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battery fire

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To simply protect against this type short-requies that a high amperage aircraft type circuit breaker be installed in the short ground return lead between the cut off switch and the chassis ground in the boot.

Additionally, and also quite simple to implement is to install a battery with the terminal posts located on the opposite side which places the terminals away from the hold down bar- works a treat.

Keeping the battery connections sorted can be done by obtaining those little green - and red + felt washers that fit around the battery terminals underneath the bolt on connectors.
 
I saw this box of parts being sold with a BJ8 on BringATrailer. Look at the item on the top of the picture with the words "Safety Cover" on it. Does that look like a cover that might have gone over the terminals of the battery? Anyone seen anything like it before?

19533980336_7c3b582177_b.jpg
 
i absolutely agree that some fuses would save significant risk of recuurence and give me peace of mind. Bob, I notice that you have some insulating material between the long bolt holding down the battery and the positive battery cable. That is another great idea! I agree, in hindsight, that buying a car like this from one of these high end dealers has been less than. Great experience. I bought it in April and have already replaced a radiator and found other more minor issues in a car that was supposed to be properly sorted, then had this issue! Keoke, I'll definitely clean up the acid as suggested. Thanks again everyone! Brent
 
HI Rick

I have seen those used on batteries that have both top and side connectors. When the side connectors are used this gadget shields the top exposed terminals from accidental short circuits.
 
When I decided to convert my BJ7 to negative ground I was concerned that the battery post were now on the same side as the battery hold down. I figured that it easily could work loose and then make the contact between the post. If I turned the battery around it caused cable routing issues I didn't like so I decided to let the battery post be on the same side as the hold down. But to try to build in some safety features, I coated the hold down bar with pored rubber material used to coat tools, and then put some large dia. heat shrink material on the ends of the bar. That at last resort I added the cork to the location of the positive terminal in case the bar had enough movement that it might wear thru my coating and slip under the battery post connector.
this thread has reminded me to check my arrangement for tightness. Dave.
 

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If I turned the battery around it caused cable routing issues

That is true Vette.
However, some batteries are available with reversed terminals which will accomplishes moving the terminals away from the battery clamp.

Both the Group 24 and 27 batteries are available this way.
 
If you get the smaller size battery(I use NAPA), and the original type hold downs (Moss), you can move the battery forward enough to put two plastic quarts of oil under the hold downs next to the battery. This holds them securely. I also put the hold downs in 1/4 inch diameter clear plastic tubing (local hardware store). I also replaced the nuts with wing nuts to allow for faster removal of the battery when the boot gets soaked in the rain (been chasing that leak for many years).
TH
 
In the original set up, the bolts go into metal bracing, not the tray. In my boat, i glued the tray that steveg is showing to the floor.
 
Braindoc2be said:
Here is kind of a stupid question: I see that the bolts hold the battery to the tray,
but what holds the tray down?
Click to expand...

The weight of the battery reinforced by the downward pressure applied by the battery clamp'
 
Keoke,

You mentioned an aircraft circuit breaker as a simple solution for protecting the battery circuit of the Healey. I have tried to find additional information and costs for such a circuit breaker but have not as yet found something applicable. Since the draw of a starter can be as much as 480 Amps at 12 Volts (much less for a gear reduction starter) and since many of us have also installed an alternator that can generate as much as 80 amps, sizing the circuit breaker is beyond my expertise and would appreciate help. Our hot lead in our Healeys extending from the battery to the starter (with circuit extending to the generator/alternator) and runs along the lower section of the frame. This hot cable placement makes it possible to strike the cable and stripping the insulation sufficient enough to create an arch with the grounded frame.

A properly sized circuit breaker, placed between battery ground and frame, would cut the circuit in case of a short. However, if the starter requires 480 amps to start the engine, a substantial amount of damage could be caused before the circuit breaker faults if sized to the starter plus a reasonable buffer. So, what size would circuit breaker would you suggest? Can you point to an appropriate example of the circuit breaker?

Thanks and all the best,
Ray (64BJ8P1)
 
Can you point to an appropriate example of the circuit breaker?

There are vendors such as Buss man and Schneider Electric producing relatively small single
breakers that can be paralleled to meet that current level.
Some of the individual breakers will handle 150 Amps..

Cost today is about $40.00 or more each.

For short circuits that do not occur right at the battery -"like your create an arch with the grounded frame"- you must remember that the wire conductor will immediately begin to heat increasing its resistance and power consumption and may continue to do so until the wire melts.
Here under a worst case scenario the wire becomes the fuse.

The simplest solution Still:
Is to use a battery having reversed terminals.
This allows you to position the terminals immediately adjacent to the wooden block and away from the metallic battery hold down.
 
