Battery SG 1.295? Is that even possible???

[RDMueller]

...or have I just bought another useless hydrometer that should be tossed along with the one with the 4 floating balls and the EZ-Red?

It is a Hydro Volt and after reading about it, I thought it just might be the "better mouse trap." It is very easy to use and very easy to read, but if it's not accurate down to at least .002 or so, then I don't see the point.

All 6 cells of my two fully charged T105s read 1.295 +/- .001 even though 1.277 should be 100%. I've gone thru this before with other things, my DMM for example. I had one that I've used for years that I started to become suspicious of because it disagreed with the voltage display on my Powermax and the ammeter/voltmeter I had connected to it. Bought a new DMM and what do you know, a 0.3V difference!

I'll just say this, I HATE instruments that are not properly calibrated! Just so frustrating :M

[SCVJeff]

Like I said, once in awhile a better mouse trap comes along. The other complaint I now have against a bobber is that tonight the battery in the Honda went TU. The way the internals are designed I couldn't draw enough liquid to float the bobber, where the HydroVolt had no issues whatsoever with the little fluid I could pull.

[CJW8]

I got a chance to use my hydra volt today. It agreed precisely with my tried and true bobber. All cells on 3 Grp 24's were 1.275 with a couple at 1.265.
My work truck has been cranking slow lately so I decided to check it. It is a maintenance free battery so the caps were difficult to pry off. It has been sitting for a day and the voltage was 11.99. The indicator shows RED on the battery indication bad. All cells 1232 in the 1.165 range. Time for the company to buy me a new battery.

One thing I like about the hydra volt it it doesn't have to be held level in order to read it as long as the chamber is full. Since it is plastic and not glass there is less worry about breakage.

[pnichols]

Mex wrote:
But until gravity fails or the laws of physics are repealed, the bobber hydrometer can not be improved on - it is, stake-your-life-on-it-accurate to the ultimate degree (as long as it's a Freas).

David ... Google some geophysics articles re the Earth's gravitational field. It does vary, depending upon the location where one might be trying to check the SOS of a liquid acid battery.

But as you say, getting away from liquid entirely is the name of the game. 🙂

[MEXICOWANDERER]

Great post SoundGuy!

For most the beeg problem is finding a reliable reference voltage in the first place. I shed a tear because my Tektronix is due to be sent back for a 140 dollar calibration + postage and insurance both ways. But it's in Michoacan and I'm here in B.C.S.

There is NOTHING on the face of the earth more reliable than a calibrated bobber. The Swiss gizmo would be OK when checked against a Freas once in awhile. Parts that move, meter shafts, seals, yadda, are not bulletproof. But until gravity fails or the laws of physics are repealed, the bobber hydrometer can not be improved on - it is, stake-your-life-on-it-accurate to the ultimate degree (as long as it's a Freas).

If motorhome idiot designers make checking gravity a nightmare, graduate to AGM. It's that simple. Almost as simple as the minds that created the battery issue. If a developer ever built a house as careless and stupid as some of these new rigs, they leave themselves to have their skin removed in thin strips.

[SoundGuy]

pnichols wrote:
I recently opened my DMM and "re-calibrated" it so that it's voltage ranges now read about the same as two other voltmeters that already agreed pretty closely with each other.

Now I have 3 ways to measure RV DC voltages that are all accurate or that are all inaccurate ... depending upon whether or not one believes that 2 out of 3 must be right. 😉

I recently purchased a reasonably good quality consumer DMM and must have picked well as it reads about as close to a calibrated Fluke as one could reasonably expect considering it's price point. Interestingly my P3 Kill-a-Watt meter matches it quite closely but pretty well everything else I own doesn't, including my Progressive Industries EMS-HW30C surge protector which was calibrated to read ~ 1.4 volts high. Since the Progressive hard wire modes are user serviceable I recalibrated it so it now matches the DMM quite closely, a bit of a challenge since it only reads to the nearest volt. When I peeled back a label on an inexpensive energy meter that read several volts lower than the DM I found a calibration screw and was able to also reset it to closely match. Unfortunately the reality is that when buying consumer grade meters like this you're going to get what you get and shouldn't be surprised that calibration isn't anywhere near close as may be claimed, the good news being that in many cases you can do your own calibration provided you have one device of known correct calibration.

