×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

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!
  • Students Click Here

*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

Electronic load testing - NiMH batteries - Energy storage

Electronic load testing - NiMH batteries - Energy storage

Electronic load testing - NiMH batteries - Energy storage

(OP)
Hey everyone,

I recently found a way to recondition used cylindrical NiMH batteries pretty well (typically those used in the Honda Insight series). However, I want to know whether the batteries will hold practically in the real world outside the laboratory. My aim is to utilize these batteries as back-up storage for a house or maybe even put them back into the car. These batteries have a nominal voltage of 7.2 Volts and a rated capacity of 6.5 Ah (Though the reconditioned pack is obviously lesser than this value). To succeed in this, I'm aware that I need to test these batteries and mimic real world situations.

I purchased the Agilant N3301A/N3304 electronic load tester to help me do just that. The device can do a lot with various settings - CC discharge, CV discharge, constant resistance discharge, pulsed discharge, transient discharge etc etc. I'm completely new to this so my question is:
What tests should I typically run to mimic that of the battery being deployed in a hybrid vehicle? In addition to that, what tests should I perform to know whether these batteries can sustain being used as a back-up storage center for residential purposes? In other words, what are the key things to look out for during these tests.

All inputs on different tests to perform are hugely appreciated! I'm still an amateur at this, but I'm keen to learn and continue developing. Thanks for the time guys!

RE: Electronic load testing - NiMH batteries - Energy storage

I don't think it is that important to get the duty cycle exactly right.

My off grid 200Ah system in winter charges at 20A for 2 hours from the generator, 4 hours at say 3A from the panels, and then gently discharges that over the remaining 18 hours.

In summer it follows the usual sun curve peaking at 25A charge at mid day. By then the pV controller takes over and limits the charge current to float the batteries.

Max current draw would be 60A, that would be unusual, but 30A is not unusual for an hour at a time.

The duty cycle in a car would depend entirely on the details of the cars architecture, control systems, and driving cycle.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

RE: Electronic load testing - NiMH batteries - Energy storage

I can't speak much about house batteries. But have noted in automotive applications, there are two types of operators - one will run it to dead empty before recharge, often just enough to get home, then charge overnight. Sometimes a few small charges, just to get to the next stop each time.
The second type is terrified of getting stranded and will not let the batteries drop below around half, roughly.
The point being, make sure you factor charge cycles that the average user might put them through - many don't know the best way to treat a battery! I would suggest it's probably just as important as discharge cycles. More so, maybe, as in automotive service, the discharge cycle can be so hugely variable.

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


Resources

eBook - Integrating the Engineering Ecosystem
Aras Innovator provides multiple options for integrating data between systems, depending on the scenario. Utilizing the right approach to meet specific business requirements is vital. These needs range from authoring tools, federating data from various and dissimilar databases, and triggering processes and workflows. Download Now
Research Report - Simulation-Driven Design for SOLIDWORKS Users
In this engineering.com research report, we discuss the rising role of simulation and the paradigm shift commonly called the democratization of simulation. In particular, we focus on how SOLIDWORKS users can take advantage of simulation-driven design through two analysis tools: SOLIDWORKS Simulation and 3DEXPERIENCE WORKS. Download Now
White Paper - Industry 4.0 and the Future of Engineering Education
With industries becoming more automated, more tech-driven and more complex, engineers need to keep their skills and knowledge up to date in order to stay on top of this wave—and to be prepared for the Industry 4.0 future. The University of Cincinnati offers two online Master of Engineering degree programs designed specifically for practicing engineers. Download Now
eBook - The Design Gridlock Manifesto
In this eBook, you’ll learn 6 ways old CAD technology slows your company down and hear how design teams have put those problems to rest. “The Design Gridlock Manifesto” shares first-hand modern CAD experiences from 15 companies around the world. Download Now

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