In my case it's an Onan genset with an Onan Elite E140H 14 HP engine.
The generator is a Pro 6000E Model EGHEB

The former owner had alligator clips on the battery cables that he
used to connect to his car battery to start it, and then clamp them to
the frame when not in use. Although that's a dead short, the charging
circuit still works.

That's not the problem though. It's putting out 16V, which I suspect
will fry the little U1 battery. Apparently Onan used two different
charging systems on these gensets. The better one had a voltage
regulator and the specs for that say that it shouldn't go over 14 V.
The other type had a simple diode that just rectified the current and
sent it to the battery. I have the latter. I talked to a local small
engine repair person and he said 16-18 V is common with that type of
charging system and the current is so low that it doesn't hurt the
battery. What say you all about that diode system and the health of
the battery. Is it worth putting a regulator on, or is the alternator
so low powered in this type that it wouldn't make a difference? Is
there a common voltage regulator that I could stick on there that
would work better?

On 2011-02-16, GeoLane at PTD dot NET GeoLane wrote:
In my case it's an Onan genset with an Onan Elite E140H 14 HP engine.
The generator is a Pro 6000E Model EGHEB

The former owner had alligator clips on the battery cables that he
used to connect to his car battery to start it, and then clamp them to
the frame when not in use. Although that's a dead short, the charging
circuit still works.

That's not the problem though. It's putting out 16V, which I suspect
will fry the little U1 battery. Apparently Onan used two different
charging systems on these gensets. The better one had a voltage
regulator and the specs for that say that it shouldn't go over 14 V.
The other type had a simple diode that just rectified the current and
sent it to the battery. I have the latter. I talked to a local small
engine repair person and he said 16-18 V is common with that type of
charging system and the current is so low that it doesn't hurt the
battery. What say you all about that diode system and the health of
the battery. Is it worth putting a regulator on, or is the alternator
so low powered in this type that it wouldn't make a difference? Is
there a common voltage regulator that I could stick on there that
would work better?

You can run a battery charger from the AC side.

i

On Tue, 15 Feb 2011 22:53:18 -0500, GeoLane at PTD dot NET GeoLane at
PTD dot NET wrote:

In my case it's an Onan genset with an Onan Elite E140H 14 HP engine.
The generator is a Pro 6000E Model EGHEB

The former owner had alligator clips on the battery cables that he
used to connect to his car battery to start it, and then clamp them to
the frame when not in use. Although that's a dead short, the charging
circuit still works.

That's not the problem though. It's putting out 16V, which I suspect
will fry the little U1 battery. Apparently Onan used two different
charging systems on these gensets. The better one had a voltage
regulator and the specs for that say that it shouldn't go over 14 V.
The other type had a simple diode that just rectified the current and
sent it to the battery. I have the latter. I talked to a local small
engine repair person and he said 16-18 V is common with that type of
charging system and the current is so low that it doesn't hurt the
battery. What say you all about that diode system and the health of
the battery. Is it worth putting a regulator on, or is the alternator
so low powered in this type that it wouldn't make a difference? Is
there a common voltage regulator that I could stick on there that
would work better?
The one for the other onan engine should likely fit.
16 to 16 volts open circuit would not be a problem if the battery
voltage never goes over 14.4. You could always add another diode in
series to peel off another 0.7 volts

GeoLane at PTD dot NET wrote:
In my case it's an Onan genset with an Onan Elite E140H 14 HP engine.
The generator is a Pro 6000E Model EGHEB

The former owner had alligator clips on the battery cables that he
used to connect to his car battery to start it, and then clamp them to
the frame when not in use. Although that's a dead short, the charging
circuit still works.

That is a Clue!

That's not the problem though. It's putting out 16V, which I suspect
will fry the little U1 battery.

Refer to Clue above. I suspect that the charging circuit is
heavily current - limited and would not supply sufficient
current into the very low impedance of a properly sized battery
to cause harm.

I would borrow a battery from one of my fleet vehicles and
place an ammeter in series, between it and the charging
circuit. Chances are that the current reading is quite
low and that the battery voltage never would get above
a safe level.

--Winston

"Winston" wrote in message
...
GeoLane at PTD dot NET wrote:
In my case it's an Onan genset with an Onan Elite E140H 14 HP engine.
The generator is a Pro 6000E Model EGHEB

The former owner had alligator clips on the battery cables that he
used to connect to his car battery to start it, and then clamp them to
the frame when not in use. Although that's a dead short, the charging
circuit still works.

That is a Clue!

That's not the problem though. It's putting out 16V, which I suspect
will fry the little U1 battery.

Refer to Clue above. I suspect that the charging circuit is
heavily current - limited and would not supply sufficient
current into the very low impedance of a properly sized battery
to cause harm.


DC circuits have zero impedance

I would borrow a battery from one of my fleet vehicles and
place an ammeter in series, between it and the charging
circuit. Chances are that the current reading is quite
low and that the battery voltage never would get above
a safe level.

