Specific gravity test special tool

[Mobilesport]

Where I work the maintenance guy has a special hose setup on the fork lift batteries so he just plug the hose in and fill with water very easily ,, got me thinking is there a special tool I can install on my battery to take a specific gravity test of a single cell , I already tested all cells and they where pretty much the same so I figured If I could test one cell everyday to know my state of charge , I was thinking of a way to just leave the hydrometer attached to a battery in just one of its cells .
Or should I get a battery monitor?

 

[ccbreder]

get a battery monitor. hydrometers can not do what you want them to do.

 

[jimindenver]

One of the values of doing the test is to see if all of the cells are the same. Finding one off can mean the need to equalize or even a shorted cell. The other thing is I have always used the bulb types so I don't see how it would do constant readings. I have heard of digital units but the price was stupid high.

 

[Mobilesport]

One of the values of doing the test is to see if all of the cells are the same. Finding one off can mean the need to equalize or even a shorted cell. The other thing is I have always used the bulb types so I don't see how it would do constant readings. I have heard of digital units but the price was stupid high.

I already tested all the cells and determined that none of them are low , and I think a bulb type would be fine because I don't need constant readings but just once a day be able to squeeze the bulb get the reading so i can determine SOC  ,  then squeeze again to get the water to go back into the battery without having to take the battery cap off every time.

 

[highdesertranger]

just because none of the cells are low today doesn't mean none will be low next month. once a month is enough for a SG test and you need to check all the cells. highdesertranger

 

[Mobilesport]

just because none of the cells are low today doesn't mean none will be low next month.  once a month is enough for a SG test and you need to check all the cells.  highdesertranger

My thinking was that I could test all cells once per month but also take a daily reading of just a single cell to get a idea of how full my batteries are , right now all I have is a voltmeter/ clamp on ampmeter  so I always have to wait for my batteries to rest to get a accurate voltage reading.

 

[jimindenver]

MS is looking for a daily gauge as to how his battery is doing like I use the pre dawn resting voltage. Not the best gauge but a hint at the state of the bank. I would know if something was up just because I knew what I expected every morning depending on how cold it was the night before. I had it to a point that I knew the GRP 27 would drop to 12.57v in the summer months and 12.4v in the colder night of fall. That was with the solar bring it up and holding float all day. Running a generator for two hours meant I woke to a 12,4v resting voltage every day.

 

[BradKW]

Quick question, playing around with my 2 t105's, initial test shows 12.5v in parallel. Hooked up a crappy charger that puts out 10v @ 10 amps. After 45min, batteries test at 13v and seem to drop gradually down with charger unhooked. What am I seeing here?

 

[Optimistic Paranoid]

Quick question, playing around with my 2 t105's, initial test shows 12.5v in parallel. Hooked up a crappy charger that puts out 10v @ 10 amps. After 45min, batteries test at 13v and seem to drop gradually down with charger unhooked. What am I seeing here?

Alright, this makes no sense whatsoever.  T105s are 6 volt batteries.  Hooked up in parallel, you'd see 6 point something volts, not 12.5.  And what kind of battery charger puts out 10 volts?

 

[SternWake]

MS, in the past you said you don't really care to get the batteries to 100% and you would just replace them when necessary.

It appears you have backed away from this to some degree.

True, the voltmeter is just a general indicator and depends on the load on the battery at the time, but it is a valuable tool when one views it often and remembers previous readings for comparison.

If you are concerned about how much time to run the generator to reach  XX%, your clampmeter over a battery cable while charging at absorption voltage can be pretty accurate.

A real battery monitor is the best way to know state of charge in a battery that is still being discharged, but even these are not 100% accurate and their accuracy drifts over time and needs to be reset.

Trimetric and victron both make battery monitors and are in the 200$ range, and require a Shunt be placed on the negative.

The following link is a budget battery monitor.  I have no idea how well it works, how accurate it is, or how durable it is or all of its functions.

http://www.ebay.com/itm/Digital-Cur...eter-DC-0-01-400V-0-1-300A-T9G2-/122132524958.

I do not think the semi permanent hydrometer idea would be easy to implement.

 

[SternWake]

Alright, this makes no sense whatsoever.  T105s are 6 volt batteries.  Hooked up in parallel, you'd see 6 point something volts, not 12.5.  And what kind of battery charger puts out 10 volts?

x2

Voltage is electrical pressure.  12.5 batteries fed by a 10v charging source would not work.

