Bill Darden

Last Update on June 10, 2021

Car and deep cycle lead-acid battery answers to Frequently Asked Questions (FAQs), tips, manufacturer's information, references and hyperlinks are contained on this consumer oriented website about car, powersports (including motorcycle), truck, boat, marine, lawn and garden, recreational vehicle (RV), solar, UPS and other starting and deep cycle applications.

Eurobat Car Battery Construction

Car Battery Construction (Source: Eurobat)

Car and Deep Cycle Battery Frequently Asked Questions (FAQ) 2021

This consumer oriented FAQ contains answers and information about lead-acid batteries used to start car, truck, boat, recreational vehicle (RV), powersports (including motorcycle), motor home, tractor and other engines. It also answers questions about golf cart, Electric Vehicle, traction, motive, solar, standby, stationary, Uninterruptible Power Systems, network, industrial and other lead-acid batteries used in deep cycle applications. It covers charging (and battery chargers), effects of driving habits, testing, buying replacement batteries, installing, myths, overnight draining, preventing and removing sulfation, storing (or winterizing), jump starting, and other topics about car (starting) and deep cycle batteries. The FAQ was last updated on June 10, 2021.

Lead-Acid Battery Manufacturers and Brand Names List 2021

This popular and frequently updated list contains hyperlinks to lead-acid battery manufacturers' and large distributors' websites, telephone numbers, battery brand names, replacement selector and fitment guides, and private labeling information. The file size is approximately 166 KBytes. This list was last updated on June 10, 2021.

Battery Information Links List 2021

This frequently updated list contains hyperlinks to product information associated with lead-acid batteries, for example, alternators, cables and wiring products, chargers, converters, desulfators, inverters, isolators, low voltage disconnects, jump starters, regulators, switches, test and monitoring systems, etc. The file size is approximately 128 KBytes. This list was last updated on April 16, 2021.

Battery References Link List 2021

This frequently updated list contains hyperlinks to reference resources about lead-acid batteries, for example, 42-volt, associations, books, business directories, dealers and distributors, FAQs, glossaries, history, hyperlink lists, magazines, magazine articles, manuals, primers, newsgroups, safety, standards, etc. The file size is approximately 66 KBytes. This list was last updated on April 16, 2021.

Temperature Compensated Battery State-of-Charge (SoC) Tables

When printed, this Excel spreadsheet produces a single page that contains tables with the temperature compensated Specific Gravity and Open Circuit Voltage State-of-Charge measurements for Flooded Standard (Sb/Sb), Flooded Low Maintenance (Ca/Sb), Flooded "Maintenance Free" (Ca/Ca), AGM (Ca/Ca), and Gel Cell Valve Regulated Lead Acid (Ca/Ca) lead-acid battery types. Please see Section 7.1 for battery type descriptions. The file size is approximately 9 KBytes and was last updated on October 2, 2017 and converted to "SoC.xlsx" on December 6, 2020.


A zipped version of all the above current battery related Web pages, graphics and spreadsheet on this website can be easily down loaded to your computer. Just create a directory for the FAQ and unzip into it. The file size is approximately 1,041 KBytes and was last updated on June 10, 2021.

I will be happy to answer your lead-acid battery and charging questions within 48 hours. Please inclose a valid "Reply To:" e-mail address in your message and include the word "Battery" somewhere in Subject field to insure that your e-mail will not be blocked by my spam filters. All e-mail received with a virus, spam or a worm will be unread and automatically deleted. For questions, errors, omissions, comments, suggestions, or broken link notifications, please send e-mail to

I highly recommend that you hyperlink to rather than republishing any of these documents because the information is frequently updated to keep up with advancements in batteries and changes in the battery industry, resources, hyperlinks, telephone numbers, etc. Revisions will be indicated with more recent date. These documents are in the public domain and can be freely reproduced or distributed without permission subject to the "fair use" restrictions below. Attribution is always kindly appreciated, but not required.

The Car Battery FAQ was first published on the Internet on June 24, 1995 and the Deep Cycle Battery FAQ on October 24, 2003. The two FAQs were combined into the Car and Deep Cycle Battery FAQ on April 9, 2004.

Fair Use Notice

This Website may contain copyrighted material the use of which has not always been specifically authorized by the copyright owner. I am making such material available in my efforts to advance understanding of educational, economic, and scientific issues, etc., of lead-acid batteries and not for profit. Attribution is given wherever known. This constitutes a "Fair Use" of any such copyrighted material as provided for in Section 107 of the United States Copyright Act of 1976. In accordance with Title 17 U.S.C. Section 107, the material on this website is distributed without profit to those who have expressed a prior interest in receiving the included information for nonprofit educational purposes. For more information, please see: If you use copyrighted material from this website for purposes that go beyond "Fair Use", you must obtain permission directly from the copyright owner.

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