--Winston

"PrecisionmachinisT" wrote in message
news:BaSdnaIwhJfFFcbQnZ2dnUVZ_hydnZ2d@scnresearch. com...

"Winston" wrote in message
...
GeoLane at PTD dot NET wrote:
In my case it's an Onan genset with an Onan Elite E140H 14 HP engine.
The generator is a Pro 6000E Model EGHEB

The former owner had alligator clips on the battery cables that he
used to connect to his car battery to start it, and then clamp them to
the frame when not in use. Although that's a dead short, the charging
circuit still works.

That is a Clue!

That's not the problem though. It's putting out 16V, which I suspect
will fry the little U1 battery.

Refer to Clue above. I suspect that the charging circuit is
heavily current - limited and would not supply sufficient
current into the very low impedance of a properly sized battery
to cause harm.


DC circuits have zero impedance

Unfiltered DC, such as coming from a magnet passing a coil, is DC because it
never changes direction of flow, but the voltage does change, creating a
back EMF and an impedance in inductive circuits. It's DC, but alternating
DC, just like a rectifier on the output of a transformer.


I would borrow a battery from one of my fleet vehicles and
place an ammeter in series, between it and the charging
circuit. Chances are that the current reading is quite
low and that the battery voltage never would get above
a safe level.

--Winston

PrecisionmachinisT wrote:

DC circuits have zero impedance

No, they have zero _reactance_; the impedance is simply equal to
the resistance, which is the real component of impedance, which
is a complex number.

Hope This Helps!
Rich

On Wed, 16 Feb 2011 02:28:02 -0800, the renowned Rich Grise
wrote:

PrecisionmachinisT wrote:

DC circuits have zero impedance

No, they have zero _reactance_; the impedance is simply equal to
the resistance, which is the real component of impedance, which
is a complex number.

Hope This Helps!
Rich

Sooo.. you're saying a (non faulty) capacitor has zero reactance at
DC?



Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

On Feb 16, 3:18*am, "PrecisionmachinisT"
wrote:
"Winston" wrote in message
...
Refer to Clue above. *I suspect that the charging circuit is
heavily current - limited and would not supply sufficient
current into the very low impedance of a properly sized battery
to cause harm.

DC circuits have zero impedance
....

DC circuits eventually settle to voltage and current values determined
by resistance, regardless of their reactance which can be
considerable. Impedance is the combination of resistance and
reactance, as Rich wrote. For 12V lead-acids the temporary surface
charge of about a volt also affects the charging current.
http://batteryuniversity.com/learn/a...d_acid_battery

When testing the "45W" HF solar panels I found a bad Hawker Cyclone
that I hadn't been charging as the article recommends.

BTW the solar panel rating is misleading, They produced nearly their
rated current but the rated voltage to get 45W is 17.5V which they may
well reach but not when directly connected to a 12V battery as with
the included controller. I saw 32W, still not bad for February in NH.
The local store had them at $159 and I got some more off for taking a
crushed box. They tested OK for open voltage and shorted current in
the parking lot.

I bought a bunch of the cheap HF multimeters for battery and auto
work. The 10A range is good enough to check small-engine charging
currents and if I fry one I'm out only $3 - $5. I checked two against
good lab voltmeters last night and found they were about 5 counts off,
50mV at 10V, which doesn't really matter for 12V lead-acids.

jsw

Spehro Pefhany wrote:
On Wed, 16 Feb 2011 02:28:02 -0800, the renowned Rich Grise
PrecisionmachinisT wrote:

DC circuits have zero impedance

No, they have zero _reactance_; the impedance is simply equal to
the resistance, which is the real component of impedance, which
is a complex number.

Sooo.. you're saying a (non faulty) capacitor has zero reactance at
DC?

Of course not, you nincompoop. A capacitor is an open circuit at DC,
so the concept of impedance is meaningless.

Hope This Helps!
Rich

On Tue, 15 Feb 2011 22:53:18 -0500, GeoLane at PTD dot NET GeoLane at
PTD dot NET wrote:

In my case it's an Onan genset with an Onan Elite E140H 14 HP engine.
The generator is a Pro 6000E Model EGHEB

The former owner had alligator clips on the battery cables that he
used to connect to his car battery to start it, and then clamp them to
the frame when not in use. Although that's a dead short, the charging
circuit still works.

That's not the problem though. It's putting out 16V, which I suspect
will fry the little U1 battery. Apparently Onan used two different
charging systems on these gensets. The better one had a voltage
regulator and the specs for that say that it shouldn't go over 14 V.
The other type had a simple diode that just rectified the current and
sent it to the battery. I have the latter. I talked to a local small
engine repair person and he said 16-18 V is common with that type of
charging system and the current is so low that it doesn't hurt the
battery. What say you all about that diode system and the health of
the battery. Is it worth putting a regulator on, or is the alternator
so low powered in this type that it wouldn't make a difference? Is
there a common voltage regulator that I could stick on there that
would work better?

