Last night - 10 PM got a call from my CS monitoring company

[pete_c]

Here have two same sized batteries in one HAI sub panel.
 
I had decided to use an old battery.  I checked the voltage before connecting it and it sat at about 2 VDC.  I should have thrown it out as it was already in the discard pile.
 
I forgot about the call and did notice the main pain panel was showing a fault this afternoon.  Well I have never seen a battery do this (see pictures).
 
I took pictures before the discard.  Waiting any longer and I probably would have messed up the supply voltage and or other battery.  This is my fault and relating to not paying attention.
 

 

[drvnbysound]

I've seen batteries in an UPS do this when they overheated... it made getting them out of said UPS pretty difficult!

 

[ano]

Just wondering, why do you use two batteries in parallel rather than a larger battery?  This might seem like a good idea, but typically it isn't.
I think you have discovered what can happen. Normally a failed battery just drops in voltage but with a good battery powering it, the bad battery heats up.  At the very least add a fuse for each battery, maybe a 2A fuse for the Omni would be good. That way the fuse on the good battery would blow before overheating the bad battery.  I'm surprised the battery wire didn't melt.  
 
Oh, and NEVER use a 12V battery that measures 2V.  Did you mean 12V?  12V would be the VERY minimum.  Lower than that and its a BAD battery.

 

[mikefamig]

I'm guessing that one or two of the cells shorted but I'm surprised that the battery charger on the panel had the power to do that. I suppose that it doesn't take all that much power to melt a battery case.
 
Mike.
 
EDIT
 
After reading what ano said I see that it was the other battery that did the damage and not the panel.

 

[pete_c]

It happened in less than 24 hours.  I had left the old battery on a shelf instead of throwing it out.  It looked new yesterday except for the voltage part.
 
Yes the two battery leads come right from the sub panel with no fuses on each of them. (soldered in to place).  Thank you Ano I am going to go to one battery..
 
This panel isn't really busy like the main panel.  Initially just installed one battery.  Over time I should have just put a larger battery in.  I am using the same battery size for the main OPII can.  But that one is overflowing today.

 

[mikefamig]

I used two batteries in my system because the cabinet is not deep enough for a very large battery but wide enough for two.
 
Mike.

 

[ano]

You could also add a small battery idolator in your box if it fits.  As drvnbysound says, I have seen UPS manufacturers place batteries in parallel like this but it is a bad thing to do in my opinion. 

 

[ano]

I used two batteries in my system because the cabinet is not deep enough for a very large battery but wide enough for two.
 
Mike.

If you do, it would be smart to add a fuse to each battery. Pete said it took 24 hours for the battery to heat so maybe it wouldn't have blown the fuse anyway, but it doesn't hurt.

 

[pete_c]

Just changed the OP as it was 2222C when I got the call.  It felt like 3AM because I had fallen alseep already.  You know how old people go to bed early.
 
I installed it some time in the morning yesterday...I wanted to see if it would get charged such that I left the door open on the standard sized OmniCan such that the battery was sticking out of the can adjacent to the other battery. 
 
A few months back I tried another battery that was sitting on the shelf.  It was taller so it wouldn't really fit under the panel inside the can.  It didn't take a charge; but it didn't rupture and I threw it out.
 
I also have some UPS (big UPS) batteries that I was going to check out.  These though are too big and look like little car batteries.
 
 
Message from CS was:
 
On Tue, Mar 22, we received the following signal from your alarm system indicating a maintenance problem with your equipment. Many issues such as low batteries can easily be fixed by you, while others may require the help of a local alarm technician.
 
What is a small battery idolator?

 

[drvnbysound]

What is a small battery idolator?

 
https://en.wikipedia.org/wiki/Battery_isolator
 
Pretty common in multiple battery vehicles.

 

[ano]

https://en.wikipedia.org/wiki/Battery_isolator
 
Pretty common in multiple battery vehicles.

It would separate the two batteries, but in hindsight, it may not work here the way you want.  So ignore that solution. 
 
Best, get a bigger battery, but I know they don't always fit.  If you do use two batteries, make sure they are both new and replace them at the same time. Don't mix an OLD battery with a NEW battery.

 

[Del91574]

Pretty common occurence on old SLA's that are past their expiration date. Pete's battery was already deep cycled so a goner before even attempting to charge.
 
Swelling is charged by overheating generally. A bad battery heats up a LOT. Causes the case to swell. They don't really melt, but are softened by the heat and either they balloon or they split.
 
Putting batteries in parallel really isn't a huge deal. No faux pax. Just need to make sure they're matched so a push-pull doesn't occur. Fusing is generally desirable but not a must.

 

[pete_c]

Thanks guys.
 
Mike described on another post the MB engine and aux battery thing.  In the 1960's we had a motor home with two batteries in it.
 
Here I installed a tank battery on first automobile I put a car PC in.  I did utilize a UPS style battery for endeavor.

 

[mikefamig]

I don't believe that the MB batteries are simply connected to each other in parallel. The engine start battery in the engine compartment is 350AH while the consumer battery in the trunk is 700 AH. I have never looked at a wiring diagram for the car but I am guessing that they are isolated from each other.
 
Mike.

 

[pete_c]

Yeah the tank battery I installed years ago came with a circuit board which allowed for charging the battery and it was only connected to the computer.  It was a Via Epia CPU based motherboard at the time.
 

 
I would guess that the MB batteries are isolated and not wired in parallel.
 
The HAI subpanel here has two sets of battery cables by default.  The panel is a touchscreen and video hub.  (with a daughter board) in a standard HAI can (same one as the OmniPro 2).  I am using this for the OmniTouch 5.7 / video screens and this is mixed in with an Axis server, Grandstream encoder/decoder, ZM NVR and HD IP and Analog cameras.