Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • 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.

Students Click Here

Brand new batteries low SG

Brand new batteries low SG

Brand new batteries low SG

Hi everyone, this is a great forum I hope you can help me with a battery concern. I have 2 Trojan SCS150 12v 100ah Deep Cycle batteries I bought brand new in october. When I got them home the voltate read 12.5 on both batteries so I connected them in parallel and fully charged them with a 3 stage charger. The resting voltage, no charge no load, after 12 hours was 12.8v. The specific gravity was 1.225-1.235 on all cells. The electrolyte levels are where they should be and it looks clear and clean. Ive read you have to break in the batteries by shallow cycling them 50-100 times. I started cycling them using a 8-10 amp load to 80% DoD. I noticed the voltage would sag to around 12.1v almost immediately, which seems like an excessive drop for such a small load. Also, they seemed to only have about 50-75% capacity. After a couple cycles the resting voltage increased to 13.1 and it sags to about 12.3 with the same 10 amp load. Ive cycled them about ten times so far and capacity doesnt seem to be increasing. I equalized them at 15.5v for 3 hours stopping every hour to check SG, then once for 2 hours straight. At resting voltage(12 hours)SG hasnt risen at all... its still 1.225-1.235. Ive read that new electrolyte needs time to properly mix...is this true? I know new flooded batteries wont deliver 100% capacity right away and Im hoping thats all this is. Would really like to hear what you think. thank you.

RE: Brand new batteries low SG

I've never heard of all this break-in stuff before on LA batteries! Mixing??!! Cripes. As soon as you charge once any mixing will be done. But then it's probably completely mixed when it's added.

Cycling batteries is how you wear them out. I wouldn't do it.

I'd check your measurements to make sure your instruments aren't lying to you.
I'd confirm the temperatures are correct because LA battery performance is more connected to temperature than anything else.
I'd contact Trojan, an excellent company, and put your questions directly to THEM since you have your numbers in-hand.

Keith Cress
kcress - http://www.flaminsystems.com

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.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


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:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close