It is currently Wed Mar 29, 2017 3:09 pm



Welcome
Welcome to imhotep's labs

You are currently viewing our boards as a guest, which gives you limited access to view most discussions and access our other features. By joining our free community, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content, and access many other special features. In addition, registered members also see less advertisements. Registration is fast, simple, and absolutely free, so please, join our community today!


Post new topic Reply to topic  [ 30 posts ]  Go to page 1, 2, 3  Next
Author Message
 Post subject: Dead batteries
PostPosted: Sun Mar 13, 2011 3:47 pm 
Offline

Joined: Mon Jan 10, 2011 11:23 pm
Posts: 26
Has thanked: 5 time
Have thanks: 0 time
HI,
excuse the delay
I created this new topic because the conversation of the batteries was already off topic

This is the continuation of the discussion on topic: tuning-the-motor-using-the-neon-bulb-t50-30.html


mbrown said:
"We are off topic here so maybe you should start a new thread in the batteries section.

Yes C20 is about discharging in 20 hours. If you have a 12v 10Ah battery and we want to discharge that in 20 hours we divide 10Ah by 20h to give the discharge rate. That is 0.5 amps.

We then choose a load that will draw 0.5 amps and time how long it takes to discharge. If the battery is in reasonable condition it will discharge in 20 hours + or – 10%.

If there is a big difference there is a problem with the battery.

Lead acid batteries slowly shed material from their plates, if half this material has gone you will have half the capacity. Drawing power at a higher discharge rate will cause more material to be lost.

If you battery has only 1/10th of its rated capacity I would use a smaller amp draw till it recovers as the plates that are working may suffer further damage but for charging I would use the C20 charge rate and drive the voltage as high as it will go when charging.

Can you check the specific gravity of the acid? You may need new acid if it is too low."


yes, my batteries need acid, I measured the weight of water and these are the pictures of the measures, also measured in a functional battery to make sure that the problem was not the measuring device

Image

Image

Image

Image

Image


Today, after the black battery being charged (11.6V) called to a motor, it is possible to register a current of 50mA, it was 6 hours to discharge, after 6 hours the voltage on "disconected battery" was 9.6V, the engine was still working


I can do something to regain some of these batteries?

thanks


Top
 Profile Send private message  
 
 
 Post subject: Re: Dead batteries
PostPosted: Sun Mar 13, 2011 3:53 pm 
Offline

Joined: Mon Jan 10, 2011 11:23 pm
Posts: 26
Has thanked: 5 time
Have thanks: 0 time
the pictures not was working

Image
Image
Image
Image
Image


Top
 Profile Send private message  
 
 Post subject: Re: Dead batteries
PostPosted: Mon Mar 14, 2011 1:45 am 
Offline

Joined: Tue Dec 23, 2008 1:44 am
Posts: 397
Has thanked: 6 time
Have thanks: 12 time
If there are no short between cells or disconnection, I think the battery stil can be recovered. Just keep sending voltage spike the battery. Use the strongest spike maker you has or tune your circuit to produce strongest spike.

Once the sulfation clear up, use normal charge.


Top
 Profile Send private message  
 
 Post subject: Re: Dead batteries
PostPosted: Mon Mar 14, 2011 7:41 am 
Offline
Moderator

Joined: Wed Aug 13, 2008 11:48 pm
Posts: 1016
Has thanked: 0 time
Have thanks: 27 time
The left cel looks good.

If there is no short it might be worth putting new acid in

How did you get the top off? looks like a neat job


Top
 Profile Send private message  
 
 Post subject: Re: Dead batteries
PostPosted: Tue Mar 29, 2011 6:24 pm 
Offline

Joined: Mon Jan 10, 2011 11:23 pm
Posts: 26
Has thanked: 5 time
Have thanks: 0 time
Hello everyone, sorry for the delay in my reply

sucahyo and mbrownn
my batteries are still not working properly, have a very low capacity
I was watching new batteries but they are very expensive, I added some sulfuric acid and expect to increase capacity

I like to make a mechanical "Tesla Switch"of 4 batteries, hopefully obtain planning an overunity effect, someone here already experiemntou build one of these?