Rectifying the output of a small engine's alternator and feeding
straight to the battery is very common. Nearly all of the smaller
Japanese motorcycles are made that way, sometimes with the addition of
a switchable resister, wired through the light switch, so that
alternator output is reduced a bit for running without the lights.

What I'd is to fire things up and check the voltage at the battery
terminals, if the actual battery voltage doesn't get over about 14
volts then I wouldn't worry about it. My guess is that you'll be
getting closer to 14 volts with the engine running.

On Wed, 16 Feb 2011 05:02:41 -0800, the renowned Rich Grise
wrote:

Spehro Pefhany wrote:
On Wed, 16 Feb 2011 02:28:02 -0800, the renowned Rich Grise
PrecisionmachinisT wrote:

DC circuits have zero impedance

No, they have zero _reactance_; the impedance is simply equal to
the resistance, which is the real component of impedance, which
is a complex number.

Sooo.. you're saying a (non faulty) capacitor has zero reactance at
DC?

Of course not, you nincompoop. A capacitor is an open circuit at DC,
so the concept of impedance is meaningless.

Actually, the _susceptance_ approaches zero as f-0
(susceptance is 1/reactance),

The reactance of an inductor approaches zero as f-0
(susceptance heads for the roof)

Hope This Helps!
Rich

Immensely, Rich. WTF are you doing up at 5AM CA time anyway?


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

Jim Wilkins wrote:
On Feb 16, 3:18 am, "PrecisionmachinisT"
wrote:
wrote in message
...
Refer to Clue above. I suspect that the charging circuit is
heavily current - limited and would not supply sufficient
current into the very low impedance of a properly sized battery
to cause harm.

DC circuits have zero impedance
....

DC circuits eventually settle to voltage and current values determined
by resistance, regardless of their reactance which can be
considerable. Impedance is the combination of resistance and
reactance, as Rich wrote.

Right, but this isn't a 'pure' DC circuit.

By mentioning 'impedance' instead of just ESR, I hoped to remind us
that the current waveform into the battery is dependent on
it's Equivalent Series Resistance *as well as* how it 'looks'
to the pulses of D.C. from the rectifier, in the frequency domain.

See for example, Table 1 of:
http://www.telepower.com.au/INT95b.PDF

Here is a gross example to show the effect.

If you load the following circuit into LTSpice, you can vary
the inductance of L1 to change the inductive reactance seen by
the generator winding. (The circuit shows the output of the
'battery charge' winding in series with a rectifier, a 1.0 mH
inductor and a battery that has an ESR set to 1.2 milliohm.
The generator is running at 3600 RPM).

Note that I am *not* saying that the inductive reactance of
any healthy battery is *anywhere* near as high as shown in
this circuit. I'm just showing that pulsed D.C. faces more
'opposition to flow' than that posed by simple resistance.

Even with the D.C. resistance of the inductor fixed at zero, the
peak current into the battery will be inversely proportional to
the inductance of L1 (in addition to the ESR of the battery and
the effect of the forward drop of the rectifier).


Version 4
SHEET 1 1276 680
WIRE 32 144 -64 144
WIRE 224 144 96 144
WIRE 336 144 304 144
WIRE 336 192 336 144
WIRE -64 256 -64 144
WIRE 336 304 336 272
WIRE -64 368 -64 336
FLAG 336 304 0
FLAG -64 368 0
SYMBOL voltage -64 240 R0
WINDOW 3 13 107 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR Value SINE(0 22.6 60 0 0 0 5)
SYMATTR InstName V1
SYMBOL voltage 336 176 R0
WINDOW 123 0 0 Left 0
WINDOW 39 24 132 Left 0
SYMATTR InstName V2
SYMATTR Value 12
SYMATTR SpiceLine Rser=1.2m
SYMBOL ind 208 160 R270
WINDOW 0 32 56 VTop 0
WINDOW 3 5 56 VBottom 0
SYMATTR InstName L1
SYMATTR Value 1m
SYMATTR SpiceLine Rser=0
SYMBOL diode 32 160 R270
WINDOW 0 32 32 VTop 0
WINDOW 3 0 32 VBottom 0
SYMATTR InstName D1
TEXT -80 416 Left 0 !.tran 0 .1 0

--Winston 'Z is the word is the word is the word..'

On Feb 16, 10:38*am, Winston wrote:
Jim Wilkins wrote:
On Feb 16, 3:18 am, "PrecisionmachinisT"
*wrote:
*wrote in message
...

Right, but this isn't a 'pure' DC circuit.

By mentioning 'impedance' instead of just ESR, I hoped to remind us
that the current waveform into the battery is dependent on
it's Equivalent Series Resistance *as well as* how it 'looks'
to the pulses of D.C. from the rectifier, in the frequency domain.

See for example, Table 1 of:http://www.telepower.com.au/INT95b.PDF

Interesting.

