watering batteries?

[birdhouse]

hey-

the facts:   i have four trojan t-125's connected in series for a 24 volt bank.  they are about one year old.  these are charged with 390watts of evergreen panels.  i use a ts-60 in the pwm mode (not diversion) as the charge controller.  i have it set at the second to highest with the internal dip switches.  this ends pwm at 29.6, and float at 26.8.  i do have the temp sensor on the bank.  i have manually equalized them five times, for at least an hour each time over the past year.  this is a vacation property, so they have only been through 20 cycles, and sit at float, or close to it unless the panels get too much snow on them.  the mount is variable in angle, and is set steep for the winter, so snow melts/slides off quickly. 

side note: my fellow property owner actually bought these, and they tipped over in his truck. DOH!   they spilled a little, but not enough that the plates were ever above the liquid level.  i topped them off with distilled water, as per the supplier's instruction, and haven't had to water since. 

the question:  i have not had to add a drip of water, except for mention above, to these batteries since i bought them.  i check them semi-regularly, but they are always right where they are supposed to be, and never change level on any of the cells.    is this normal? 

another question:  i have never drained them down too hard.  the lowest resting voltage i have put them to is 24.4volts.  this combined with mostly float and only 20 or so cycles per year.  any idea of longevity for this bank? 

yet another:  some of the cells obviously lost some acid during the idiotic tip over event.  is there an easy way to tell which cells lost acid, and is it worth replacing the acid?  the hydrometer is so close between cells, it is hard to tell from that. 

thanks for any wisdom!

adam

[Watt]

hey-

the facts:   i have four trojan t-125's connected in series for a 24 volt bank.  they are about one year old.  these are charged with 390watts of evergreen panels.  i use a ts-60 in the pwm mode (not diversion) as the charge controller.  i have it set at the second to highest with the internal dip switches.  this ends pwm at 29.6, and float at 26.8.  i do have the temp sensor on the bank.  i have manually equalized them five times, for at least an hour each time over the past year.  this is a vacation property, so they have only been through 20 cycles, and sit at float, or close to it unless the panels get too much snow on them.  the mount is variable in angle, and is set steep for the winter, so snow melts/slides off quickly. 

side note: my fellow property owner actually bought these, and they tipped over in his truck. DOH!   they spilled a little, but not enough that the plates were ever above the liquid level.  i topped them off with distilled water, as per the supplier's instruction, and haven't had to water since. 

the question:  i have not had to add a drip of water, except for mention above, to these batteries since i bought them.  i check them semi-regularly, but they are always right where they are supposed to be, and never change level on any of the cells.    is this normal? 

another question:  i have never drained them down too hard.  the lowest resting voltage i have put them to is 24.4volts.  this combined with mostly float and only 20 or so cycles per year.  any idea of longevity for this bank? 

yet another:  some of the cells obviously lost some acid during the idiotic tip over event.  is there an easy way to tell which cells lost acid, and is it worth replacing the acid?  the hydrometer is so close between cells, it is hard to tell from that. 

thanks for any wisdom!

adam

What was/is the SG of each cell? 

[97fishmt]

Hi Adam,

I didn't realize you were doing a 24 volt system.  Your mill wont work real well at that voltage.  The motor you have should work OK for 12 volt, but 24 is out of the question.

For batteries I got some like that with a similar history and did add some acid to bring the sg up and they have been doing OK.  I water about a gallon every 3 months (12- 2 volt cells).  If they aren't using water then you aren't charging them enough.  Also I have a set of T-105 's over 8 years old still going strong being on float like your system.  Don't worry about using them that's what they are for.  Just keep them charged.

My truck broke last time I was coming home from the cabin and I left a ametek  99 volt up and didn't leave the dump load hooked up and it has been windy!  I got my truck fixed today and need to get up there.  Silly me for not just leaving the dump hooked up.

[birdhouse]

watt-
i don't remember.  i usually use voltage to roughly determine SOC.  it was over a year ago.  it's probably a good time to check them all again, and record the results.  next time i'm up there i'll do just that.  still too much snow/mud to get there currently. 

mike-
i know 24V is not ideal for my mill, but i hope it does okay.  on the bench the motor hits 24V @  220RPM.  i didn't think this sounded terrible for 8.5' rotor.  maybe i'll be forced to go mppt.  it is my first unit, so maybe it's poor 24v performance will force me to build a 10' axial, and i can find a new 12V home for my mill.   

as far as raising the settings on the ts-60...  it would then be set on the highest setting, also listed for L-16's.  this would put PWM @ 30V,   float @ the same 26.8, and equalize @ 30.6V. 

this sounds a little high, but i could try it.  with the current settings, i can hear them bubble in PWM, with the occasional big blurp of a big bubble. 

i hope that little ametek doesn't overcharge your batteries!  sounds like your bank is rather large, so hopefully it just gave the bank a long duration equalization. 

adam

[madlabs]

I'd have to agree that it sounds like they aren't getting charged enough. I water my batteries about every 6 months and use about 3/4 of a gallon. I have 10 golf cart batteries. I do live on them so they are constantly in use.

When some of the electrolyte got spilled, how much water did you use topping them up? Did you check the SG after filling and charging?

Jonathan

[97fishmt]

Hi

I learned something new today about these servo motors.
I did a lot of reading on the fanuc site.  It turns out that the
voltage numbers on the name plate are for the pulse coder.

Fanuc drive systems all run with a voltage of 200 to 240 volts
on the bus.  (The alpha system is 400 volt)  So that makes more
sense looking at other servo motors and the way they rate them.

The standard drives use 200 volts.  So the motors are wound for that.
It's the amplifier that makes the motors do different things.  But you know
the big motor I just got is a custom and has a 300 volt bus.

