Chargers that can charge at more than 10A / 2C? What do you use?

[BrianG]

Someone did some testing at >2C charge rates and noticed you don't gain a whole lot of time. It seems that the battery hits the CV threshold much much sooner and it stays at the CV stage longer. So while you do gain some time, it's not as much as you'd think.

Then, charging 5Ah packs at 5C is 25A! 4s at 25A will take a max of 420w! At some point, the only equipment capable of that level of power/current will be bench CC/CV power supplies, but they don't have all the error checking and balancing functions that true chargers do. Manufacturers are gonna have to start making chargers run directly off 120v with built-in high voltage switching power supplies to deliver that kind of performance. It's just getting too high for 12v. To get 420w out of 12v, you'd need around a 45-50A supply. Not cheap.

[krashkrieg]

Originally Posted by BrianG

Someone did some testing at >2C charge rates and noticed you don't gain a whole lot of time. It seems that the battery hits the CV threshold much much sooner and it stays at the CV stage longer. So while you do gain some time, it's not as much as you'd think.

Then, charging 5Ah packs at 5C is 25A! 4s at 25A will take a max of 420w! At some point, the only equipment capable of that level of power/current will be bench CC/CV power supplies, but they don't have all the error checking and balancing functions that true chargers do. Manufacturers are gonna have to start making chargers run directly off 120v with built-in high voltage switching power supplies to deliver that kind of performance. It's just getting too high for 12v. To get 420w out of 12v, you'd need around a 45-50A supply. Not cheap.

+1

I use an Ofna 30 amp PS for my Hyperion Duo3
http://www.horizonhobby.com/Products...rodID=OFN92136

I charge my Gx3's 6500 at 2.3C (about 15amp ea) and it takes 20-25 min for a full charge from an LVC of 3.3/cell!
My 5000mah Tenergy's take 3C charge rate full charge in 20 min.

If you really need faster than that you need to have more batteries...

[johnrobholmes]

Originally Posted by BrianG

...4s at 25A will take a max of 420w! At some point, the only equipment capable of that level of power/current will be bench CC/CV power supplies, but they don't have all the error checking and balancing functions that true chargers do. ....To get 420w out of 12v, you'd need around a 45-50A supply. Not cheap.

Yep. The Ebike guys are starting to use CCCV bench power supplies with standalone balancers like the battery medic from HC. With 12 to 20s setups and 10 or 20a/h packs we need it just to get a charge below 4 hours.