Danger Warning ACR's

[ontherocks83]

Originally Posted by btrayfors

Ontherocks83,

You could use a Balmar DuoCharge device (as mentioned by the OP) in lieu of the Echo Charge. Here's the manual for that device: www.balmar.net/PDF/Duo%20Charge%20Manual.pdf

The DuoCharge costs about twice what the EchoCharge goes for, but it is more sophisticated in that it can be programmed for any battery chemistry and it has a temp sensor option which when activated "cuts off charging current" to the start battery.

Bill

Thank you. I just read the manual from your link and that seems like a really good fit for what I want to do. Thanks for the info!!

[Dockhead]

Originally Posted by Maine Sail

Perhaps someone can clear up for me how one bank, in parallel, can be at 11 volts, and a VSR, which cuts out at about 12.85V to 13.0V would remain connected...? That one has me stumped...

If the banks are in parallel, and one batt is at 11V, there is no ACR connection for very long, unless someone re-wrote Ohm's Law while I was sleeping.......

I am guessing that it would happen like this --

The charger is holding the system at float voltage when suddenly a chunk of lead falls off a plate and shorts out one cell of one batt.

This pulls down the system voltage, but not far enough to disconnect the ACR. Remember the charger is on! Voltage gets down into bulk charging range, and the charger switches to bulk mode, blasting all of its amps into the system.

I can easily see that all those amps -- especially if there are healthy batteries in parallel -- could easily keep the system voltage above the level where the ACR cuts out.

And as Nick has pointed out, if there are healthy batteries in parallel, amp/hours stored in them will also be dumped into the system, also tending to keep the voltage up.

[Maine Sail]

Originally Posted by Dockhead

I am guessing that it would happen like this --

The charger is holding the system at float voltage when suddenly a chunk of lead falls off a plate and shorts out one cell of one batt.

This pulls down the system voltage, but not far enough to disconnect the ACR. Remember the charger is on! Voltage gets down into bulk charging range, and the charger switches to bulk mode, blasting all of its amps into the system.

I can easily see that all those amps -- especially if there are healthy batteries in parallel -- could easily keep the system voltage above the level where the ACR cuts out.

And as Nick has pointed out, if there are healthy batteries in parallel, amp/hours stored in them will also be dumped into the system, also tending to keep the voltage up.

Exactly!

I was just clearing up that one battery was not at 11V when the ACR was made. That can only happen temporarily and cause relay cycling. The ACR needs to be above 12.85V or so to remain connected and the large current source was likely a major contributor here.

Because this was a large current source it was able to maintain the ACR in parallel at obviously above 12.85V - 13V....

A smaller current source would likely not have held the ACR in parallel feeding into a dead short because it would not have had the current behind it to maintain the combine voltage.......

[ksanders]

I'll repeat what others have said.

Unless there was a temperature sensor on EVERY battery that was tied to a disconnect for that battery the scenario the OP presented is unavoidable.

The source of the charging current is not relevant to the issue, therefore the ACR in and of itself cannot be at fault.

And yes, I do this for a living.

[ontherocks83]

[QUOTE=ksanders;1458577]Unless there was a temperature sensor on EVERY battery that was tied to a disconnect for that battery the scenario the OP presented is unavoidable.QUOTE]

Is there a way to do this?

Do they make separate inline auto disconnects with a temp sensor or would the charger have to be designed for it?

Also if the charger would have to be designed for it then what happens when you are using the alternator to charge?

[btrayfors]

[QUOTE=ontherocks83;1458587]

Originally Posted by ksanders

Unless there was a temperature sensor on EVERY battery that was tied to a disconnect for that battery the scenario the OP presented is unavoidable.QUOTE]

Is there a way to do this?

Do they make separate inline auto disconnects with a temp sensor or would the charger have to be designed for it?

Also if the charger would have to be designed for it then what happens when you are using the alternator to charge?

Well, there is a way at least with the alternator.

The Balmar MC-612 and MC-614 smart regulators have connections for three temperature sensors: (1) an alternator temp sensor; (2) battery #1 temp sensor; and (3) battery #2 temp sensor.

Other smart regulators may have one or more of these connections.

Re: battery chargers, I would use only one of the multi-outputs if your charger has more than one. Run it to the house battery bank, and use a DuoCharge (or an EchoCharge) to maintain the start battery.

Bill

[ontherocks83]

[QUOTE=btrayfors;1458606]

Originally Posted by ontherocks83

Well, there is a way at least with the alternator.

The Balmar MC-612 and MC-614 smart regulators have connections for three temperature sensors: (1) an alternator temp sensor; (2) battery #1 temp sensor; and (3) battery #2 temp sensor.

Other smart regulators may have one or more of these connections.

Re: battery chargers, I would use only one of the multi-outputs if your charger has more than one. Run it to the house battery bank, and use a DuoCharge (or an EchoCharge) to maintain the start battery.

