Bad batteries?

[cjdock]

I've had my wind mill going for around a month. It's a 6 ft diameter, 3 phase type built from Ed's windstuffnow kit. It puts out good current at the batteries. Today it's breezy, around 12mph winds and its putting out around 9 amps to the batteries. I have 4 US-1800 201 amp batteries, wired with 2 batteries in series, and the other 2 in series then both groups in parallel. I bought them brand new from a battery shop. I have an overcharge protector from mikeswindmillshop. That has been hooked up the entire time. The problem is that the batteries don't seem like they last the long on a full charge. I usually don't have much running from the batteries, just a switch, 2 little routers and the cable modem. The inverter shuts off if the battery voltage goes below 11.5 volts. The overcharge protector dumps to a 12v headlight if the voltage goes over 13volts. Until recently, that overcharge protector has never came on. The battery voltage never made it over 12.86 volts. I singled out each battery and read the voltage. One was 6.1 where all the rest were 6.26 so I figured that battery might be bad. I took it and it's partner out of the circuit and then just used the other 2 in series for my 12 volt system. The next day was windy and the over charge protector started being used, the headlight would fast off and on, never really staying on for more than a second or so each time. I though I was in good shape, maybe just 1 bad battery. I let the 2 batterys run my few devices and they only ran for a couple of hours and then the inverter shut off. Today I bought 2 different type of hydrometers, one from walmart and the other from an autopart store. With the batteries reading 6.2 volts each, the hydrometers say all the batteries are bad, no charge.....

I took the hydrometer to my car battery cells and they read great.

Did I somehow manage to kill these batteries? When my genny is running in a strong wind, with no load on it from the batteries, I measured up to 40volts afetr being rectified...is that bad?

Sorry for a long winded posting, I just wanted to include as much info as possible. 270.00 for batteries that are 1 month old that are possible bad....just depressing..

[Flux]

At best those batteries are undercharged. Full charge will need over 14v, so set your dump control to about 14.2v.

It may be that one battery is sick and preventing you reaching higher volts or it may be that you are not supplying the self discharge.

If you can, charge all 4 batteries by some other means so that you can get them up to about 8v. They will need equalising for a while.

When left off charge for a day they should measure about 6.4v.

When you have got them back fully charged, try again and see if the wind generator can get them up to 14 and a bit volts.

Flux

[cjdock]

I was thinking along those lines and have placed the low voltage battery on my car charger (set at 6 volts).

Thanks for the advice, I hope it works! Guys like you, Nando, Ed and a bunch more really make this forum a great place. I can't thank you guys enough for the time you put into this and the info you provide. Thanks!

[Nando]

The hygrometer says --- but not information

This is a classic battery "murdering" job. -- Sorry to say it !

90% of the bad batteries are Murdered by their owners !!

Even though you do not have a larger system, you need to do maintenance.

From now on record, now daily, the hygrometer readings and the battery voltage LIKE :

String1

DATE batt1..............Batt2

5. -7 6.25 1100 1250 1280 6.30 0000 1050 1175 include water usage
   
5. -8
   
5. -9
   
   

And if possible do a mid range charge ( the batteries being charged ) to show the charging voltages that will tell you how the batteries are behaving RECORD : MID

Set the charging ( bulk) for the next few days to 2.46 volts/cell YOU NEED TO DO A DEEP equalization charging cycle @ 0.1C to 0.2C amp-hour for 3 or 4 hours -- that may have to be done at least 3 or 4 times to bring the batteries to full capacity.

The batteries may have film sulphation that needs to be eliminated -- a good electronic desulfator with 50+ amps capability should be good, but they are not available, just the below 10 amps peak pulses that may take a long time to do the cleaning job.

Discharge the batteries to 1.75 volts/cell and bulk charge 2.46 volts/cell for 3 pr 4 cycles and send it to me directly to tell you have to do next.

We have been doing this type of salvage to 12 Trojan L16HC battery bank that was going down bad, up to know we salvaged and stabilized 10 of them, we will be treating the 2 bad ones that have one Bad cell each with EDTA to see if they are salvaged.

You need to do the deep charging until the Hygro shows stable high 1230+ values in all cells.

So for the time been allow the wind mill to charge heavy and set the limit to 14.8 volts, it would be the best to do battery salvage.

Nando

[wooferhound]

Why are you using an inverter to power your 12 volt devices

just run the 12 volts straight to your routers and modems and leave out the losses of going up to 120 volts and then back down to 12 volts again . . .

[cjdock]

Hello Nando,

Thanks for the reply.

I have a couple questions.

--YOU NEED TO DO A DEEP equalization charging cycle @ 0.1C to 0.2C amp-hour for 3 or 4 hours -

What does the .1C mean?