[SCVJeff]

(some of) You have never seen or held a HydroVolt, let alone used it. I have, and like I said, depending on how you choose to read the friction prone liquid wicking bobber, it tracks the HydroVolt nicely but the fun of deciding where and how to read the bobber is gone. I hated my bobber in the salt tank, and I hate this one the same. There are plenty of better mouse traps these days to replace a 100year old glass bobber, and this is one of them.

BTW- It's made in Switzerland

[CJW8]

Well, I bought one too. I haven't used it yet. I will this weekend when I do planned battery maintenance.

For the sake of argument, they are made in Germany and not China.

[pnichols]

I recently opened my DMM and "re-calibrated" it so that it's voltage ranges now read about the same as two other voltmeters that already agreed pretty closely with each other.

Now I have 3 ways to measure RV DC voltages that are all accurate or that are all inaccurate ... depending upon whether or not one believes that 2 out of 3 must be right. 😉

[MEXICOWANDERER]

"Muh clock sez itz 3709 Ayem. Gonna put the clock away 'till the sun don't rise. That'll fixxem"

'Bout four years ago I predicted Herb Tarlek had nowhere left to run except increase acid density and shorten warraties. Both have come to pass. Are you surprised?

A hydrometer is a tool. It is useless unless it is accurate and in the hands of an educated adult. No flooded battery uses 1.400 density electrolyte. Or is this going to turn into an Abbot & Costello routine? No you cannot suck acid out of an absorbed glass mat.

The hydrometer is garbage. Get over it. Half of you have metering and instruments that would make an osciloscope gag. If a person utlizes a hydrometer to do meaningful things get a real one.

[RDMueller]

smkettner wrote:

RDMueller wrote:
All 6 cells of my two fully charged T105s read 1.295 +/- .001 even though 1.277 should be 100%.

The battery is fine. Put the hydrometer away until you suspect an actual issue.

I agree that the batteries are fine. (They better be, they're only six months old!) I'm just trying to find out if I can trust my latest hydrometer. I already found out I had a DMM I couldn't trust, but did for many years.

As far as hydrometers, I'm on my 4th:
1. Floating balls piece of junk;
2. EZ Red, better but couldn't get a consistent reading;
3. Traditional glass hydrometer, better still but I found it hard to read plus I broke the thermometer;
4. Hydro volt, easy to use and seems consistent, just concerned it is reading high.

I'll probably just spend the money for a Freas and be done. Funny thing is, from a $ standpoint, at this point I could have just spent the extra for a pair of AGMs and been equal. :S

[time2roll]

RDMueller wrote:
All 6 cells of my two fully charged T105s read 1.295 +/- .001 even though 1.277 should be 100%.

The battery is fine. Put the hydrometer away until you suspect an actual issue.

[MrWizard]

Oh Darn

i have a hydrometer, but i never looked for the low point on the scale

[RDMueller]

MrWizard wrote:
isn't the SG of distilled water 1.0
can't the calibration be checked that way
i know the scalle could be wrong, or the weights
but zero point 1.0 sg... isn't that the SG of distilled water

True, but the scale doesn't go that low. The low end is 1.110 on the Hydro volt.

[MEXICOWANDERER]

A calibration unit IS a Freas unit. NIST qualified. I had one meaning a single refractometer back in '91 It dropped out of my pocket and down 4' onto concrete. Sudden lack of interest in refractometers. I make PVC tube holsters for Freas units. Try a series run of 24-cells like I do with my batteries. A sudden realization will dawn....