Bill

So in a setup where you have a 2 battery house bank can you connect lead (2) to one of the house batts and lead (3) to the other house batt in the same bank? and then have a duocharger with a temp sensor for the start batt?

[btrayfors]

[QUOTE=ontherocks83;1458620]

Originally Posted by btrayfors

So in a setup where you have a 2 battery house bank can you connect lead (2) to one of the house batts and lead (3) to the other house batt in the same bank? and then have a duocharger with a temp sensor for the start batt?

Not sure what you mean by "lead (2)" and "lead (3)".

Please clarify -- exactly what is meant by these terms. Are you talking about the charging cables (positive and negative)? The connections to the DuoCharge? The multiple output (charging) wires from the battery charger???

Bill

[ontherocks83]

[QUOTE=btrayfors;1458631]

Originally Posted by ontherocks83

Not sure what you mean by "lead (2)" and "lead (3)".

Please clarify -- exactly what is meant by these terms. Are you talking about the charging cables (positive and negative)? The connections to the DuoCharge? The multiple output (charging) wires from the battery charger???

Bill

I was going off of your post where you wrote (1) alternator, (2) battery and so on....sorry i assumed those were the numbers or designations of the wires coming out of the charger and going to their designated spots.

[btrayfors]

[QUOTE=ontherocks83;1458640]

Originally Posted by btrayfors

I was going off of your post where you wrote (1) alternator, (2) battery and so on....sorry i assumed those were the numbers or designations of the wires coming out of the charger and going to their designated spots.

The Balmar regulators can take up to three temp sensors, as follows:

1. an alternator temp sensor attached to the case of the alternator itself;

2. a battery temp sensor attached to (the negative pole of) any battery; and

3. a second battery temp sensor attached to (the negative pole of) any other battery.

Normally, one temp sensor would be attached to the start battery and one to the house batteries, i.e., to any battery in the house bank.

That's not 100% protection, of course, but it's pretty good.

Bill

[Hyprdrv]

I have 12 AGMs in series for a propulsion bank.
I have a Brusa charger. The charger doesn't step back to a previous program. In other words the charger won't step back From Trickle charge to bulk charge ever unless disconnected from shore power and reset. This, at first, I thought was going to be an issue until I thought about thermal runaway. At 2/3 amps trickle (programmable) I couldn't "cook" the batteries.

The Brusa has 3 Temp. sensers. Obviously still not enough in my case but better than 1. Each senser is placed between 2 batteries, in effect covering 2 batteries or a total of 6.

These chargers cost BIG bucks. 8O)

Steve in Solomons MD

[ontherocks83]

[QUOTE=btrayfors;1458646]

Originally Posted by ontherocks83

The Balmar regulators can take up to three temp sensors, as follows:

1. an alternator temp sensor attached to the case of the alternator itself;

2. a battery temp sensor attached to (the negative pole of) any battery; and

3. a second battery temp sensor attached to (the negative pole of) any other battery.

Normally, one temp sensor would be attached to the start battery and one to the house batteries, i.e., to any battery in the house bank.

That's not 100% protection, of course, but it's pretty good.

Bill

OK I understand that set up thank you.

Now forgive me for asking another question but would it not work to put one temp sensor to the negative of one of the house batteries and one temp sensor to the negative of the other house battery? Obviously in a 2 battery house bank set up.

My thinking would be that if I am using a duo charger that has its own temp sensor for the start battery I would have an extra temp sensor, so theoretically could I attach the other temp sensor to my second house battery?

I apologize for beating the horse here I'm just trying to wrap my head around everything. I appreciate your responses and time.

[btrayfors]

[QUOTE=ontherocks83;1458651]

Originally Posted by btrayfors

OK I understand that set up thank you.

Now forgive me for asking another question but would it not work to put one temp sensor to the negative of one of the house batteries and one temp sensor to the negative of the other house battery? Obviously in a 2 battery house bank set up.

My thinking would be that if I am using a duo charger that has its own temp sensor for the start battery I would have an extra temp sensor, so theoretically could I attach the other temp sensor to my second house battery?

I apologize for beating the horse here I'm just trying to wrap my head around everything. I appreciate your responses and time.

No need for an apology.

Yes, that would work OK. Then, you'd be pretty well covered with temp sensors.

Hate to mention this, but in the real world all temp sensors are not created equal.

• They can measure too low temp, leading to overcharging.
• They can measure too high temp, leading to undercharging.
• They can do nothing.

That's just the reality of things. YMMV :-)


Bill

[donradcliffe]

Forget the temperature compensators--just put the batteries in an acid-proof, fire-proof, explosion-proof enclosure--the Boeing solution.

[Cheechako]

Curious.. have others noticed more dead shorted batteries that were 8D in size? Based on my life sample, I've had two 8D's that were near new dead short. I think I've had 3 8D's in my life.