It makes it all clear as mud I know.  

Your motor should work OK at 24 volt, a little fast,  it would work much better
at 12 volt though.  Nice going, I haven't played with
a fanuc yet.

I'll be going up to the cabin next week to trudge through the snow.  I don't
think I'll take the snowmobile, I think towing it broke my truck.  (busted a
couple teeth off on the pinion gear in the rear differential).

[birdhouse]

jonathon-  i'm wondering if the lack of water consumption is due to the limited cycles, or possibly the lack of acid within the cells.  either way, i temped to put the controller to the "L-16" setting. 

when my cohort arrived with the batteries, he was all flustered and told me the guy at the supplier told him to get em charging and add water as soon as possible.  i didn't slow down and think to mark the cells water was added to, and or measure how much water was added.  this is my fault, and i knew better, but joined the crazed deal, and topped em off and connected them to the panels. 

later that day after the sun went down i took hdro readings of each cell, and they were all really really close, but not pegging the meter as tip top.  like i said, none of the plates were showing, and i'll bet i added a 1/4 cup at most to the lowest cells.  the more i think about this, i need to document each cell after they have sat for an hour or so, and possibly use a dropper to add acid to the lowest reading cells.  then measure again.  there were some cells that didn't lose anything and needed no water, so with some deductive reasoning, i should be able to figure out which read the highest, and match the lowers by adding maybe 6 drops of acid at a time?  then let them cycle a few days, and hope they meet the highest cells.   

does this sound like a good idea?  any idea on how much acid to add at a time?  i'm guessing it isn't much. 

mike-  i originally bought the fanuc motor to make a 12v mill.  then after LEARNING, i decided 24 volt would be a far better choice for an expanding system.  i knew this wouldn't be ideal for my motor, but i'm in a pretty high wind area, so figured it would still do decently well.  i guess i'll find out this spring.  spent over 20hrs last weekend welding on my tower pipes ect.  it's really close to ready for install!  cable is in my living room right now!  footings poured last spring. 

back to fanuc...  are you saying the voltages on the name plates is irrelevant?  only the rpm and amps make a difference in these motors?  i do know that fanucs are highly looked upon.  i got mine "new old stock" and it goes for 4-5k new. 

your new monster is 300v?  isn't that good?  or do you think it will be too slow (@24v) to match to blades?  if that's the case, i've always wanted to find a motor like that to hook to a giant VAWT with no tower to see if i could get 50-100 watts on a regular basis.  maybe even if gearing was needed.  we don't live too far apart if you need to find a new home for it.   

thanks again for the wealth of info!

adam

[birdhouse]

mike-
forgot to add-  bummer about the truck!  you must have been doing some serious boggin/trailer towing to blow out a diff!  were you trying to tow a 24' trailer with a ranger?   

atleast it is fixed now!

adam

[97fishmt]

  Hey adam,

Yeah, that's kinda what I got from reading about the controllers for those motors.
I'm not sure about the lower voltage ones like 70 or 90 volt but I don't look into those.  I thought I'd dig into it after you said you were getting your motor to do 24 volt at 220 rpm.  It didn't make sense with the name plate of that motor.

  So yes it's a new ball game looking at servo's for me,  they are made as servo systems so that means the motors are made to work with  the other electronics.

  I don't try and get any of the older ones anymore they are just to big and heavy.  If you look again for one to better suit 24 volt look for a date code after 1998 or maybe even 2000, then they have the neo magnets in them and usually 8 pole and about 1/2 the size and weight of what it is replacing per kw.

  The 300 volt motor should be perfect for 24 volt charging.  It is about the same size as the motor I use now but, for 12 volt.  The older magnets in the one I use now.  So twice the power out of the same package with the new magnets.  My turbine now is a 12 hp motor.  This one is 20hp. Same size and weight.

  But the beta fanuc's don't do the neo's.  The alfa ones do but they aren't cheep yet.  Any how just rambling.  The truck thing wasn't as bad as you thought,  a toyota towing a 10' trailer with a 800 rmk on it.  My diff was just worn out.  My problem is I changed to 5.29:1 gears and lockers front and rear for bigger tires (35's)with chains on all fours to get through the snow.  I don't try anymore either, so after I wear these tires out I'll go down a size.  Too stressful for a 22re toyota.  

  I'd love to help you put up your mill or help on any of the cabin life sort of stuff.  Not that you need it, I've done it all myself at my place, but sure could use help sometimes.  So I know how high the hurdles can be.  I get down towards Portland sometimes.  

  Mike

[birdhouse]

mike-

i hope we aren't hijacking too far.  can "servos" be added to the title? 

yea, i never looked into any of the lower voltage units either.  mine is a 140 volt.  nothing runs on 140volt, so i asked my machinist friend how this was.  he said they use very complex controllers to run these things.  you are saying that they mostly run on 200 to 240 volts, so maybe the 140v sticker is what you input to the controller for that motor?  just trying to consolidate in my head.  i think they use a hybrid magnet.  like a cobalt something or other.  mine is soooo electrically stiff i find it hard to believe it's ceramic. 

have you checked out any of the yellow caps?  i found a 110lb fanuc yellow cap that was DC and looked to have good sticker ratings.  it just went to high on ebay. 

so your saying your gonna give me that 300v motor right?   

that pour toyota trying to push chained up 35's. on all four...  yea, that'll blow a diff.  i'd love to have lockers in my dakota.  it has a small v-8, and i've been stuck in 4wd with chains on all four tires trying to get up to my place, but god, i pray for the tranny in those conditions, and i only run 32's.  standard gearing. 

i'm beginning to think you're part of the TOYOTA club... 

aka "Take Off Your Oversized Tires A$$hole"       

i PM'd you also.

adam