I can use my batteries even with low capacity?

mbrownn,
hi,
well, to open the battery was simple, gently knocked on the battery cover off, I had to saw out the two terminals and so was possible to take the lid off.
the cell at right was completely rotten and broke terminal

thanks


Top
 Profile Send private message  
 
 Post subject: Re: Dead batteries
PostPosted: Wed Mar 30, 2011 2:12 am 
Offline
Moderator

Joined: Wed Aug 13, 2008 11:48 pm
Posts: 1016
Has thanked: 0 time
Have thanks: 27 time
With a Tesla Switch I would imagine all your batteries need to be the same voltage and capacity.

If your battery has the voltage but low capacity it is probably sulphation.

What is the condition of your battery? To know this you need to give answers to the following questions.

What is the battery rated at?

What is the resting voltage?

What is the specific gravity of each cell?

This will give a clue to the battery condition but even better is the cold cranking amps.

What is the voltage on a heavy load or the amps measured on a battery tester?

It may be the case that one or more cells are dead, if the cell is shorted there will be little you can do because the plates will probably break if you try to dismantle them. If they are dead but not shorted, there is a good chance that they can be recovered.

Using a small radiant charger it will take quite a while to bring back to health a big battery.

Using an 80mA fan it took a week to bring back a 7Ah battery.

I am using a 450mA SSG now on two 60 Ah batteries, one recovered in a week and the second is still slowly improving but still not back fully after 2 weeks.

I run the SSG until there is no further increase in volts for 24 hours, then drain the battery down 10% of what ever the standing voltage is and then charge again. I repeat this until the battery is back.


Top
 Profile Send private message  
 
 Post subject: Re: Dead batteries
PostPosted: Wed Mar 30, 2011 2:44 am 
Offline

Joined: Tue Dec 23, 2008 1:44 am
Posts: 397
Has thanked: 6 time
Have thanks: 12 time
c_henriques, I think you should try converting to alum. Using alum solution instead of sulfuric acid. to prevent more corrosion.

I think it would be no problem using small capacity battery.


Top
 Profile Send private message  
 
 Post subject: Re: Dead batteries
PostPosted: Mon Apr 25, 2011 1:27 am 
Offline

Joined: Mon Jan 10, 2011 11:23 pm
Posts: 26
Has thanked: 5 time
Have thanks: 0 time
hello,
I'm sorry for never saying anything,
but the truth is that I have had a lot of work, I am student of engineering physics and have not had time to come to my garage where I got all the material to perform the tests that you suggested me with my batteries, however they have been continuously charged and discharged with a fan and with the rate c20

hopefully later this week perform the tests and experiments and then say something about

thanks


Top
 Profile Send private message  
 
 Post subject: Re: Dead batteries
PostPosted: Wed Apr 27, 2011 3:25 am 
Offline

Joined: Tue Dec 23, 2008 1:44 am
Posts: 397
Has thanked: 6 time
Have thanks: 12 time
We all have life to live too :).

I recently refill a no longer charging motorcyle lead acid battery with alum water. It retain charge better now. Usually the light would not lit if I turn on the key, now it is always lit :).


Top
 Profile Send private message  
 
 Post subject: Re: Dead batteries
PostPosted: Thu Apr 28, 2011 12:47 am 
Offline
Moderator

Joined: Wed Aug 13, 2008 11:48 pm
Posts: 1016
Has thanked: 0 time
Have thanks: 27 time
Interesting, I haven't found alum here but there is a product called tawas, I think it is alum.


Top
 Profile Send private message  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 30 posts ]  Go to page 1, 2, 3  Next


Who is online

Users browsing this forum: No registered users and 0 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
suspicion-preferred