The test I've seen and done for battery impedance is to measure the
voltage at a steady low-level current, then pulse on a higher load and
capture the voltage and current waveforms on a digital storage scope.
The impedance is the slope of the line between the low and high
current V and I, at a place on the waveform chosen by the battery
engineer. The higher frequency effects which are relevant to PWM motor
drivers are easily removed with capacitors. The low frequency
impedance (mostly resistance) is a good measure of the condition of
the battery.

jsw

Jim Wilkins wrote:
On Feb 16, 10:38 am, wrote:

(...)

Right, but this isn't a 'pure' DC circuit.

By mentioning 'impedance' instead of just ESR, I hoped to remind us
that the current waveform into the battery is dependent on
it's Equivalent Series Resistance *as well as* how it 'looks'
to the pulses of D.C. from the rectifier, in the frequency domain.

See for example, Table 1 of:http://www.telepower.com.au/INT95b.PDF

Interesting.

The test I've seen and done for battery impedance is to measure the
voltage at a steady low-level current, then pulse on a higher load and
capture the voltage and current waveforms on a digital storage scope.
The impedance is the slope of the line between the low and high
current V and I, at a place on the waveform chosen by the battery
engineer.

Note how Hawkins and Barling used a one-step process
for each frequency of interest with their very low impedance
measuring circuit.

http://www.telepower.com.au/INT95b.PDF
By forcing a small, levelled, alternating broadband current
through the battery, they measured the resulting voltage
between 5 milli-Hz to 100 Hz in order to arrive at an
impedance reading, calculated by an attached PC.
They went on to measure impedance above 10 Hz (to 100 KHz)
using current-levelled sinewave excitation.

Impedance scaled directly with the voltage - to - current
ratio at any given frequency. Because current was known and
held constant, Z was directly proportional to V. Kewl!

The higher frequency effects which are relevant to PWM motor
drivers are easily removed with capacitors.

The low frequency impedance (mostly resistance) is a good
measure of the condition of the battery.

Abso-tively.

--Winston

Spehro Pefhany wrote:
On Wed, 16 Feb 2011 05:02:41 -0800, the renowned Rich Grise
Spehro Pefhany wrote:
On Wed, 16 Feb 2011 02:28:02 -0800, the renowned Rich Grise
PrecisionmachinisT wrote:

DC circuits have zero impedance

No, they have zero _reactance_; the impedance is simply equal to
the resistance, which is the real component of impedance, which
is a complex number.

Sooo.. you're saying a (non faulty) capacitor has zero reactance at
DC?

Of course not, you nincompoop. A capacitor is an open circuit at DC,
so the concept of impedance is meaningless.

Actually, the _susceptance_ approaches zero as f-0
(susceptance is 1/reactance),

The reactance of an inductor approaches zero as f-0
(susceptance heads for the roof)

Hope This Helps!
Rich

Immensely, Rich. WTF are you doing up at 5AM CA time anyway?

There's no real work for me (I do autocad and geek stuff), so I get
to sweep the floors and take out the trash and clean the sinks and
toilets, and in exchange they let me sleep in the office rent-free
and eat donated food. (I got evicted when I went broke and couldn't
pay the rent.)

Occasionally I get some real work, but the company can't afford to
pay me money until about next April; they're behind on the rent as
well, but the landlord is a freakin' angel or something. :-)

Cheers!
Rich

Jim Wilkins wrote:

I bought a bunch of the cheap HF multimeters for battery and auto
work. The 10A range is good enough to check small-engine charging
currents and if I fry one I'm out only $3 - $5. I checked two against
good lab voltmeters last night and found they were about 5 counts off,
50mV at 10V, which doesn't really matter for 12V lead-acids.

Well, lessee - 0.050 / 10 is, what, a half a percent? That's pretty
good for a three dollar meter! ;-)

Cheers!
Rich

On Feb 16, 4:52*pm, Winston wrote:
Jim Wilkins wrote:
...
Note how Hawkins and Barling used a one-step process
for each frequency of interest with their very low impedance
measuring circuit.

http://www.telepower.com.au/INT95b.PDF
By forcing a small, levelled, alternating broadband current
through the battery, they measured the resulting voltage
between 5 milli-Hz to *100 Hz in order to arrive at an
impedance reading, calculated by an attached PC.
They went on to measure impedance above 10 Hz (to 100 KHz)
using current-levelled sinewave excitation.
..
--Winston-

Did it seem to you that they might have been measuring the response of
their test setup in addition to the batteries?

jsw

On Feb 16, 5:07*pm, Rich Grise wrote:
Jim Wilkins wrote:

I bought a bunch of the cheap HF multimeters for battery and auto
work. The 10A range is good enough to check small-engine charging
currents and if I fry one I'm out only $3 - $5. I checked two against
good lab voltmeters last night and found they were about 5 counts off,
50mV at 10V, which doesn't really matter for 12V lead-acids.

