Blue Sea ACR-S vs T-MAX dual battery

[n00g7]

It doesn't' t have a choice if your winch is wired off of the primary.

It's bi-directional. As long as high current draw of winch doesn't cause voltage across terminals of winching battery to drop below lockout threshold it would combine for 10/30 seconds it seems based on spec sheet, but you'd just override it in that scenario.

 

[Douglas S]

I only saw the unit in the original post , a 120 amp ACR. I went to the Blue Sea site and saw the 7620, 500 amp version. It's a little more spendy
at 250.00+. But if it won't let the main battery drop below 12.7 it wouldn't allow winching off it. It would be cool if it had a manual override on the circuits. The description states...automatically combines batteries during charging and isolates batteries when discharging and when starting engine. I wonder if your can use the "emergency" setting to parallel the batteries for winching

The 7622 is the unit with manual override.

 

[Dave 2000]

The 7622 is the unit with manual override.

I purchased and installed my 7622 unit around five years ago My LC 80 thread.

The specs are IIRC for 500 amp so winching not an issue.

So we understand why I made this modification, I will go over a couple of points. I mentioned earlier having the heavy relay or solenoid whatever it was I had years back on my Land Rover and it worked fine and will satisfy 'most' peoples requirements. With the engine running it would parallel the batteries and disconnect when switched off however, what if you needed the extra power to jump start yourself? Easy, you fit a switch and then forget to switch it off, mine is a big red light in the centre console, hardly going to miss this lit up when the batteries are paralleled. So for a non techie install, you fitted a heavy duty solenoid, then you fitted an override switch, and then you fitted a big red light.....you can see where this is going right? Now tell me if your setup will do this?

For me to go camping without a fridge is not an option, I pull up on site and switch off the engine, the solar panel takes over charging duties and covers the draw from the fridge but, as there is an excess of amps it also charges the battery, the ACR detects the rise in voltage and parallels the two batteries, both batteries are now on charge. The sun goes down and the draw from the camp lighting/fridge start to pull the volts down, not particularly fast as two batteries are carrying the load. Eventually the voltage drops enough to cause the ACR to separate the batteries, fridge and lighting load on 'aux' battery, starter battery protected from the draw. Sunrise and the panel starts the process again, I can camp for days like this. So what if there is insufficient sun? No problem, I can start the engine and use the surplus from the 150 amp alternator at idle to charge the batteries. During this entire episode I have done nothing...............NOTHING.

The 7622 does it all for me period. A glance at the NL monitor on the centre console tells me the status of both batteries but if there was a problem an alarm will sound anyway, the Blue Seas manual override switch sitting in 'AUTO', I need not worry about anything. I cannot do without the security of a second battery or the security of a system that will always ensure that the starter battery is protected. It fits 'my' needs perfectly, being designed for the marine environment quality and longevity is ensured, five years on and counting with no issues whatsoever, I have witnessed many failings on various systems designed for 4x4's, some fail because of quality issues, and to be fair many fail from the poor installation.

Make your decision based on your personal needs, the thickness of your wallet, but most important of all, take note of the people who have installed the gear and have some evidence and a track record with it, and not just heard about a friends mate who knew someone related to his fathers daughter who fitted a such and such gadget.

regards

Dave

 

[lcwizard]

sounds like a cool toy. That's nice it has an override. My solar panel is only attached to my secondary battery that's powering the ARB fridge...
I'm with Dave 2000 in that I've got so spoiled with my fridges, anything more than a 12 hour camping trip and it goes with me. Both my ARBs
are nearing 20 years old and run 24 hour a day either plugged into 12 or 120 volt. I buy a lot of Blue Sea product like fuse boxes and such.
I'm Ok with the setup I use but you do have to be vigilant. With a solenoid that automatically parallels the batteries when the key is turned
you don't know for sure if one or the other is dying or dead. Either battery may be starting your truck. I carry a voltmeter in the truck but I also use an in dash meter with a toggle to verify voltage in either before starting. Of course few people would do this every time but on camping
trips I make a point of it. The price of the 7622 isn't all that bad considering a 500 amp solenoid is at least 80 dollars for Chinese one and about 250 for the top of the line Gigivac

