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 amazon.com; 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:
Since you now have an 18 ah battery instead of a 22 ah one, do you notice a difference in how much grass you can cut per charge? I have the CMM1000 green lawn mower type 1 or 2 with a B&D 17ah battery and about 5000 sq feet of fairly thick grass to cut (some areas are so thick it actually slows the motor down a bit) and I find that I have to split the cutting job over two days. I bought my son a universal 22 ah battery (two) and installed it for him. He can do front and back on a single charge and still have a lot of green on the battery meter. He's only been using it for about 6 weeks.
ReplyDeleteMark,
ReplyDeleteConcerning the UB12180 battery, I find that the OEM battery by B.B. Battery, model BP17-12, has a much longer run time as it ages, and the service life is about twice as long. The Gruber Power battery I tried was also inferior to the B.B.
I'm looking at the Shorai lithium motorcycle batteries. The 18 Ah equivalent LFX18A1-BS12 weighs 2.12 lbs, versus 13.56 lbs for each of our lead batteries. Too bad they cost three times as much at $190 each. I asked Shorai which model they recommended for the B&D mowers, they said they do not have a battery for that application. I wonder how well the LFX18A1-BS12 would work.
Black and Decker makes Li-battery powered trimmers, chain saws, leaf blowers, etc, but so far no mowers. I think the battery costs are still too high for the mowers to reach mass-market sales numbers. For instance, the Bosch Rotak 43 LI mower is available in the States this year for $500 from fruugo.us, but with a feeble 36 V, 2.6 Ah battery. That works out to 94 Wh, compared to our battery packs at 408 Wh. Spare Bosch batteries cost a whopping $300! The Bosch 36 V 4.5 Ah batteries are not available yet AFAIK.
Paul~
Really appreciate this post. It’s hard to sort the good from the bad sometimes, but I think you’ve nailed it!
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