Ancheer Battery 36V - Balance Charger integrated? How does it look inside?

[Philippp]

Good evening and hello,

first of all, thank you for having me - this is my first post, still as a non e-bike owner. However, I am about to change that and hope that you can help me with your expertise.

I would like to buy an Ancheer foldable mountainbike for my wife and myself; for now, we are the occasional bikers and this seems like a good option to explore whether we want to go serious with this hobby.

However, I have some question marks regarding the battery. I know Lipos and Liions from my RC hobby, and I make storage/ charging saftety a top priority. Looking at this battery:

Replaceable lithium battery 36V, 8AH For ANCHEER AM004143 Upgraded Version

Note: E-bike batteries destined for USA and Europe are shipped from Chinese warehouses, customers pay import duties. Buy Ancheer Original Battery Charger US/EU/UK Plug Click to view the bicycle corresponding to the replacement battery Weight 3.5 KG Dimension 28*30*10(CM) Rated Voltage 36V Rated...

www.ancheer.shop

I only see two cables, one being an XT60 port, the other one also looking like only being a lead and ground wire. Now for 36V, the battery will likely be made of standard 18650 cells, 10 in a row, or in other words a 10s battery. In my RC hobby we praise to ALWAYS balance charge your batteries, to ensure that every cell has the same voltage and thus can discharge at the (roughly) same speed to the (roughly) same end voltage. We do that to avoid cell damage (below end voltage) and ultimately to avoid killing your battery. So far so good.

Now, on all images that I can find I only see these two cables, but am missing the balancer cable. The only explanation (besides Ancheer simply not balance charging the battery, which would lead to a few garages burned down) I can have is that there is some sort of balance charger integrated into the battery itself.

Long story short - Is there any one that can shed some light on that topic before I go out and buy?

Thank you very much in advance! Stay safe, and best regards from Vienna.
Philipp

 

[harryS]

Here's a schematic for a typical ebike battery management system (BMS). All halfway decent batteries have a BMS.

The X2 circuit controls discharge from the battery. It usually monitors each series group for undervoltage, shutting off if any group goes below a minimum cell voltage. It also shuts off for over current. Well, it should shut off.

The X4 circuit controls charging, shutting off when any group exceeds the maximum cell voltage. Some of the better ones will do limited cell balancing, bleeding off voltage from a group and allowing any lower voltage groups to continue charging.

We call them balance wires ... but I think that most inexpensive ebike batteries don't balance. Sometimes I buy BMS boards with balance circuits, and I swap them in.

You can charge a battery the the discharge connector, but there's no overvoltage protection, and if the charger voltage is too high, you run the risk of ruining the battery and a fire. I ruined a good battery last year doing that, Lucky, no fire.

There are also some BMS circuits which combine the charge and discharge connectors into one single connector. You'll have all the safety functions still available. Probably won't find them on an ebike battery.

 

[Philippp]

Wow, you elaborated like I never expected - thank you very much! So I take away that there is some balancing going on, at least for the grouped cells, but one cannot guarantee that Ancheer Batteries do indeed do so. Probably will then go for a medium ranged bike instead. Do not want to start a fire/ it does not make sense to store my 1.3a 4s batteries in a fire retardant box AND a safe, then have the cheapest battery in the house on my bike.

Thank you again, harryS!