 

[Dave 2000]

Something I meant to add, the solenoid system mentioned earlier can have a switch to force the two batteries together but, what if the battery that supplies the solenoid switch with voltage dies? You start messing around with jump leads or get the spanners out. The Blue Seas unit has a manual button, open the bonnet and press, now both batteries are in parallel again. There is a physical lockout facility as well, this can be used to prevent the batteries joining. I did press it once to see if it works and it does, that was a few years back though. Again the very fact that the 7622 works seamlessly in the background of using the car you actually forget about it's functions.

A further note about the NL monitor, before Xmas last year I jumped in the car and noted the batteries had been disconnected during the night, and this is not uncommon if I left the car for a few days, the parasitic draw of the clock, alarm and so forth causes the ACR to split the batteries. But overnight this was unusual, the batteries had been in there approaching IIRC four years? So monitoring the NL I kept an eye on the batteries, the ability to compare both batteries at the same time is a distinct advantage with this unit. Over a couple of days I noted the 'aux' battery was taking longer to recharge, and if left overnight would lose enough voltage to prompt the ACR into action. This was my warning the 'aux' battery life was coming to an end, this made sense as it has been exposed to a current draw most of it's life from the above items, the starter battery having done just that with no other parasitic draw when the engine was off. I purchased TWO identical batteries and gave the original's to a local guy who collect scrap, the result was 'normal service has resumed'.


regards

Dave

 

[n00g7]

Something I meant to add, the solenoid system mentioned earlier can have a switch to force the two batteries together but, what if the battery that supplies the solenoid switch with voltage dies? You start messing around with jump leads or get the spanners out.

Open circuit voltage would still cause the relay to close and as soon as that occurs it would stay on due to formed connection with other battery. For example, when a battery dies you can hear the starter relay click rapidly when you try to start the car -- voltage across battery is enough to close relay but as soon as load is applied to battery (starter) it pulls the voltage below the ON voltage for the relay and it opens.

 

[Dave 2000]

Open circuit voltage would still cause the relay to close and as soon as that occurs it would stay on due to formed connection with other battery. For example, when a battery dies you can hear the starter relay click rapidly when you try to start the car -- voltage across battery is enough to close relay but as soon as load is applied to battery (starter) it pulls the voltage below the ON voltage for the relay and it opens.

Which I guess is why you have the ability to use a physical override, what is the point otherwise? Once the button is pressed it stays in, you have to rotate the cam to release it manually.

regards

Dave

 

[n00g7]

Which I guess is why you have the ability to use a physical override, what is the point otherwise? Once the button is pressed it stays in, you have to rotate the cam to release it manually.

regards

Dave

It's so you can close them if the electronics on the unit fails (or don't have the switch connected to force closed), not because it won't close if a battery has a low voltage.

The relay flutters when starting a dead battery because of current draw by components controlled by the relay when it closes causes the voltage to drop. As for the battery relay, since the other battery delivers power as soon as the battery relay is closed that would not happen.

 

[Dave 2000]

You are losing me here, I know how it works but guessed the button on the 7622 is a manual override if the electronics fail or a battery is dead, the whole point of having a manual override.

IIRC, I can remove the cables to the starter battery and press the manual button, and then start from the aux battery, which is what it was designed to do right? Not with the car at the moment but I will check tomorrow, I will remove one or both connections and see what the units response is. My thinking is someone out at sea with a non starter and who knows nothing about electrics could be guided to press a button to start the engine. Given boat batteries are below deck and in enclosed places, it makes no sense to be playing with jump leads, the chance of an explosion a very real possibility.

Get back to you,

regards

Dave

 

[n00g7]

You are losing me here, I know how it works but guessed the button on the 7622 is a manual override if the electronics fail or a battery is dead, the whole point of having a manual override.

