Gerald Miller wrote:

On Tue, 15 Feb 2011 21:42:45 -0500, "Michael A. Terrell"
wrote:



My first car (61 Ford Galaxy) had an odd electrical problem that
would kill the battery, and several mechanics gave up on finding the
cause. My first clue was that you could listen to the radio by turning
on the parking lights, and turning on the left turn signal. The tail
light had a dead short between the two filament terminals. It took me
longer to replace the lamp and lens than it did to find the trouble. My
uncle was upset, because he sold the car for $100, since no one could
fix it.
Senior son had a 68 firebird that had to be driven every day to keep
the battery charged. After several rescue calls, I traced the problem
to a rusted out horn relay.


The battery in my 66 GTO would be dead if it sat more than a few
days. That turned out to be a bad battery cable. The insulation had
turned to carbon, and was draining the battery. It ran trough a metal
tube to keep it away from the engine, so the damage wasn't visible until
it was removed from the car. The new cables were made from #1 welding
cable, and the electrical system had about 5 microamps leakage after the
repairs.


--
You can't fix stupid. You can't even put a band-aid on it, because it's
Teflon coated.

On Thu, 17 Feb 2011 09:51:31 -0600, Ignoramus5243
wrote:

On 2011-02-17, Pete C. wrote:

Ignoramus20463 wrote:

On 2011-02-16, wrote:
On Tue, 15 Feb 2011 06:03:50 -0800 (PST), Jim Wilkins
wrote:

On Feb 15, 8:51??am, Ignoramus20463 ignoramus20...@NOSPAM.
20463.invalid wrote:
...
No, blue top is deep cycle. Yellow top is deep cycle plus cranking
duty. Red top is cranking only. I just got a yellow top battery for
myself today, cannot wait to get it.

i-

http://www.optimabatteries.com/home.php
With spec sheets and instructions.

jsw
OK, just picking one size out of the mix - a group 34.

The Blue 34M is 1000ca, 800cca, 100 reserve, 50 reserve @ c/20. 0.003
ohm resistance and 38.4 lbs.
The red 34 or 34R are also 1000 ca, 800cca, 100 reserve, and 50
reserve @c/20 with 0.003 ohms resistance, and is half a pound ligher
(aprox) at 37.9 lbs

The yellow D34, on the other hand, is only 750 ca, and 870cca, but has
a 120 minute reserve and 55 reserve @ c/20. The resistance is also
lower at 0.0028 ohms, and it weighs a whopping 42.9 lbs - in the same
sized case.

These numbers tell you what the advertizing does not. The YELLOW top
battery is THE deep cycle battery.
The red top and the blue top are extremely close in both construction
and specification and are heavilly biased in their design to motor
starting duty.
The blue battery has a bit more weight than the red one, which points
to a slighly more deep-cycle design than the red one, all else being
the same.


Very good. These dischares really do ruin regular starting batteries.

i

You might want to look at a different inverter, many have a low voltage
shutoff feature to turn them off at something like 11V to prevent deep
discharge damage.

I agree with you. I will look into this.

i

You might also want to measure the actual current your inverter draws
from the power source as all (particularly cheap Chinese) inverters
are not created equally and some of the cheaper ones actually draw
more current then larger (better designed) ones with the same load.

I have a laptop and sometimes I forget to turn off the inverter for
it. If I had extra capacity, I would be better off with that.

Would you be better of building a DC-DC converter for the laptop
instead of running DC-high voltage AC only to transform it back to
low voltage and rectify it again? If your charger uses a proprietary
connector instead of the typical barrel setup (or a "smart" battery
minder) maybe you could find a spare charger and hack it to accept
14.4V input...?

While it would be less convenient (building a new converter every time
you get a new laptop that takes a different voltage) I can't help but
think it would be at least a little bit more efficient...

--Glenn Lyford

On Fri, 18 Feb 2011 06:37:39 -0800, Glenn Lyford wrote:
On Mon, 14 Feb 2011 19:26:55 -0600, Ignoramus14196 wrote:
I have a laptop and sometimes I forget to turn off the inverter for it.
If I had extra capacity, I would be better off with that.

Would you be better of building a DC-DC converter for the laptop instead
of running DC-high voltage AC only to transform it back to low voltage
and rectify it again? If your charger uses a proprietary connector
instead of the typical barrel setup (or a "smart" battery minder) maybe
you could find a spare charger and hack it to accept 14.4V input...?

While it would be less convenient (building a new converter every time
you get a new laptop that takes a different voltage) I can't help but
think it would be at least a little bit more efficient...

Here's a source for the necessary connectors and parts ...
http://www.powerstream.com/ADC.htm ... just find your
laptop on the list, get the corresponding converter, and
then you can cut it up for the parts and connector to build
your own converter.

--
jiw