-The hygrometer says --- but not information

None of the balls floated so I guess this means 0

-Set the charging ( bulk) for the next few days to 2.46 volts/cell

does that mean leave the batteries all connected and then charge them all together (bulk) I have taken one out of the bank and placed it on a car charger at 6 volts, 10 amps. It's been 24 hours and now the battery is finally bubbling and spitting on the top of battery. It still only reads 6.8 volts without the charger connected to it and no load so it's still not up to where it should be, I imagine. Am I hurting the battery by charging it this long at 10 amps or should I let that keep going until it reaches 8 volts?

I have to purchase a variable volt battery charger to be able to charge at specific volts that you suggest. I'll also have to purchase a electronic desulfator, any recommondations?

-film sulphation

Could this be the gray film on the inside of the battery caps? Also when I pull out a sample of the battery acid into the hydro, its cloudy and gray...

Thanks for your help. I'm not sure exactly where to start.

[Flux]

You need to measure the volts when charging.

If you have it bubbling then you are up to gassing volts, check it with your voltmeter on charge to see what you get.

6.8 v off charge is probably reasonable and if it holds to 6.4v when off charge for 12 hours then you have got it back up.

You can reduce the charge rate once it is gassing and leave it gassing gently for a while, it is not a good idea to hold the 10A after it has reached gassing volts, but with that size battery it will not be disasterous for a few hours. The aim is to keep it at gassing voltage until the SG on the hydrometer stops rising. If you only have the thing with floating balls then it will not be much of a guide.

If that was the worst one then you are likely to be able to recover the others.

When they are all back up you will have to find out why they went flat in the first place. Your dump load was set far too low, but you claim they never reached 13v.

You will have to find out if you are drawing more out than the windmill is providing or whether there was another problem.

Flux

[nothing to lose]

Maybe some of his are other volts. He should check that to be certain.

My Linksys Router is 7.5Vdc, I just looked at it to see.

I been digging through a pile of wall worts looking for a 12Vac one for a radio.

 I finnally did find one, but of all the ones I looked at only 1 was actaully 12Vdc.

Nearly every voltage from 15v down as AC or DC in a big box, only 2 were 12V, one AC one DC.

[Nando]

You start by doing a deep equalization charge as indicated @ 2.46 v/cell

One battery bad, therefore the string is not fully charged -- so do the whole string.

You can place each battery with the 6 volts charger and bubble each one of them as indicated if the wind mill can not do it well.

Set the dump as indicated before.

The batteries If you leave them for a while to hard charging that is the equivalent to deep equalization that is what you need to do to salvage the battery -- the 6 volts hit with 10 amps for about 24 hours causing bubbling --an indication that you have been able to fully charge the battery as the battery is with a possible some sulphation -- discharging the battery and another charging cycle will assist in further removing the sulphation.

I gave you 2.46 volts/cell so for you to calculate the final voltage for a 6, or 12 volts or even 24 volts string.

So for 6 volts is 3 cells * 2.46 = 7.38

for 12 volts is 6 * 2.46 = 14.76 volts

for 24 volts is 12 * 2.46 = 29.52

When the battery has sulphation one needs to hit the battery HARD and make it BUBBLE and keep it for 2 or 3 hours -- this for the current to go deeply in the plates and do the conversion and remove the sulphation -- discharge to 1.75 volts /cell and repeat the charging cycle.

Measure the batteries during charging, Voltage and hygro to observe how one battery is charging against the others in the string, the weak one will have lower voltage that the good ones -- the very new may have the lowest voltage -- notice which is new and which is old and low voltage.

I do not have the time to really explain such battery behavior.

The 6 volts battery that reads 6.8 volts charged and disconnected is telling you that is fully charged and possible "cured" from sulphation, a discharge cycle may tell you if you have full amp-hours capacity --so do it -- and charge again.

If one string is constantly up/down in charge/discharge cycles and the discharge is lower than 1.84 v/cell, then the string needs periodic and often deep equalization - for this reason is always necessary to have a good hygrometer and take reading constantly if you want the batteries to last.

I learned this from my family electrical equipment that had large open lead acid batteries and Edison NiFe batteries -- that with the proper maintenance were maintained for many years -- the lead acid were abandoned around 10 years ago ( bought in the early 1900) and the NiFe still alive and well -- now a bit hard to find Lithium Oxide for the yearly cycle maintenance periods -- KOH oxidizes if exposed to air - so it needs periodic replacement -- it is covered with film of mineral oil to reduce the exposure.

The gray ( gray toward whitish) films in some batteries types is a sulphation product.

An electronic desulfator will assist in the "cure" but if the batteries are not properly maintained they will not get good desulphation "cures".

I need to quit and go to a meeting.

Nando

[cjdock]

1 of my devices is 12v, the rest are not.

[Ungrounded Lightning Rod]

--YOU NEED TO DO A DEEP equalization charging cycle @ 0.1C to 0.2C amp-hour for 3 or 4 hours -

What does the .1C mean?

One-tenth the rated capacity (per hour).  I.e. if it's rated at 80 amphours, 0.1C would mean charging it at 8 amps.