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Watch those batteries.

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rfdlou

Regular Contributor
Image001.jpg This is a photo of a battery that I blew up. I was hooking up the last few wires before hitting the starter for the first time on my new engines. I was placing wires loosely on the terminal studs as I figured what went where. All went well until I connected the engine ground cable to the engine. BAM, my ears were ringing & everything including me was covered in acid. I was sitting in the bilge between the engines two feet away from it when it blew. Lucky for me my face was turned away. I grabbed the hose off the dock & blasted myself & my brand new engines. I thought, I must have connected something wrong. That was not the case. Apparently one of the first connections was the battery charger. The charger was just doing its job charging the batteries & creating hydrogen gas. When I connected the ground, a loose wire on the battery terminal arced. The rest as they say is history. You can do this stuff thousands of times & get away with it. But every once in awhile things can get real interesting real fast.
 
AGM batts are good however, they come at a premium price. If you need to fill every nook & cranny with batteries they are the only way to go. For my application 4 Walmart marine wet cells are just fine @ $75.each. I run group 27 wired together & get about 5 years out of them. Top them off with NYC tap water twice a year. The boat came with 2 8D but there way too heavy to carry to the boat & place in the bilge. The problem I had was caused by me not the battery.
 
The explosive lower and upper limits for hydrogen has about the highest range there is for commonly used industrial gases. About 10x that of gasoline, for instance. We've all done stuff more "risky" than hooking up a battery; the luck you carried had to do with your face turned away and having a good source of washdown water handy. Thanks for sharing your story!! I suppose the lesson learned is to not mess with wet acid battery terminals during and just after charging. If you look at the recent battery warning labels you might see the use of face shields and more. I'll bet most of use disregard those instructions.
 
I'm somewhat of a NAZI when it comes to battery cables, connections, etc.
IMO, it is best if we NOT have any other wire connections being made directly to our battery banks other than battery cables ONLY!

Any other power supplies can be connected directly to the rear of your MBSS (main battery selector switch) using terminals # 1 and # 2.

If we use the # 1 and # 2 terminals here, it is schematically the same as though we are making a direct battery connection.
This is an excellent location for our O/B battery charger charge leads to connect....
And for any bilge pump float switch that we want to be "un-interruptible"!

By doing so...., we avoid some of the issues that may have lead up to what occured in your case, although hard to say for sure.

We avoid the typical "Rat's Nest", small terminal corrosion, and we also avoid any confusion when replacing batteries when we have cables ONLY to deal with.

And for that matter, if this circuit is to be ON/OFF capable, we can use the "common" terminal!

(all circuits would be fused of course)

All in my opinion only..... just passing this along.
 
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RicardoMarine said:
I'm somewhat of a NAZI when it comes to battery cables, connections, etc.
IMO, it is best if we NOT have any other wire connections being made directly to our battery banks other than battery cables ONLY!

Any other power supplies can be connected directly to the rear of your MBSS (main battery selector switch) using terminals # 1 and # 2.

If we use the # 1 and # 2 terminals here, it is schematically the same as though we are making a direct battery connection.
This is an excellent location for our O/B battery charger charge leads to connect....
And for any bilge pump float switch that we want to be "un-interruptible"!

By doing so...., we avoid some of the issues that may have lead up to what occured in your case, although hard to say for sure.

We avoid the typical "Rat's Nest", small terminal corrosion, and we also avoid any confusion when replacing batteries when we have cables ONLY to deal with.

And for that matter, if this circuit is to be ON/OFF capable, we can use the "common" terminal!

(all circuits would be fused of course)

All in my opinion only..... just passing this along.
Click to expand...

I think this is a great idea, the only problem I have is my two engine switches are in the cabin, the others in the engine room. However, it is something I can begin changing too.

Exactly which terminal would the bilge pumps be connected too, the "Common"?

Thanks
 
RicardoMarine said:
I'm somewhat of a NAZI when it comes to battery cables, connections, etc.
IMO, it is best if we NOT have any other wire connections being made directly to our battery banks other than battery cables ONLY!