Well, lessee - 0.050 / 10 is, what, a half a percent? That's pretty
good for a three dollar meter! ;-)

Cheers!
Rich

The Keithley and Fluke agree to +-1mV. Their last calibrations were in
1994 and 95.

jsw

Jim Wilkins wrote:
On Feb 16, 5:07*pm, Rich Grise wrote:
Jim Wilkins wrote:

I bought a bunch of the cheap HF multimeters for battery and auto
work. The 10A range is good enough to check small-engine charging
currents and if I fry one I'm out only $3 - $5. I checked two against
good lab voltmeters last night and found they were about 5 counts off,
50mV at 10V, which doesn't really matter for 12V lead-acids.

Well, lessee - 0.050 / 10 is, what, a half a percent? That's pretty
good for a three dollar meter! ;-)

The Keithley and Fluke agree to +-1mV. Their last calibrations were in
1994 and 95.

Oh, of course, no question! But you're not going to get a Keithley or
Fluke at Harbor Freight for three bucks! ;-)

Cheers!
Rich

Jim Wilkins wrote:
On Feb 16, 4:52 pm, wrote:
Jim Wilkins wrote:
...
Note how Hawkins and Barling used a one-step process
for each frequency of interest with their very low impedance
measuring circuit.

http://www.telepower.com.au/INT95b.PDF
By forcing a small, levelled, alternating broadband current
through the battery, they measured the resulting voltage
between 5 milli-Hz to 100 Hz in order to arrive at an
impedance reading, calculated by an attached PC.
They went on to measure impedance above 10 Hz (to 100 KHz)
using current-levelled sinewave excitation.
..
--Winston-

Did it seem to you that they might have been measuring the response of
their test setup in addition to the batteries?

No doubt they did.

One can only hope that they minimised noise of various kinds,
virtually eliminated coloration of the data by their test
set and did a few sanity checks before publishing data.

The good news is that they *could* use various capacitors
and inductors as transfer standards, measured with a
calibrated bridge to get an idea of where inaccuracies
might lay.

--Winston --"LISN, do you want to know a secret?"

From what I've been able to find/determine about some of the newer hand-held
battery analyzers (approx $300 price range), this method of applying a small
load and then pulsing the battery is how the displayed results are
calculated.. allowing a thorough test to be performed by a small instrument.

I've had capacitor ESR meters for years, but they're generally not reliable
for battery testing, and some designs just won't tolerate an input voltage
at the test input.
Many cap ESR testers' operating frequencies range from 1k to 100k (single
frequency, not variable or selectable) possibly with the majority of testers
utilizing 1k to 10kHz.

I bought an inexpensive dedicated (1kHz) digital battery impedance meter a
while ago, speculating that it's measurement capabilities would (be useful)
help determine the matching/reliability? of individual rechargeable cells..
and possibly the condition of health of lead/acid batteries, but I haven't
investigated the meter's practicality as far as LA/car batteries after
seeing that the meter's readings were essentially only comparison readings.

From what I think I understand about similar testers (capacitance value,
ESR, current leakage etc) they're essentially AC voltmeters, and the lower
cost/non-microprocessor types generally use an IC for dual slope
integration? to establish a reading from an internal/predetermined
sample/component.
It seems that the meter's usefullness would mostly be of use for comparing
readings of nearly identical cell/battery types, but otherwise just a tool
to gather readings which could be useful for statistical data (which may or
may not be useful after many entries).

--
WB
..........


"Jim Wilkins" wrote in message
...

Interesting.

The test I've seen and done for battery impedance is to measure the
voltage at a steady low-level current, then pulse on a higher load and
capture the voltage and current waveforms on a digital storage scope.
The impedance is the slope of the line between the low and high
current V and I, at a place on the waveform chosen by the battery
engineer. The higher frequency effects which are relevant to PWM motor
drivers are easily removed with capacitors. The low frequency
impedance (mostly resistance) is a good measure of the condition of
the battery.

jsw

On Feb 16, 6:32*pm, "Wild_Bill" wrote:
...
It seems that the meter's usefullness would mostly be of use for comparing
readings of nearly identical cell/battery types, but otherwise just a tool
to gather readings which could be useful for statistical data (which may or
may not be useful after many entries).
WB

It might be good if you buy second-hand batteries replaced on a
schedule. To test and accept/reject new ones you'd need the battery
manufacturer's spec sheet.

I measure a battery's remaining capacity as how long it will run this
laptop. When the screen brightness changes the inverter has just shut
down.

jsw

On Feb 16, 5:51*pm, Winston wrote:
Jim Wilkins wrote:
On Feb 16, 4:52 pm, *wrote:
Jim Wilkins wrote:
...
Note how Hawkins and Barling used a one-step process
for each frequency of interest with their very low impedance
measuring circuit.

http://www.telepower.com.au/INT95b.PDF
.....
--Winston-

Did it seem to you that they might have been measuring the response of
their test setup in addition to the batteries?

No doubt they did.

One can only hope that they minimised noise of various kinds,
virtually eliminated coloration of the data by their test
set and did a few sanity checks before publishing data.

The good news is that they *could* use various capacitors
and inductors as transfer standards, measured with a
calibrated bridge to get an idea of where inaccuracies
might lay.