IIRC, I can remove the cables to the starter battery and press the manual button, and then start from the aux battery, which is what it was designed to do right? Not with the car at the moment but I will check tomorrow, I will remove one or both connections and see what the units response is. My thinking is someone out at sea with a non starter and who knows nothing about electrics could be guided to press a button to start the engine. Given boat batteries are below deck and in enclosed places, it makes no sense to be playing with jump leads, the chance of an explosion a very real possibility.

Get back to you,

regards

Dave

You have a button and also a remote switch.

Issue 1: dead battery can explode, although unlikely, this is why you'd want to use the remote switch if at all possible to connect them.
Button - Mechanical override, this would allow you to connect the batteries if electronics/remote switch malfunction. If you disconnected a lead on the dead battery, you could start the engine from the aux battery WITHOUT charging the dead battery through the mechanical override as well (e.g., by disconnecting ground terminal) - safe.

Issue 2: gas discharge from charging battery can ignite. For this reason battery storage compartments are required to be ventilated. It would not be the cause of a dead battery explosion, but rather if one caused a spark while battery was charging.

In terms of a simple solenoid relay, if the "electronics" fail, you're SOL. Provided the electronics do not fail, a remote switch could provide same operation as the remote switch with the blue sea unit.

As for pros of the blue sea unit over the solenoid relay in a basic 2 battery configuration (e.g., just accessories ran off 2nd battery), you don't have to wire anything other than the switch to the leads out of the blue sea unit itself.

 

[Dave 2000]

Yes I have the remote and the physical button.

The relay contacts are enclosed so no exposed risk of sparks, using spanners/jump leads adds to the risk. There is no physical button on an ordinary solenoid, batteries that are discharging also give off hydrogen gas, bang! Agreed they should be ventilated but, I have seen two batteries explode, one next to a generator outside, and the second (caused by me) under the open bonnet of a small Ford, i.e. neither in the hull or bilges of a boat.

The typical 'home' solenoid relay system cannot shine a light on the facilities you get with the Blue Seas unit period.

regards

Dave

 

[n00g7]

batteries that are discharging also give off hydrogen gas, bang!

Not true, water is a product of battery discharge, in charging it's a reactant and can be electrolyzed to produce excess H2 and 02.

 

[Dave 2000]

Not true, water is a product of battery discharge, in charging it's a reactant and can be electrolyzed to produce excess H2 and 02.

So your OK with the part where I said "The typical 'home' solenoid relay system cannot shine a light on the facilities you get with the Blue Seas unit period."? Good.

It has always been good practice when jumping a car that is not starting due to a flat battery to ALWAYS put the negative to another part of the engine away from the (flat) battery, in case there is hydrogen present which could ignite.

So to correct my previous paragraph to that line, what I should have said is 'a discharging battery due to a faulty cell gives off explosive gas'.

My apologies.

regards

Dave

 

[n00g7]

So your OK with the part where I said "The typical 'home' solenoid relay system cannot shine a light on the facilities you get with the Blue Seas unit period."? Good.

It has always been good practice when jumping a car that is not starting due to a flat battery to ALWAYS put the negative to another part of the engine away from the (flat) battery, in case there is hydrogen present which could ignite.

So to correct my previous paragraph to that line, what I should have said is 'a discharging battery due to a faulty cell gives off explosive gas'.

My apologies.

regards

Dave

"So your OK with the part where I said "The typical 'home' solenoid relay system cannot shine a light on the facilities you get with the Blue Seas unit period."? Good."

Depends what you're looking for out of it, winch and aux power it makes no difference other than if it "breaks."

"It has always been good practice when jumping a car that is not starting due to a flat battery to ALWAYS put the negative to another part of the engine away from the (flat) battery, in case there is hydrogen present which could ignite."

Just attach leads to bad battery first and to good battery second, this puts you even further away from the bad battery incase of failure.

 

[Dave 2000]

n00g7 said 'Depends what you're looking for out of it, winch and aux power it makes no difference other than if it "breaks.'

