User:Bfoley/wheelchair

Write problem/project Goal
Advance the wheelchair project. First off: Test parts to see function.

My First Task
Get familiar with the project's advancements up to this point.

Summary of actual work over first weekend
Took notes from the last team's pages.

Week1 Narrative
When I took a look at the last team's team page, they had not yet pulled everything together. I was chomping at the bit and so I took a look at the individual pages while they were pulling everything together. On Thiam's page, there is a link to the wheelchair's schematics. Onzere has more information for the wheelchair. I was intending to get a look at the physical presence of the the wheelchair, but I never made it in to HCC.

My Second Task
Because I missed a week of school and did not get in contact with my team members, I was unable to negotiate a second task.

Week2 Activities
No progress was made over the weekend. Once I had returned to class, I stepped up to work with the batteries.

Week2 Narrative
October 23rd was my return to class. I checked in with my teammates and took on working with the batteries. Most of the warnings suggest using official and professionally manufactured parts when dealing with the batteries. Because I am not proficient in this area, I believe heeding the warnings will save me from horrible injuries and, as an added bonus, keep these expensive batteries relatively usable. Three more wheelchair batteries were donated to HCC. Because these and the original batteries might not be connected properly, charging might damage the charger and "usage in an introductory engineering class" would not be covered by the warranty. Another power source would need to be found. After extensive search online, many chargers that are specially designed for AGM batteries would cost upwards of $30. Budgets are incredibly important when completing engineering projects. After scavenging the lab, I found a charger that should work: the Thunder AC6 Dual Power charger. It has many settings for different types of batteries. http://www.invacare.com/cgi-bin/imhqprd/inv_catalog/prod_cat_detail.jsp?s=0&prodID=3GARBASE&catOID=-536887497 http://www.invacare.com/doc_files/97_188.pdf http://www.batterystuff.com/batteries/rv-marine/agm/8A22NF.html

My Third task
Continue figuring out the needs of the batteries, so that they do not explode or get otherwise destroyed while charging.

Week3 Narrative
After much searching, I have located data sheets on the various batteries in our possession. They are as follows: 1 Universal, 2 Interstate, and 2 MK Powered. This allows those working on the project to know the limitations of each battery. I labeled the duplicate batteries so that I could be aware of which battery was which. The MK Powered models are A and B, while the Interstate models are Ω and Σ. Then I took the charges of each to see what I would need to do to charge: A read at 12.63V, B 12.61V, Universal held 13.17V, Σ had 3.75V, and Ω 4.82V.

http://upgi.com/Themes/leanandgreen/images/UPG/ProductDownloads/45825.pdf http://www.enalmex.com/docpdf/baterias/interestate/dcs_75bt.pdf http://hota-exp.com/UploadFile/Download/2011071211005065.pdf

My Fourth task
Work on documentation of the project, figure out why the Interstate batteries won't charge.

Summary of actual work over fourth weekend
Most of the work was done in class rather than over the weekend. Not much headway was made on documentation.

Week4 Narrative
At this point, I am willing to declare the two Interstate batteries completely dead. Many batteries are unable to return to service after draining to 10.5 volts. Ω and Σ are well below that. There are some methods to reviving batteries, but none of these methods are suitable for use at HCC. The Universal and MK Powered batteries should be adequate at this time. The battery terminal caps were designed to enclose rounded SAE posts. The metal used for the terminals were fairly malleable, which would lead to the terminal caps to become stuck in place or retain their shape. The MK and Universal models are equipped with T881 posts and are too big for the terminal caps. I sawed off one side of the cap so that the bolt could be threaded through the cap and the post to create a connection that can be removed as needed. My tutorial on how to change the batteries in the casing. Basic battery glossary for easy reference. Most of the terms are Layman's, rather than official, for an easy starting place.

Complete Team Page
Team Page