--Winston

They didn't even bother to draw a Kelvin connection for the voltmeter.
In my experience engineers who know they need one make sure to show
it.

jsw

Yep.. and the issue of buying used batteries (for rejuvenation by
desulphator) for off-grid power was where I first encountered the use of
"testing battery internal resistance", years ago.

One example I forgot to mention which may prove worthwhile for using a
battery impedance meter, would be routinely checking SLA batteries for large
UPS batteries, if the batteries are of similar capacities/models, and most
from the same manufacturer.
Fleet vehicle maintenance personnel may also find these meters helpful when
used periodically.

Specific battery specs are becoming more readily available more recently..
perhaps just to appease potential buyers, moreso than actually being
factual.

I feel the way you do about battery *packs*.. their worthiness will become
evident in real-world use. I generally put stickers on rechargeable packs
for noting dates and charging durations.
I thought that one good use for the battery impedance meter would be to help
match cells for pack building.. and maybe it would be after some rather
extensive testing experience (hundreds of cells).

Although I have several battery load testers (and hydrometers) for large LA
batteries.. load testing can be very useful, but not very scientific without
a precise timer and/or other means of plotting the battery's output during
the test (also temperature).
Overall, I'd say load testing is a reliable good/bad test (no large grey
area) when checking high capacity (automotive sized) batteries.

--
WB
..........


"Jim Wilkins" wrote in message
...
On Feb 16, 6:32 pm, "Wild_Bill" wrote:
...
It seems that the meter's usefullness would mostly be of use for comparing
readings of nearly identical cell/battery types, but otherwise just a tool
to gather readings which could be useful for statistical data (which may
or
may not be useful after many entries).
WB

It might be good if you buy second-hand batteries replaced on a
schedule. To test and accept/reject new ones you'd need the battery
manufacturer's spec sheet.

I measure a battery's remaining capacity as how long it will run this
laptop. When the screen brightness changes the inverter has just shut
down.

jsw

Jim Wilkins wrote:

(...)

They didn't even bother to draw a Kelvin connection for the voltmeter.
In my experience engineers who know they need one make sure to show
it.

I suspect that is a documentation problem rather than an
engineering problem. Their data are strewn with sub-milliohm
impedance readings that would be just about impossible to
get without a Kelvin connection.

Communication can be challenging.

Perhaps you have experienced the frustration of seeing the
final product of your efforts irreparably damaged because
someone higher in the food chain couldn't keep their
grubby hands off your source code?

--Winston -- That was in 1996. (I'm better now.)

On Tue, 15 Feb 2011 22:04:10 -0600, Ignoramus20463
wrote:



That's not the problem though. It's putting out 16V, which I suspect
will fry the little U1 battery.


You can run a battery charger from the AC side.


I could, but the owners manual says not to run the generator without a
battery connected. I don't know if the previous owner damaged the
system by doing that. I suspect that it didn't or I wouldn't be
seeing any voltage being sent to the battery to charge it.

RWL

On Tue, 15 Feb 2011 22:53:18 -0500, GeoLane at PTD dot NET GeoLane at
PTD dot NET wrote:

That's not the problem though. It's putting out 16V, which I suspect
will fry the little U1 battery.


On Wed, 16 Feb 2011 20:16:20 +0700, john B.
wrote:

Rectifying the output of a small engine's alternator and feeding
straight to the battery is very common. Nearly all of the smaller
Japanese motorcycles are made that way,

What I'd is to fire things up and check the voltage at the battery
terminals, if the actual battery voltage doesn't get over about 14
volts then I wouldn't worry about it. My guess is that you'll be
getting closer to 14 volts with the engine running.

It's feeding 16V to the battery when it's running and the battery is
connected.

How many amps might I anticipate being sent to the battery? I didn't
have much success measuring the amps last evening, but I may have time
to try that again over the weekend. I don't want to fry my VOM. I
had tried on the 10A setting and didn't get a reading. I dropped to
the next lowest range - 500 mA, but still didn't get a reading.

RWL

On Wed, 16 Feb 2011 23:15:01 -0500, GeoLane at PTD dot NET wrote:
On Tue, 15 Feb 2011 22:53:18 -0500, GeoLane at PTD dot NET wrote:
That's not the problem though. It's putting out 16V, which I suspect
will fry the little U1 battery.

On Wed, 16 Feb 2011 20:16:20 +0700, john B. Slocomb wrote:

Rectifying the output of a small engine's alternator and feeding
straight to the battery is very common. Nearly all of the smaller
Japanese motorcycles are made that way,

What I'd is to fire things up and check the voltage at the battery
terminals, if the actual battery voltage doesn't get over about 14 volts
then I wouldn't worry about it. My guess is that you'll be getting
closer to 14 volts with the engine running.

It's feeding 16V to the battery when it's running and the battery is
connected.

How many amps might I anticipate being sent to the battery? I didn't
have much success measuring the amps last evening, but I may have time
to try that again over the weekend. I don't want to fry my VOM. I had
tried on the 10A setting and didn't get a reading. I dropped to the
next lowest range - 500 mA, but still didn't get a reading.

With current that low, you can put a 1, 10, or 100 ohm resistor
in series to measure voltage drop, and calculate current. For
example, if you measure 0.5 volts across a 100 ohm resistor,
I = E/R = .5/100 = 5 mA.

If you are measuring 16V DC across a 12V lead-acid battery at low
current, something is wrong with the measurement or the battery.
Do you have an oscilloscope? Maybe your voltmeter is measuring
peak voltage of spikes, although that's not something I would
expect if you are actually using a mechanical-meter-movement
VOM rather than a DVM, and are measuring on a DC volts range.

--
jiw

GeoLane at PTD dot NET wrote:

(...)

It's feeding 16V to the battery when it's running and the battery is
connected.

(...)

I dropped to
the next lowest range - 500 mA, but still didn't get a reading.

Taking those two symptoms at face value, I'd say that at
least one of the cells in your battery has opened up
and the battery is no longer 'fit for service'.

I wonder what voltage reading you would get with a
'tested good' car battery?

--Winston

On Feb 17, 12:08*am, Steve Ackman
wrote:
In , on
Wed, 16 Feb 2011 04:54:57 -0800 (PST), Jim Wilkins, wrote:

I saw 32W, still not bad for February in NH.
The local store had them at $159 and I got some more off for taking a
crushed box.

* You've piqued my curiosity. *Since when has there
been a Harbor Freight in NH?

It opened in December. It's on Rt 101A in Amherst between Nashua and
Milford, across from Lowe's near the Wal-Mart.

You know where Circuit City used to be? (Traditional NH directions to
snag unwelcome refugees from MA)

One clerk told me they stock only about 30% of what's in the catalog,
but it's a big store with a good selection.

jsw

On Wed, 16 Feb 2011 23:15:01 -0500, GeoLane at PTD dot NET GeoLane at
PTD dot NET wrote:


On Tue, 15 Feb 2011 22:53:18 -0500, GeoLane at PTD dot NET GeoLane at
PTD dot NET wrote:

That's not the problem though. It's putting out 16V, which I suspect
will fry the little U1 battery.


On Wed, 16 Feb 2011 20:16:20 +0700, john B.
wrote:

Rectifying the output of a small engine's alternator and feeding
straight to the battery is very common. Nearly all of the smaller
Japanese motorcycles are made that way,

What I'd is to fire things up and check the voltage at the battery
terminals, if the actual battery voltage doesn't get over about 14
volts then I wouldn't worry about it. My guess is that you'll be
getting closer to 14 volts with the engine running.

It's feeding 16V to the battery when it's running and the battery is
connected.

How many amps might I anticipate being sent to the battery? I didn't
have much success measuring the amps last evening, but I may have time
to try that again over the weekend. I don't want to fry my VOM. I
had tried on the 10A setting and didn't get a reading. I dropped to
the next lowest range - 500 mA, but still didn't get a reading.

RWL

You mean that with the engine running you measure the voltage across
the battery and it reads 16 volts?

I would be very leery of checking amperage with a multimeter. they
usually have almost insignificant ranges for cars n stuff.

But you don't really need to know the amperage as the voltage will
tell you all you need to know. Your maximum charging voltage should be
about 14.1 - 14.2 for a 12 volt battery. If you hold the voltage to
that level the amperage will be safe.

On Feb 15, 10:53*pm, GeoLane at PTD dot NET GeoLane at PTD dot NET
wrote:
...
That's not the problem though. *It's putting out 16V, which I suspect
will fry the little U1 battery. *

Too late, that's a symptom of one or more bad cells. Sometimes they
can be partly restored by forcing current through them at a higher
voltage like 18 - 20V if you have a lab power supply or home-made
adjustable charger.

The battery that came with my Sears garden tractor was dead (like much
of the machine) but took a few milliamps at ~18V, then the current
slowly increased until after a day it charged normally. I got 4 more
years from it until the 12V winch ruined it, then I put in a WalMart
battery that died irreversibly in one year. Now it has one from
BatteriesPlus that has survived two winters at least.

jsw

You might try taking a current measurement with a small lamp of a known
operating current (the current can easily be looked up online, by the lamp
number).

This way, you can determine that the meter will give a reading in the
appropriate ranges, of close-to published specs.

--
WB
..........


GeoLane at PTD dot NET wrote in message
...

It's feeding 16V to the battery when it's running and the battery is
connected.

How many amps might I anticipate being sent to the battery? I didn't
have much success measuring the amps last evening, but I may have time
to try that again over the weekend. I don't want to fry my VOM. I
had tried on the 10A setting and didn't get a reading. I dropped to
the next lowest range - 500 mA, but still didn't get a reading.

RWL

On Feb 17, 9:40*am, "Wild_Bill" wrote:
You might try taking a current measurement with a small lamp of a known
operating current (the current can easily be looked up online, by the lamp
number).

