BMS and Protected Battery

Hi,

I'm asking what is the difference between BMS and Protected Battery.

If I buy protected battery, I have to install, in a DIY battery pack, also the BMS.

Hope this question is not too silly!

Thanks

Mark

I think the main difference would be written in English, or machine translated to English.

A battery with a bms, would be a protected battery. So my assumption would be that a protected battery would have some kind of bms.

But if they won't tell you the bms specifications, they wouldn't get a dime from me.

if you don't understand about batteries and have no need to learn it would be better to buy a pack already assembled and not DIY. if you buy a pack that is manufactured it will have a BMS installed already. except for the RC lipo packs.

Here is a link http://www.lygte-info.dk/info/battery protection UK.html

I suspect the question was more around if he was to use protected 18650 cells would he still need a BMS for the whole battery.

Do NOT use protected cells for a ebike battery. They aren't suitable. And a good BMS on the pack is a better choice.

Edit: just clicked on Falcos link, looks like he thinks 18650 too.

Thank you all,

I try to learn better for school porpouse and my personal interest.
In a few months I'll build one with my teacher and I want to be ready.

Why protected battery aren't suitable?
How can I choose the right BMS if I've got a 48v 20 ah? I don't know how to calculate.
Can you suggest me which one is good (a brand or where to buy)?
Is there any tutorial that can explain how to or theory?


Mark

Should have goggle searched it before I spewed an ignorant comment.

I hadn't heard of cells with an individual bms inside. But here is a diagram of one.
http://www.lygte-info.dk/info/battery%20protection%20UK.html

So for a larger pack, yes, you would want to use unprotected cells. Then you can string them in parallel groups, then use a bms for low voltage cutoff of the groups, each of which will then behave like one larger cell.

Those protected cells look good for some applications, like a flashlight or camera. But not for building a larger pack.

Hi,

I think my battery pack is going to die soon and I want to build a 10s4p pack out of Panasonic blazar 3400mAh 18650 cells (40 of them..). These cells are individually protected so does this mean I can avoid a bms for the whole pack and simply rely on the IC in each cell? Using a 42v charger. I have seen the replies where this is not recommended but nobody says why?? It would greatly simplify diy battery pack construction. Regards,

Matt