Saturday, July 16, 2011

Another new battery

Table of Contents

Note: if you have a question to ask, please ask it at Lawn Mower Forum, either in the Black & Decker area or the Electric & Battery Operated area at that website. I apologize for being unable to handle individual requests for help posted on this blog or sent by email.
Important: always use sealed lead acid batteries for your lawnmower, as they are spillproof.

A couple weeks ago I replaced the mower batteries, two years after their last replacement.  The two-year lifetime of the model TR22-12 battery from Tempest was dissappointing, but maybe not surprising when I think about it.  The higher charge capacity (22 Amp-hours, vs. 17 to 18 A-hr for the original battery), in the same overall battery volume, may have come at the expense of a shorter battery lifetime as a matter of design.  A more technical discussion can be found at Physics Forums.

This time around, I ordered two new 12V, 18 A-hr batteries from; they are model UB12180 made by Universal Battery (or maybe it's Universal Power Group?  It is difficult to tell which).  The total cost was $94, which included two-day shipping; I wanted them quickly, before I had to mow again.  It looks like the price with standard shipping would have been $82.

One thing to know, if you order these batteries, is that the connections are made slightly differently than in the battery that came with the mower.  These batteries have tabs (below, top) instead of built-in threaded holes (below, bottom):

Not a big deal, except that I had to bend the tabs back, about 45 degrees, on the connecting cables in order to reduce the stress placed on the cables and connections:

After connecting cables to the 4 battery terminals, securing the battery strap, and replacing the two foam blocks I was good to go: