DIY Electric Car Forums banner

1 - 2 of 2 Posts

·
Registered
Joined
·
70 Posts
Discussion Starter #1
I made my own plasma today.

I was driving home...I did my usual 65 mph stint on the freeway for 12 miles
and then slowed to about 50 mph on the local road. The last mile or so at 65
mph, I smelled something so I eased up on the pedal. I smelled it again when
I accelerated from a stop light to 50 mph so I detoured to a 25 mph road
that would get me home the last 2 miles.

I accelerated to 25 mph from a stop sign and heard a zzzZZZZZTT- POW! and I
saw a brief, white puff of smoke and had a total loss of power. I hit the
hazards and slewed into a parking lot. I popped the engine lid and found an
8v floodie with the positive lug blown clean away and a shattered case up
top. Melted lead spray was on the inside of the engine lid, but no acid
spray even though the caps were blown off. The interconnecting cable was
HOT. Pretty dramatic.

Here's a little history: This battery had a loose cable a few weeks back.
The negative lug melted down a little but there was still a lot of usable
material. It wasn't bad so I tightened it down. The postive lug is the one
that blew apart. I routinely check the water levels and voltage levels once
a month. There was nothing out of the ordinary. The Zivan charger keeps
things pretty balanced and I've only had to add water once since March.

My theories are:

1. I overloaded the battery by pulling 80-300 amps (hills) doing 65 mph on a
hot summer's day. A plate warped and shorted out against another plate.
2. I overheated the battery and the lead lug simply boiled away.
3. I overloaded the battery and caused a cell reversal. (on a 128v pack, I
never pull below 115 volts for 1.8 vpc so I don't consider this likely)

I had a spare battery at home and these are still under warranty so I'm
already back on the road. I just want to know what I did wrong so I don't do
it again. Please post your theories.

Rich "plasma-wannabe" Acuti
Maryland

_________________________________________________________________
Don't get caught with egg on your face. Play Chicktionary!*
http://club.live.com/chicktionary.aspx?icid=chick_hotmailtextlink2
 

·
Registered
Joined
·
70 Posts
Discussion Starter #2
Hello Richard,

Installing new batteries or new links, tighten to 75 inch lbs if it's a
battery clamp. Stud type connections are rated from 60 to 75 inch lbs to
105 inch lbs., but I never take the studs over 75 inch lbs.

Now drive five miles and re-torque again. You will find you will loss about
5 inch lbs on the initial run. Then check the it again at 10 miles where
some will loss about 1 to 2 inch lbs. Again in 20 miles and they should
stable out.

What happens is that the surface of the lead is not a true mirror surface
where there may be surface scratches that melt back or we call shrink back.

I use a solid brass battery clamp that has grooves in to the inside surface.
This gives more surface area in the contact area. Also I install the
battery clamp pressing down on the base of the offset pad if you have one,
which gives more contact area.

I use a battery post that has a stud coming out the top, but I do not use
this stud to connect a link to. But I do install a stainless steel washers,
lock washer and nut and torque this stud to 75 inch lbs after the battery
clamp is torque first.

This tightening of the stud, puts internal pressure of the lead post against
the inside of the battery clamp and keeps the top of the post from
mushrooming out the top of the battery clamp. The last time, I t initial
torque the battery clamps, was in 2005 and they are all between 70 to 75
inch lbs.

Roland


----- Original Message -----
From: "Richard Acuti" <[email protected]>
To: <[email protected]>
Sent: Monday, July 30, 2007 7:21 PM
Subject: What exactly happened? (Battricide)


> I made my own plasma today.
>
> I was driving home...I did my usual 65 mph stint on the freeway for 12
> miles
> and then slowed to about 50 mph on the local road. The last mile or so at
> 65
> mph, I smelled something so I eased up on the pedal. I smelled it again
> when
> I accelerated from a stop light to 50 mph so I detoured to a 25 mph road
> that would get me home the last 2 miles.
>
> I accelerated to 25 mph from a stop sign and heard a zzzZZZZZTT- POW! and
> I
> saw a brief, white puff of smoke and had a total loss of power. I hit the
> hazards and slewed into a parking lot. I popped the engine lid and found
> an
> 8v floodie with the positive lug blown clean away and a shattered case up
> top. Melted lead spray was on the inside of the engine lid, but no acid
> spray even though the caps were blown off. The interconnecting cable was
> HOT. Pretty dramatic.
>
> Here's a little history: This battery had a loose cable a few weeks back.
> The negative lug melted down a little but there was still a lot of usable
> material. It wasn't bad so I tightened it down. The postive lug is the one
> that blew apart. I routinely check the water levels and voltage levels
> once
> a month. There was nothing out of the ordinary. The Zivan charger keeps
> things pretty balanced and I've only had to add water once since March.
>
> My theories are:
>
> 1. I overloaded the battery by pulling 80-300 amps (hills) doing 65 mph on
> a
> hot summer's day. A plate warped and shorted out against another plate.
> 2. I overheated the battery and the lead lug simply boiled away.
> 3. I overloaded the battery and caused a cell reversal. (on a 128v pack, I
> never pull below 115 volts for 1.8 vpc so I don't consider this likely)
>
> I had a spare battery at home and these are still under warranty so I'm
> already back on the road. I just want to know what I did wrong so I don't
> do
> it again. Please post your theories.
>
> Rich "plasma-wannabe" Acuti
> Maryland
>
> _________________________________________________________________
> Don't get caught with egg on your face. Play Chicktionary!
> http://club.live.com/chicktionary.aspx?icid=chick_hotmailtextlink2
>
>
 
1 - 2 of 2 Posts
Top