive situations directly as such, but on more then one occassion a good battery hiding a faulty battery on the starting system of diesel engines. Only became evident after removing and load testing the batteries on routine maintanance schedules.

So i will remain to the fact that a normal solenoid set up can mask a dud main battery. Not every time, but the potential is there.

[steak_knife]

Trojan wrote:

royce wrote:

same reason that jump starting a vehicle with a flat battery never works battery to battery you always run the jumping vehicle for a bit to get some zap back into the battery

I've jump started battery to battery on several occasions, so it does work. Comes down to the vehicle and the reason why you're battery isn't up to task of starting. There are several reasons why a wet cell battery can be faulty.

Some of tnose of those reasons are going to make themselves evident regardless, others can potentially can be masked. Seen it happen on several occassions also, not so much in automotive situations directly as such, but on more then one occassion a good battery hiding a faulty battery on the starting system of diesel engines. Only became evident after removing and load testing the batteries on routine maintanance schedules.



So i will remain to the fact that a normal solenoid set up can mask a dud main battery. Not every time, but the potential is there.

There you have it then, are you talking, Boat's? Earth moving? Generator's?

[303zuke]

steve wrote:

yeah i have the solinoid thing on the buggy for the second battery, works awesome, dunno why anyone would bother with the fancy systems?

The solenoid system is reliable and cheap to replace components, but the opening and closing of the contact can cause voltage spikes and Rf interference that will root an EFI computer, and that is where the fancy electronic types are recommended.
So it comes down to: Do you have an EFI or Carby vehicle?

[royce]

303zuke wrote:

steve wrote:

yeah i have the solinoid thing on the buggy for the second battery, works awesome, dunno why anyone would bother with the fancy systems?

The solenoid system is reliable and cheap to replace components, but the opening and closing of the contact can cause voltage spikes and Rf interference that will root an EFI computer, and that is where the fancy electronic types are recommended.
So it comes down to: Do you have an EFI or Carby vehicle?

what about the spike from the starter solenoid?
what about the alternator 'surge' when you flash the high beams?

the big voltage smoothing device known as the battery gobbles it up

I had an EF alternator on my EFI vit that was stuffed and doing funny things that made lots of headlight globes blow, usually a pair at a time and there were no EFI parts going up in smoke

[Bugsta]

Quote:

yeah i have the solinoid thing on the buggy for the second battery, works awesome, dunno why anyone would bother with the fancy systems?

How about... COS I CAN!