Any other power supplies can be connected directly to the rear of your MBSS (main battery selector switch) using terminals # 1 and # 2.

If we use the # 1 and # 2 terminals here, it is schematically the same as though we are making a direct battery connection.
This is an excellent location for our O/B battery charger charge leads to connect....
And for any bilge pump float switch that we want to be "un-interruptible"!

By doing so...., we avoid some of the issues that may have lead up to what occured in your case, although hard to say for sure.

We avoid the typical "Rat's Nest", small terminal corrosion, and we also avoid any confusion when replacing batteries when we have cables ONLY to deal with.

And for that matter, if this circuit is to be ON/OFF capable, we can use the "common" terminal!

(all circuits would be fused of course)

All in my opinion only..... just passing this along.
Click to expand...

Oh but those battery studs are right there, just under that cover all I have to do is unbuckle the strap & they have wing nuts on them just begging for a quick & easy hook up. The "grounds" or - connections are the biggest offenders. The hot wires are connected with some care but the - are all over the place on most boats.
 
I just had one blow up about a month ago. I had a trickle charger on it by my work bench and used my air cutoff grinder to cut a bolt and a spark from the grindimng wheel must have gotten over to the battery. Fortunately I had my face shield on. It took the whole top off the battery. The battery caps aren't supposed to let flame thru them as they are made with a small vent hole that doesn't goro directly down to the cells.

It's the third one I have had blow up in my 70 years. One blew up on my 1966 Pontisc GTO when the car was new. I guess the battery had a bad connection internally and genetrated a spark and it blew.

The best thing to do is hook the last cable (ground) to a remote part of the engine if possible when jumping one to prevent sparks around the battery.

Any battery even a AGM will produce some hydrogen.
 
bulletine said:
I think this is a great idea, the only problem I have is my two engine switches are in the cabin, the others in the engine room. However, it is something I can begin changing too.

Exactly which terminal would the bilge pumps be connected too, the "Common"?

Thanks
Click to expand...
I hate to see any of our MBSS's located inside of an engine bay where a hatch most be opened for access.
Not only does this make it more difficult to manage our battery banks, but makes it less accessible for an Emergency Shut-Down of all 12 v power if that need should ever arise!
I sure hope that it doesn't........ but being better prepared is invalueable!

As for the bilge pump "Float Switch"...... IMO, these should have an Un-Interruptible power supply, and from our largest battery bank.
To do this, I connect the fused lead for the float switch directly to the MBSS terminal that is in direct connection to this largest bank!
If we are going to have a float switch, it may as well be protected in-that no one can accidentally cut power to it!
And it may as well have access to the largest amp hour capacity!
I'll take a "near dead" battery bank any day, over a hull full of water.
Again, IMOO here!


rfdlou said:
Oh but those battery studs are right there, just under that cover all I have to do is unbuckle the strap & they have wing nuts on them just begging for a quick & easy hook up.
The "grounds" or - connections are the biggest offenders. The hot wires are connected with some care but the - are all over the place on most boats.
Click to expand...
Well, unfortunately, these are the owners who end up with the "Rat's Nest" at their batteries!
These smaller connections are also more subject to battery corrosion! :mad:

Like suggested, there is no need for anything other than Battery Cables at our batteries.
I think that here is a much better connecting point for these, IMO.

.
 
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Good point on having only the charger wires and battery switch cables hooked to the battery.

Another good idea is to toss those wing nuts over the side and use stainless nuts (and a flat washer) instead. You wouldn't believe how many "battery problems" are caused by those wing nuts, that never seem to get tight enough.

Glad you're okay!

Jeff
 
fastjeff said:
  1. Good point on having only the charger wires and battery switch cables hooked to the battery.
  2. Another good idea is to toss those wing nuts over the side and use stainless nuts (and a flat washer) instead. You wouldn't believe how many "battery problems" are caused by those wing nuts, that never seem to get tight enough.
Jeff
Click to expand...
  1. Jeff, I was actually suggesting that the charger leads connect to the rear of the MBSS (terminals # 1 and # 2) ... and NOT the batteries! Perhaps that's what you meant. (schematically, it is the same!) And if # 2 is our House Bank, then # 2 becomes our "un-interruptible" power for the float switch connection. Since the "Common" terminal is "interruptible", this is a great terminal for an accessory panel supply!
  2. Amen...... excellent point!
 
