The devices that get advertised with higher battery voltage are not better just because of that. The point of higher voltage is to achieve lower current, which means the manufacturer can use thinner cables. These cables need a bit more insulation, but plastic is way cheaper than copper.
Same for the plug, the design is most likely based on economics rather than usefulness with the intent to break after warranty is over while making 'official' repair cost prohibitve. The point is that customers go and buy something new.
Good info, William. I had no idea gas mowers lasted longer than electric mowers. In my experience, it's been the opposite. As for the cord, after many years of using electric mowers, I never found that the cord was a problem. These days I have a small yard, so I'm back to the days of my youth with a push mower. It's a simple and lovely contraption.
You're right William. I still use a cordless mower and there are some real issues with the batteries. They unit came with SLA cells, which are heavy and only last about four years. I'm on my third pack now and have switched to NiMh since that technology can now pack a little bigger punch when the starting current is over 30A. I have a 10AH, 20 D cell, which is 10 lbs lighter than the 17AH SLA cells and has about the same run time. If you can believe the specs., I should get a few more years out of these cells. I toyed with going to LiFePo, but the cost is still very high on those cells, so maybe next time.
It's pretty easy to gauge the State Of Charge on SLAs and the original electronics in the mower did this pretty well, but it is impossible to do an SOC on NiMh cells. I removed the original electronics for charging and designed a little solar charger, so now I have a green mower. It takes about three sunny days for a full charge and I have never had to supplement the solar charge, but if I were to do it again I would get a corded mower.
I recently worked on a cordless mower and it is clear that the first design priority is minimum cost to build the thing, followed closely by a willingness to give up quality and usability to assure that even the most determined fool will have a hard time getting hurt on thr mower. It was not possible to check charge state while charging, and it was very inconvenient to disconnect the charging cord to enable readings.
That is why I continue to use electric mowers with a power cord. They don't last as long as the older gas engine units used to last, but I think that eight years average for a used mower is OK. They take less maintenance, once the starting interlock is removed, and they are always ready to use, never dead batteries.
The trick is to use an orange cord with the mower, and to never run the mower over the cord. Avoiding the cord is jalmost as simple as always avoiding ones toes. I do wear cords and mowers out, but don't break them.
I am curious about the model # of the trimmers that have problems. I bought a new Black & Decker 18V "Grasshog" trimmer last year and am very happy with it.
The battery slides onto the bottom of the top end of the handle and counter balances the motor on the other end. Since you remove the battery and clip the charger directly to it, you can charge one while you use one as long as you have a spare. Since My trimmer came with 2 batteries, and the drill also came with the same battery, I'm all set.
It shares the batteries with my Drill of the same make. 3 Batteries, 2 chargers, no waiting. (OK one of the chargers plugs direct into the drill, so it's for after use)
This is not the most powerful trimmer or drill, but it works fine for me.
Uniquity, I too have had trouble with line trimmers. The device that gives you more line when you bang it on the ground seems to always fail for me. Then I'm stuck turning it upside down, pushing on the part you bang on the ground and trying to pull more line out. You need three hands to do it right.
I recently bought a 35cc gas trimmer and noticed it goes through trim line really quick and I know I don't go through that much since my other trimmer allowed me to trim for hours on the same feed. Anyway.. you can soak the line in water to make it less brittle and have noticed that reducing the engine speed on this new trimmer seems to really help conserve string.
I think I see your complaint. Why would you make a safety switch out of the electrical terminal that also charges the unit when your not even supose to pull plugs by the cord to disconnect them from the wall plug. Obviously the plastic molding is lacking when legos can be molded with more accuracy than something that could do some harm to a person. I bet those prongs are tiny too.
In a bid to boost the viability of lithium-based electric car batteries, a team at Lawrence Berkeley National Laboratory has developed a chemistry that could possibly double an EV’s driving range while cutting its battery cost in half.
Using Siemens NX software, a team of engineering students from the University of Michigan built an electric vehicle and raced in the 2013 Bridgestone World Solar Challenge. One of those students blogged for Design News throughout the race.
Robots that walk have come a long way from simple barebones walking machines or pairs of legs without an upper body and head. Much of the research these days focuses on making more humanoid robots. But they are not all created equal.
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This discussion will examine what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.