This way, you can determine that the meter will give a reading in the
appropriate ranges, of close-to published specs.

--
WB
.........
It's feeding 16V to the battery when it's running and the battery is
connected.

Or put the lamp across the battery without touching the charging leads
and see if the current increases, proving all your connections are
good.

jsw

On Wed, 16 Feb 2011 23:15:01 -0500, GeoLane at PTD dot NET GeoLane at
PTD dot NET wrote:


On Tue, 15 Feb 2011 22:53:18 -0500, GeoLane at PTD dot NET GeoLane at
PTD dot NET wrote:

That's not the problem though. It's putting out 16V, which I suspect
will fry the little U1 battery.


On Wed, 16 Feb 2011 20:16:20 +0700, john B.
wrote:

Rectifying the output of a small engine's alternator and feeding
straight to the battery is very common. Nearly all of the smaller
Japanese motorcycles are made that way,

What I'd is to fire things up and check the voltage at the battery
terminals, if the actual battery voltage doesn't get over about 14
volts then I wouldn't worry about it. My guess is that you'll be
getting closer to 14 volts with the engine running.

It's feeding 16V to the battery when it's running and the battery is
connected.

How many amps might I anticipate being sent to the battery? I didn't
have much success measuring the amps last evening, but I may have time
to try that again over the weekend. I don't want to fry my VOM. I
had tried on the 10A setting and didn't get a reading. I dropped to
the next lowest range - 500 mA, but still didn't get a reading.

RWL

I suspect your battery is "pooched"? (or fully charged - either will
draw no current and allow high voltage) Most are 1.5 to 3 amp.

On Thu, 17 Feb 2011 19:55:24 +0700, john B.
wrote:

On Wed, 16 Feb 2011 23:15:01 -0500, GeoLane at PTD dot NET GeoLane at
PTD dot NET wrote:


On Tue, 15 Feb 2011 22:53:18 -0500, GeoLane at PTD dot NET GeoLane at
PTD dot NET wrote:

That's not the problem though. It's putting out 16V, which I suspect
will fry the little U1 battery.


On Wed, 16 Feb 2011 20:16:20 +0700, john B.
wrote:

Rectifying the output of a small engine's alternator and feeding
straight to the battery is very common. Nearly all of the smaller
Japanese motorcycles are made that way,

What I'd is to fire things up and check the voltage at the battery
terminals, if the actual battery voltage doesn't get over about 14
volts then I wouldn't worry about it. My guess is that you'll be
getting closer to 14 volts with the engine running.

It's feeding 16V to the battery when it's running and the battery is
connected.

How many amps might I anticipate being sent to the battery? I didn't
have much success measuring the amps last evening, but I may have time
to try that again over the weekend. I don't want to fry my VOM. I
had tried on the 10A setting and didn't get a reading. I dropped to
the next lowest range - 500 mA, but still didn't get a reading.

RWL

You mean that with the engine running you measure the voltage across
the battery and it reads 16 volts?

I would be very leery of checking amperage with a multimeter. they
usually have almost insignificant ranges for cars n stuff.

But you don't really need to know the amperage as the voltage will
tell you all you need to know. Your maximum charging voltage should be
about 14.1 - 14.2 for a 12 volt battery. If you hold the voltage to
that level the amperage will be safe.
And if the battery is no good, the voltage WILL go higher on a
resistance regulated system (which is basically what he has)

Jim Wilkins wrote:
Steve Ackman wrote:
....
You've piqued my curiosity. Since when has there
been a Harbor Freight in NH?

It opened in December. It's on Rt 101A in Amherst between Nashua and
Milford, across from Lowe's near the Wal-Mart.
...

And ... do you know that there is now another one in MA? In Danvers, on
Rt 1. I've been meaning to visit, but haven't yet. Bob

On Feb 17, 6:30*pm, Steve Ackman
wrote:
Thu, 17 Feb 2011 04:20:59 -0800 (PST), Jim Wilkins, wrote:
On Feb 17, 12:08*am, Steve Ackman
wrote:
* You've piqued my curiosity. *Since when has there
been a Harbor Freight in NH?

[southern NH]
* Ah... a part of the state I never went to even
when I lived there.

Definitely not a tourist attraction.

* No. *I don't even know where Nashua, NH used to be.
I think it's officially part of North Massachussetts
now, isn't it?

When I lived in Concord I felt that way too, but it's much closer to
the high-tech jobs. The surrounding towns are still NH, town meetings,
pickup trucks and wood smoke. The cities of northern Mass are part of
neither state, they're in the Third World.

One clerk told me they stock only about 30% of what's in the catalog,
but it's a big store with a good selection.

I *might* do it for something big, like a milling
machine, lathe, etc. just to get eyes-on before opening
the wallet.

That's part of the 70% they don't stock. They have only a mini lathe
and a few of the unpowered machines like benders.

jsw

"PrecisionmachinisT" writes:



DC circuits have zero impedance

Oh? Wish they told me that early on in my EE courses; I could
saved a LOT of homework...

--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433