Worx WA3578 - PowerShare 20V 4.0Ah, Lithium Ion High Capacity Battery, Orange and Black

Lasts for almost an hour with my Worx chainsaw. Charges pretty fast and has unstoppable power.

Super duradera y carga gapida

Good battery for my worx tools last long on every charge.

For 20V and 4Ah, it's supposed to be 80Wh, however it states 72 Wh on the label. That's a 10% haircut. I understand battery needs a bit head room to not get overcharged but manufacturers should not transfer this cost to customers.

It has a lot more capacity than the smaller 2 Ah ones. Plus when you are done, and want to recharge it, you don't get the red light which means wait an hour until it cools down. It takes a new charge right after using up the first charge, no red light. I have 2 of the 4 Ah ones now for my several Worx tools, including a chainsaw.

I have a Worx string trimmer that came with a 2AH battery. That original battery always ran out about 80% through using it. This 4AH battery easily lasts the entire job, and I still have the 2AH one in reserve. It seems to be a pretty well-made pack, and the cells inside are hopefully quality and long-lifetime.It was pretty expensive, but that's the way these power tool companies work now. Cheap tools, expensive batteries.SPECIAL NOTE: I tried a cheap "6AH" Chinese knock-off no-name battery before I bought the name-brand one, and it wouldn't even charge with the official charger. When I took it apart and tested the 18650 batteries inside the knockoff Chinese battery, they corresponded to an overall battery pack that had about 2.5AH (not 6AH), so even if it had worked, it wouldn't have been worth the price, as it was about the price of a 2 or 3AH battery. Also, the reason it wouldn't charge was that the battery management system board was dead on arrival. Long story short, I do NOT recommend buying the knockoffs. They overstate their capacity, they use mediocre cells, the electronics in them are cheap and unreliable, and they are probably dangerous as a result. If you are strapped for cash, you might as well just buy the name-brand in a "lower" capacity.

And ready to store more for your convenient use. I have about decided that this battery is about all the work I want to do with a WORX tool - in this case a chainsaw. By the time this battery gives out, so am I and it's time to quit anyway. Since they have a variety of battery capacities, base the size you buy (2A, 4A, 6A, etc.) on your age and the amount of time you want to work. That way, when you flop out in the easy chair after a round of yardwork you can tell the wife "I worked until the battery ran out.... it's recharging!" and you can recharge with cold adult beverage with a true metric to judge your work by. Inescapable logic! Just don't let you wife be ordering any extra batteries or that high speed charger thingy they sell. If you convert all your yard equipment over to WORX you can even use it as a bargaining tool! "Honey, I'm gona weedeat the yard until the battery runs out, then I have to call it....." You can tell your buddies at 1:00pm, "Hey, I gotta weedeat the yard first and the battery lasts about 45 minutes, so I can make that 2:00 pm tee time!"Thanx Worx!

The 4A WA3578 battery is just what the doctor ordered for my Worx tiny chainsaw. It came with a 2A battery: OK for very small jobs but ran out of juice after about half an hour of cutting and dragging away fallen branches. With a lot of tree damage last winter half hour barely made a dent before hours of charging (slow charger that came with my saw).With the addition of this 4A battery I keep going for an hour and a half before I have to start recharging again. By then I'm happy to take a break. EXCELLENT!It is (no surprise) about twice as heavy as the 2A battery, but Worx did a good job with my little chain saw. Even with the battery it maintains good balance. Nice design.I thought about going with a 3rd party 4A battery, but decided to stick with the brand name. Just want it to be dependable and compatibleEven with my slow charger this 4A battery has exceeded my expectations. I'm giving a hearty 5 stars.