New Grass Trimmer Goes Lithium Ion Power!

[sikeston34m]

Troy Bilt just came out with a new electric trimmer.

http://www.lowes.com/pd_110523-65481-TB57_4294857347_4294937087?productId=3006629&pl=1&currentURL=/pl_String%2BTrimmers_4294857347_4294937087_?rpp=15 $No=15

Of course, I had to run down and get one.

It's pretty powerful and easy to use. It's not as powerful as a gas trimmer, but starts much easier than one of them.

The charger seems pretty smart with Red and Green leds indicating charging or not. Charge time is a bit slow IMO. At 4.5 hours of charge time, I believe it to be charging at around 1.3 amps.

I haven't taken apart the head unit yet, but it appears to be a really powerful brushed motor. It spins the head at 8000 rpms and does cut through pretty thick stuff with ease.

The trigger is variable speed, but does have an overly stiff return spring.

The Lithium Ion Pack is what interested me the most. Advertised at 20 volts and 6000mah, it does pack some electrons.

Of course, I had to take the pack apart.

As I finally got out the last screw, I was expecting to find a number of 18650 cells inside. Or perhaps some soft Lipo cells.

Much to my surprise, I found neither!

Housed inside the tough plastic casing is 5 of the largest Lithium Ion Prismatic cells I've ever seen.

They are arranged in a 5S pattern with a Battery Management Circuit.

There is also an "in the pack" battery fuel gauge. 4 Led's tell 25%, 50%, 75%, and 100% Charge.

The Management circuit is connected to each cell via what looks like a balancing lead. This leads me to believe it does perform the balance function.

I did run it completely down to check for a LVC. The LVC is present and hard cuts at 3.2 volts per cell.

The charger charges to a conservative level of 20.60 volts.

While I had the pack apart, I couldn't resist the opportunity to solder in a quick charge lead. This will allow me to quick charge with my Superbrain in about an hour.