Quick chargers?
- Thread starter ki11a
- Start date
indianajo
Well-Known Member
There are 6 amp & 4 amp chargers for bigger batteries. If you read the cell datasheets, there is a max charge current. Multiply that rating by 14 for my 17.5 ah 14 stack battery.
I've been charging mine at 4 amps with a charger I built out of surplus parts. Slows down above 80% though as it's driven by a 45 vac transformer, not a CCS.
I've been charging mine at 4 amps with a charger I built out of surplus parts. Slows down above 80% though as it's driven by a 45 vac transformer, not a CCS.
Sierratim
Well-Known Member
- Region
- USA
- City
- Nevada City, CA & Paradise Valley, AZ
I suppose 'quick' is a relative term. Many ebikes come with 2A chargers. My has a 4A as standard. Faster, but still, you can't fully charge a low battery at a lunch break. The Grin Satiator programmable charger, https://www.ebikes.ca/product-info/cycle-satiator.html, can go as high as 15A on 36V battery packs. The issue becomes how much charging current your battery pack can actually take without damaging the cells. Some battery manufacturers publish these specs. Many ebike manufacturers do not. So unless you can confirm the max charging current for your battery it becomes a buyer beware issue. With that said, you can estimate the max charge current for your battery pack based on its storage capacity divided by its voltage times a 'C' factor of 0.5 - 1.0, depending on cell quality. To use a 36V 500Wh pack as an example, 500/36=13.9 x(0.5 or 1.0). Let's use a 'C' factor of 0.5 to be conservative. This yields a safe charge current of 7A. I personally would be OK with this for a name brand battery pack.
This article at Battery University has some good insights into charger tech and ultrafast chargers; https://batteryuniversity.com/learn/article/what_everyone_should_know_about_battery_chargers . Their point is that ultrafast chargers exist for batteries designed for this tech. They can reduce wait times for charging, but at the expense of battery life. They recommend using ultrafast charging sparingly, even when the battery is designed for this.
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