Is there a smart charger for DeWalt 20v MAX/Flexvolt batteries?

[K5lwq]

You should charge 100% every time you charge. If you are going to store for long periods at a time then discharge the pack about 20% or so.

Most smart chargers or fast chargers will use constant amperage until the pack is 80% to 90% then switch to constant voltage. This last 10% or so is when the chargers can balance the cells. Keeping a pack healthy is more about balance than how they are stored.

 

[LittleBill21]

I am going to drop this link here, hope some people will read it, but i have studied batteries for a while, the thought process is quite different then it use to be for batteries. li ion and lipo simply last longer if there are shallow DOD (dept of discharge), they also don't like being fully charged. the article below explains this in quite some detail.

How to Prolong Lithium-based Batteries - Battery University

"Most Li-ions charge to 4.20V/cell, and every reduction in peak charge voltage of 0.10V/cell is said to double the cycle life. For example, a lithium-ion cell charged to 4.20V/cell typically delivers 300–500 cycles. If charged to only 4.10V/cell, the life can be prolonged to 600–1,000 cycles; 4.0V/cell should deliver 1,200–2,000 and 3.90V/cell should provide 2,400–4,000 cycles"

I would read the article, it will change the way you think about batteries

"Exposing the battery to high temperature and dwelling in a full state-of-charge for an extended time can be more stressful than cycling. Table 3 demonstrates capacity loss as a function of temperature and SoC."

Also be aware that balancing depends on the charger, some balance on the charge side, some balance on the discharge side using bleed off resistors.

my drone uses pretty expensive lipo batteries, over 120 dollars each, the batterys by design automatically drops to 60% if not used for 7 days

https://dl.djicdn.com/downloads/mavic/Mavic+Pro+Intelligent+Flight+Battery+Safety+Guidelines-EN.pdf

page 5 under battery storage.

I hope this will clear up some confusion

tesla recommends between 50-90% charge.

Daily Life with the Tesla Model 3: Charging | It's Electric.

 

[rangerfredbob]

sorry, no fully charge is not correct, if you want longevity, battery manufactures recommend between 20-80% charge. multiple sources out there on this, even telsa i believe only charges to 80% or so unless you explicitly tell it to charger higher.

That's pretty much exactly what I said, or was trying to say... What I meant is it's better to leave it fully charged than leave it at the point the low voltage cutoff on the tool kicks in.

Doing everything "correctly" doesn't mean 100% success, there's still the luck of the draw, I have some lithium batteries from 2007 that still work to 80% of rated capacity, I had one drop one cell out of like 8 battery packs...