Exactly my point, pay for the Blue Seas and the likelihood of failure is very unlikely, of course go ahead and fit a low buck Chinese POS, jump leads in the trunk (they sell them cheap as well) and your good to go.

n00g7 said 'Just attach leads to bad battery first and to good battery second, this puts you even further away from the bad battery incase of failure.'

Oh right.................I get it........connect to the battery that IS charging and giving off the explosive gas Hydrogen............you know.......the one you told me would be doing exactly that, make up your mind my friend.

regards

Dave

 

[n00g7]

n00g7 said 'Depends what you're looking for out of it, winch and aux power it makes no difference other than if it "breaks.'

Exactly my point, pay for the Blue Seas and the likelihood of failure is very unlikely, of course go ahead and fit a low buck Chinese POS, jump leads in the trunk (they sell them cheap as well) and your good to go.

n00g7 said 'Just attach leads to bad battery first and to good battery second, this puts you even further away from the bad battery incase of failure.'

Oh right.................I get it........connect to the battery that IS charging and giving off the explosive gas Hydrogen............you know.......the one you told me would be doing exactly that, make up your mind my friend.

regards

Dave

Rofl, Dave, Dave, Dave, it's embarrassingly simple: you don't attach the jumper cables while the vehicle is running.

 

[Dave 2000]

So that I and everyone has it clear

You state: 'A battery discharging does not give off hydrogen gas'

I state: 'It can if a cell is faulty and why we put the negative cable to earth away from the battery'

At this point you have conceded there is a risk by suggesting an alternative however, you are unable to 'put your hands up' and actually say it. Instead you state: 'put the leads on the dead battery and then on to the good battery.'

I state: 'This is more dangerous as it will be giving off Hydrogen gas' (which you agree to).

Then you come out with this ridiculous answer:

'Rofl, Dave, Dave, Dave, it's embarrassingly simple: you don't attach the jumper cables while the vehicle is running. '

So, now us stupid people are to believe there is no chance of an explosion from a battery just come off charge (i.e. just turned off the engine of the donor vehicle), if we create a spark next to it, which is a very real possibility engine on or off right?

Are you honestly and seriously saying that? I could have course misunderstood, but I know that your last sentence is complete bollocks!

You have painted yourself into a corner my friend, stop now before someone writes a letter to the head of the organisation, that awarded your degree in Electrical Engineering, and tells them they made a mistake, and that they should rescind it!

I am done with this thread!

regards

Dave

 

[n00g7]

So that I and everyone has it clear

You state: 'A battery discharging does not give off hydrogen gas'

I state: 'It can if a cell is faulty and why we put the negative cable to earth away from the battery'

At this point you have conceded there is a risk by suggesting an alternative however, you are unable to 'put your hands up' and actually say it. Instead you state: 'put the leads on the dead battery and then on to the good battery.'

I state: 'This is more dangerous as it will be giving off Hydrogen gas' (which you agree to).

Then you come out with this ridiculous answer:

'Rofl, Dave, Dave, Dave, it's embarrassingly simple: you don't attach the jumper cables while the vehicle is running. '

So, now us stupid people are to believe there is no chance of an explosion from a battery just come off charge (i.e. just turned off the engine of the donor vehicle), if we create a spark next to it, which is a very real possibility engine on or off right?

Are you honestly and seriously saying that? I could have course misunderstood, but I know that your last sentence is complete bollocks!

You have painted yourself into a corner my friend, stop now before someone writes a letter to the head of the organisation that awarded your degree in Electrical Engineering, and tells them they made a mistake, and that they should rescind it!

I am done with this thread!

regards

Dave

You can still connect jumper to chassis ground at the donor vehicle last to avoid creating a spark at the good battery. Regardless, it's the dead battery that's at risk of exploding upon charge, not the good one discharging once the connection is formed. See ya.

 

[half k cruiser]

Who gives a $hit ^ lets get back on topic. I ordered the 7622 and will figure out how i'm going to wire it up when it gets here. I think I will probably throw down the clams and get one of the dual batt monitors like was mentioned above. I saw a National Luna one today and was impressed by the small size and seeming quality of construction. Might go with it, or the NOCO.

 

[jtwopark]

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