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Battery explosions are not uncommon...before hooking or unhooking any cable(especially Jumper cables and battery charger cables) I always make it a point to blow on the battery to temporarily remove any accumulated hydrogen and hopefully prevent any explosion. Another point is to be sure a charger is unplugged before removing it from the battery.
 
bobbyc said:
Battery explosions are not uncommon...before hooking or unhooking any cable(especially Jumper cables and battery charger cables) I always make it a point to blow on the battery to temporarily remove any accumulated hydrogen and hopefully prevent any explosion. Another point is to be sure a charger is unplugged before removing it from the battery.
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Heh, I don't disagree with you at all, those are certainly all good points.

However, the OP (rfdlou) has a 31' Chris Craft Commander 315 (1984).
If he has a charger, it's going to hopefully be a Marine O/B charger, and his connections are permanent.... of which is part of my point, with regard to the cabling and wire connections!

But good point, particularly about moving the air around a battery when connecting or disconneting cables.
 
Hey, that gives me a great idea! Instead of connecting, disconnecting the charger leads from four batteries every season, why not hook them up directly to the battery switch, where the cables coming from the batteries connect! Less chance of a mix up as well.

Consider it done.

Jeff
 
The wealth of knowledge on these pages is amazing. I have already made many of the changes suggested. Even the last set of batteries came without wing nuts just regular nuts. There is nothing smaller than a #4 cable connected @ the batteries. The #4 wiring supplying the breaker busses is on 70 amp breakers @ the battery switch. They came from the factory hooked direct to the battery no fuses. My boat also came with a factory installed charger wired direct to the batteries, no fuses. It was a monster weighed about 50 Lbs. was the size of my microwave & could cook the batteries well done if you left it on. It’s been replaced with a tiny 10 amp fully auto one, wired & fused to the master switches. Next I have to get under the dash. Since 1984 lots of stuff has come & gone. Several radios, digital depth, paper recording depth, LCD depth, color depth, GPS, GPS chart & most of the time it was just splice into an old connection. The power connections for my LORAN are still waiting should they bring my old trusted friend back.
 
fastjeff said:
Hey, that gives me a great idea! Instead of connecting, disconnecting the charger leads from four batteries every season, why not hook them up directly to the battery switch, where the cables coming from the batteries connect! Less chance of a mix up as well.

Consider it done.

Jeff
Click to expand...
Bingo! It's the perfect location, Jeff..... and it's permanent, and the MBSS can be set to "OFF", and all O/B charger "charging" still takes place.


rfdlou said:
...............
It’s been replaced with a tiny 10 amp fully auto one, wired & fused to the master switches.

Next I have to get under the dash. Since 1984 lots of stuff has come & gone. Several radios, digital depth, paper recording depth, LCD depth, color depth, GPS, GPS chart & most of the time it was just splice into an old connection. The power connections for my LORAN are still waiting should they bring my old trusted friend back.
Click to expand...
Yep, you now have "Smart Charge" technology, and it is unlikely that you will damage your batteries from this type of charger.
(10 amps may be a little bit on the light side, however)

Just a suggestion: You have an oportunity to run yourself a new "dedicted" circuit forward for all of your navigation equipment, if you choose to.
You'd take a "Negative" as well as "Pos" forward to a small 6 gang (or ????) breaker or fuse panel.
(I've done this on mine as seen at Stbd side of photo)
I now have an individual circuit for each radio (including AM/FM) and nav equipment, plus a power port.
It piggy-backs to the upper station as well.

In essense, I'm no longer relying on the hull harness for this power.
This can also be powered from the MBSS "common" terminal if you want this to be interruptible when the MBSS is "OFF".

Just a suggestion!
 
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