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Ray, Just for conversation sake, I'd like to talk about this overload protection scheme that you have been envisioning. Oh but first I have to say that in regard to the positioning of the battery terminals in the Healey trunk, I remember now that one of the reasons that I installed my battery with the terminals to the left side is that I did not like how close they were to the side inner rear fender panel when the battery was turned around with the terminals to the right side. It made it harder to work on them and it made it harder to insulate/isolate them. Anyway back to the question of overload protection for the main battery cable. Unless I am building something custom I am usually just restoring and in restoring I usually defer to the designs of the original designers and engineers. So with this battery cable I have often wondered how many of these cables have ever been faulted to short to the frame and cause catastrophic damage. It seems in my experience, not very often. Now I agree the positioning of the cable at the bottom of the frame is not ideal. But I believe that if you study closely the original positioning of the cable that the cable was installed with wire clips that positioned the cable up along the side of the frame in most situations. Granted this doesn't help much but it does preclude somewhat that the cable would be smashed against the frame. Without building a very complex electrical system with ground fault measuring and relay tripping it would be very problematic to install a protective system for this cable. And considering the incidence of occurrence of this kind of fault it would seem very impractical. I have spent most of my life working with a large electric utility, I installed electrical metering arrangements in all kinds of facilities from 138 thousand volt sub stations to the largest commercial customers we had. There are some electric services that are considered too necessary to allow to fail. Which means you keep the power on no matter what. (within reason). To do that you build it bullet proof. It is so heavy (electrically) and so strong that it will not interrupt. And you serve it to the customer with NO FUSING. An example is fire pumps in large industrial and commercial facilities. These pumps are served on their own cables with no fuses straight from the utilities facilities. These pumps must run in the event of fire or flood damage or more catastrophic damage would occur. So they will run until they destroy themselves or the service cable supplying them would be destroyed. My point is, the solution to the Healey battery cable protection in my opinion is to build it strong. If you look at the picture of my battery and notice the red (positive) cable going to the front of the car, that cable is NON-STOCK because it is a very specially insulated very strong cable covering. I believe a rock could hit that many times and the insulation will never break and short to the frame.
I even contemplated running it in conduit, but thought that would really be overkill. But that wouldn't be hard to do. Strap the conduit to the side of the frame and the cable would be protected for most of its length. But in reality it may be less protected that way. A good rock hitting the conduit may crush the conduit and then pinch and fault the wire. I believe my use of the heavily re-enforced insulation of the cable I used is the best practical way to protect against possible fault of the main battery cable. Dave.
 
"There are some electric services that are considered too necessary to allow to fail."

YEP
However, since you do not generate the power distributed to you the power generating/distribution system itself can fail.

For example a single strike of lightening can disable the best power distribution system we have.

Recognizing this uncontrollable area of nature we install on site large backup power generators that automatically come on line in the event of such a power failure.
 
Braindoc2be said:
Sorry, here is a pic of the pre-fire trunk I found from the ad when I bought the car:
attachment.php
Click to expand...

I just noticed something about this picture. Although the red protective cover is over the positive terminal, that's the ground lead, not the hot one. Shouldn't a cover have been on the other terminal in a positive ground car?
 
You are correct Rick. Also notice that instead of the tray, the battery is sitting on two stacked pieces of narrow wood. That, coupled with the rubber tie-down and that battery was surely flopping around as the car drove down the road.
 
Hey Greg & Rick:

Glad you guys saw those suspicious bits in the picture. I did not blow it up,but my gut feel said that battery moved. I did not know whether it grew legs or just slid but it had to move.

It is interesting to note here that the initiation of most electrical failures is a mechanical one.

Consequently, adding a lot of mechanical bits to an electrical circuit can be counter productive.
 
So the best CSI guess is that either the battery shifted and the negative terminal (hot one that was left uncovered) grounded to the frame through the J hook or alternatively, a loose metal object made contact with the negative terminal and frame. It's worth noting the factory setup included a battery tray to support the battery, two J hooks that attach to mounts in the frame, a top bracket and wing nuts. And as added protection, a vinyl cover that went over the top of the battery to protect the terminals from contact. If you're trying to keep it looking stock, you could use the original hardware while coating the top bracket with plastic as vette did, protect the terminals with terminal covers and drop the vinyl battery cover over the top to hide the terminals. At the other end of the protection scale would be a marine style plastic battery box, properly mounted, but then we'd have to start another thread about whether we'd have to vent it.
 
Yes, the battery was sitting on top of a piece of 2x6 inside the battery tray. I don't really know why... The tray was not held down by anything that I could tell and I am not sure what the bolts were hooked to that supposedly held the battery in place. There is one hole in the side of the battery tray that could accommodate one of the bolts (though that wouldn't stop the tray from moving) and there did not appear to be anything on the alternate side. Thus, I am suspicious that the other bolt wasn't attached or wasn't attached to anything that I could find. I absolutely agree with the general consensus: the battery was mobile and allowed the negative post/cable to ground out -> fire!
 
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