×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Are you an
Engineering professional?
Join Eng-Tips Forums!
• Talk With Other Members
• Be Notified Of Responses
• Keyword Search
Favorite Forums
• Automated Signatures
• Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

#### Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

# How to discharge a 2V cell?

## How to discharge a 2V cell?

(OP)
I have a few 2V lead acid deep cycle cells, each of 1080Ah, when discharged over 10 hours. I would like to discharge them, one by one, to test their behavior (health). How do I discharge a 2V cell?

So I imagine discharging at app. 200A, for maybe three hours. 200A at 2V is 400W.

So I guess I need a load, with a resistance of R = V/I = 2V/200A = 10microohm.

How can I find / build such a load?

### RE: How to discharge a 2V cell?

Check your maths - 10mΩ, not 10μΩ.

A length of heavy cable in a large drum of water?

### RE: How to discharge a 2V cell?

Note that your connectors will also contribute to the series resistance. Note also, the battery's internal resistance will have significant impact at such high currents. Typically, they are intended to be discharged at C100, not C5 as you intend. At C5, you'll only get about 70% of the rated capacity, which means that your battery will barely make it to 3 hrs.

TTFN
FAQ731-376: Eng-Tips.com Forum Policies

Need help writing a question or understanding a reply? forum1529: Translation Assistance for Engineers

Of course I can. I can do anything. I can do absolutely anything. I'm an expert!

### RE: How to discharge a 2V cell?

(OP)
Oops, it should be 10miliohm, not microohm. Is it not possible to edit my post... I can't see a way :(

### RE: How to discharge a 2V cell?

No, there is no edit function. In any case, you'd need something like a chunk of battery jumper cable, but still short, and a good way to attach to the battery to minimize parasitic resistances. Sort sort of current meter is necessary to ensure that you are discharging at the rate you think you are.

TTFN
FAQ731-376: Eng-Tips.com Forum Policies

Need help writing a question or understanding a reply? forum1529: Translation Assistance for Engineers

Of course I can. I can do anything. I can do absolutely anything. I'm an expert!

#### Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

#### Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Close Box

# Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

• Talk To Other Members
• Notification Of Responses To Questions
• Favorite Forums One Click Access
• Keyword Search Of All Posts, And More...

Register now while it's still free!