Your t-105s  in series, should be in the 12.72v range 24 hours after removing from charging source.

 

[BradKW]

Sorry, in series...and it's an old diehard charger I turned up in the warehouse, had to put new clips on. It reads 10v on my meter

 

[SternWake]

Meter is wrong or charger needs to be hooked to battery before it will exceed 10vDC output.

The fact that the batteries were 13+volts after a while says the latter.

PLug it back in, get those t-105s and L-16s upto a resting 12.72v+ Do not let them sit at 12.5v.

 

[Spaceman Spiff]

After 2 1/2 years experience:

I have two GC2 in series.  I test SG and check fluid levels ~ once a month.  The rest of the time I monitor by a Trimetric 2030.  Batteries SG = ~1.280 consistently and I reset the Trimetric at each testing.  With my usage I am almost always back to 100% by evening.  Batteries still going strong.

Look up 'battery watering systems' for some ideas on how to kluge a system to measure cell SG on demand.  But IMHO an amp counter (like the Trimetric) gives one more useful information on a daily basis:  it was noticing it was taking longer to get back to 100% that I discovered my refrigerator door gasket was leaking.

 -- Spiff

 

[ccbreder]

This is the latest wealthy battery monitor. Still cheaper than a digital SG device. http://www.pbase.com/mainecruising/smart_gauge

 

[SternWake]

 it was noticing it was taking longer to get back to 100% that I discovered my refrigerator door gasket was leaking.

 -- Spiff

My monitor has alerted me to several things which were not right, whether I was using more AH than expected, or I'd see the load and think that was too high, and start turning off everything to make sure, then finding something still on, like my parking lights, or one time, my fuel pump.

One still has to have the curiosity to notice abnormalalities, the monitor makes it that much easier, and the AH from full number is the golden ticket.

 

[Mobilesport]

[font=Verdana, Arial, sans-serif]Sternwake wrote[/font]
[font=Verdana, Arial, sans-serif] "MS, in the past you said you don't really care to get the batteries to 100% and you would just replace them when necessary.[/font]

[font=Verdana, Arial, sans-serif]It appears you have backed away from this to some degree"[/font]

[font=Verdana, Arial, sans-serif]Nope , I'm ok with getting them to 90% or as high as I can , I really have no choice since I'm boondocking full time , no shore power , Ever. [/font]
[font=Verdana, Arial, sans-serif]I'm just trying to get a idea of what my state of charge is everday so I can prevent from running the batteries down too far.[/font]
[font=Verdana, Arial, sans-serif]Btw , that Meanwell is working Super [/font]

 

[SternWake]

I'm just trying to get a idea of what my state of charge is everday so I can prevent from running the batteries down too far.

Btw , that Meanwell is working Super 

Well, how big of loads are you running when you are nearing your regular comfortable depletion level?

If you turn off all loads, how much does voltage rebound instantly, and then in 15 minutes?

If rebound is instantly to 12.1v, perhaps in 6 hours with no loads it might be 12.2+
There is lots of variability here with battery health and the battery design itself. Healthier rebounds quicker after load removal.

You could do a few tests, checking SG under load in the suspected depletion level, and know the load the battery is under from your clamp on meter, and narrow it down to a voltage under load.

Not totally accurate, but likely good enough.

The MEanwell rsp-500-15 is awesome, imo.

Being able to force a battery to a certain voltage and seeing the amperage required to hold it there is very enlightening.

 

[Mobilesport]

@ Sternwake

My last charging session

1:00pm------14.8 volts------50 amps ----fan off
1:20pm------14.8 volts------42amps  ----fan still off
1:30pm------14.8 volts------36 amps ----fan still off
2:00pm------14.8 volts -----26 amps ----fan still off
4:00pm------14.8volts------18amps-----fan still off
Quit charging at 4pm

Note the last time I charged before this time my batteries were lower and the Meanwells fan did come on during the beginning of charging
That time It looked like this
12:30pm----14.2 volts-------51 amps 
 2:00pm-----14.77 volts-----33amps
 4:00pm-----14.77olts-------26amps

 

[Mobilesport]

On the first one 2pm is supposed to be 3pm
And 4pm is supposed to be 5pm
Sorry , run out of time and the forum wouldn't let me edit