Are eBike Chargers "Smart"...Mine Apparently Isn't

[arcom]

I was reading the "battery tips" blog for DJ Bikes when I came across this recommendation:

"....it is highly recommended you stop charging the battery immediately the battery is full (100%). If you continue to charge the battery when the maximum battery level has been attained, please note this leads to over-charging at elevated temperatures, and may result in internal lithium metal plating accelerated by a lasting loss in capacity. In lame man’s language, it causes irreparable damage to your battery. "

I may be mistaken, but that sounds to me like the charger does not sense when the battery reaches 100% and will continue applying full power to the already 100% charged battery , just the opposite of what I understand a smart charger to be. Is my charger common for ebike charging systems or unique to DJ Bikes?
TIA

Here's the details of the battery and charger

 

[Dallant]

FWIW, my Bosch charger shuts off when the battery is charged. Seems smart enough to me.

 

[harryS]

Causes irreparable damage to the stuff around the battery too,

A couple of general thoughts though. A properly designed battery will shut off charging when any of the internal cells reaches the maximum safe voltage. Even a cheap lithiunm charger will shut off when it sees the battery at max voltage, Therefore, you have two independent safeties to protect against overcharge,

Nonetheless, I agree that it's best to unplug the charger when it is finished charging. If the cheap charger fails, then you only have the battery safety circuit.

 

[CdnShaun]

Does your battery have a BMS controller? Many do and it regulates the charging process, cuts off the charger (stops drawing in charge) when it reaches full.

What you will see in choices you have for chargers are smart models that can stop at 'less than 100%' of the battery. A battery's built in BMS almost always will charge to 100% (then cut off the charging) since it's how they were designed - they do not come with a 90%, 80%, etc control system (i.e. a switch).

With chargers that can charge up to say 90% they cut off before the battery BMS does. For example my 52V nominal battery will charge to 58.8V as a 'full charge' and the BMS will shutoff. The charger I have for it has a manual switch between 90% and 100% - so it too will stop at 58.8V when set to 100% (double protection) but will stop at 57.4V when I flip it to the 90% setting. This helps extend the life cycles of the battery as well documented in multiple threads here on EBR.

The smartest chargers I have come across are the Grin Technologies Satiator's. You program them with the profile of your battery (Volts, chemistry/type, etc) and then can control the charging level to the percentage or voltage level you want in fine detail. Expensive yes, but very cool.

Chargers - Ebike Parts - Shop

All of our battery chargers are CE and (c)UL certified, sealed, fan-free, and terminated with either ST3 or XLR charge plugs. We have both dedicated chargers for specific voltage batteries, as well as our <a href="/product-info/grin-products/cycle-satiator.html">universal Satiator charger</a>...

www.ebikes.ca

Reading your post again my guess is your 13Ah battery pack has a BMS within and is what controls/limits/regulates the charging process for safety regardless of what charger you connect to it.

Let us know what you find out.

 

[Alex M]

I was reading the "battery tips" blog for DJ Bikes when I came across this recommendation:

"....it is highly recommended you stop charging the battery immediately the battery is full (100%). If you continue to charge the battery when the maximum battery level has been attained, please note this leads to over-charging at elevated temperatures, and may result in internal lithium metal plating accelerated by a lasting loss in capacity. In lame man’s language, it causes irreparable damage to your battery. "

..... Is my charger common for ebike charging systems or unique to DJ Bikes?

Yes, common. BMS will stop the charging when battery is overheated, who knows how long it will take to do this, you don't want it to heat when not necessary, so better unplug.
"Irreparable damage" is a strong language. It likely won't die or irreversibly lose half of its capacity after sitting at 100% for half an hour, but any heat shortens the battery life.

Also, charging it every time to 100% will shorten its lifespan. It's better to charge it to 90%, and let it charge to 100% once in a while - once a month maybe. Most chargers are not smart enough to do 90%, the cheapest option is to use a timer. Or buy Luna charger, it has a switch 80-90-100. Or Grin Satiator if you really have lots of money.