Help to choose the right BMS for my escooter repair

F

fjodorlogin

1 mW
Joined
Aug 13, 2021
Messages
16
48v 25ah 13s10p 500w

People have recommended the Daly BMS in my previous post (links to BMS and previous post👇)

How should I go about finding out how many amps I need?

https://m.aliexpress.com/item/4000812224182.html?spm=a2g0n.productlist.0.0.42c1aYSSaYSSyz&browser_id=ad414d1b295d4fedaed66c6abbe14bbe&aff_trace_key=c1b147c16c714acd9b070d3f17ff8da3-1654385730063-04103-_dXdw8xt&aff_platform=msite&m_page_id=u3ppgosymiucavdf181313794202240bddcc1f6142&gclid=&pdp_npi=2%40dis%21EUR%21%2117.46%2117.46%21%2110.55%21%21%402101e9d316543881352877236e7943%21%21sea&algo_pvid=e0dca3c9-f5ed-4e1d-b25a-683df6e49e69

https://endless-sphere.com/forums/viewtopic.php?f=35&t=116291
 
Don't get your panties in a twist. I reported it so it could be thrown in the bin, no need to fill the world with crap, right?

In one thread you got a lot of help here. Then you decide to open a few more with just cross references. Makes me wonder if you're a bit older and not so used to digital media? If so then i can tell you that it's better to post stuff that actually contains some information, or post a question that can be answered. That's what forums are for, OK?
 
Moderators,

Please delete this post since I am unable to do so(?)

I did not know crossposting in this forum is banned (I am a new user)

Maybe also put the "general guidelines" a bit more visible for folks like me! =)


larsb,

I am completely calm and have not needed to use any CAPS so far (unlike you)

If anybodys panties are a bit bunched up its yours, please explain calmly next time what you consider against the rules/illegal before reporting!
 
fjodorlogin said:
48v 25ah 13s10p 500w

People have recommended the Daly BMS in my previous post (links to BMS and previous post👇)

How should I go about finding out how many amps I need?
Click to expand...
This is a common/frequent question. Here is a typical thread that helps explain the importance of knowing the 'limiting current' of your Controller before you can determine the proper amperage rating of the BMS ... https://endless-sphere.com/forums/viewtopic.php?t=92168 ... Here's one reply ...
the controller will likely be a 36v 17A and the motor a 36V350W geared front hub motor. From what I understand from your post, the 35A BMS I have should be ok since the controller will never attempt to draw more than 17A anyway?
Click to expand...

You have not told us the limiting current of your Controller. The Controller rated Amp drain determines the size of the BMS amp rating. If the Controller limit rating is 20amp then a 30A BMS should be sufficient. If the Controllers' current limit rating is 30amp then a 40A BMS should be sufficient. The extra BMS amp rating is an extra safety buffer (just in case).

In the above example the 36V, 35A BMS is twice that of the 36V, 17A Controller -- :thumb:

The difference in cost between a 30A BMS and 40A BMS is only a few dollars.

DALY 13S 30A BMS ... https://www.amazon.com/DALY-Battery-Management-Protection-Balance/dp/B0876NQ88P/ref=sr_1_3?keywords=13S+48V+BMS+DALY&qid=1654457486&sr=8-3 ... $18.90
DALY 13S 40A BMS ... https://www.amazon.com/DALY-Battery-Management-Protection-Balance/dp/B0876NGKLZ/ref=sr_1_3?crid=1G7X7H3UK5F2T&keywords=13S%2B48V%2B40A%2BBMS%2BDALY&qid=1654457718&sprefix=13s%2B48v%2B40a%2B%2Caps%2C148&sr=8-3&th=1 ... $22.88
 
Thank you for clarifying!

My controller unfortunately lacks any identifiable text.

The guy from the thread you posted got this answer:

""I'm still trying to understand battery packs and I was wondering what is the Amp for a 10S4P battery pack built with Panasonic
NCR18650PF 2900mAh - 10A batteries? 40A since there are 4 in parallel?"

"Basically, yes. It's a question that's been answered a lot (and even asked already by you in your first post), so it doesn't
need it's own thread.""

This logic does not quite make sense to me since it would mean my old BMS would have been around 100amps..

Upon closer inspection I noticed I only have 80 cells left of 130 so my plan is to change the configuration from 13s10p to 13s6p
 
I took apart my old BMS which had four of these transistors

https://www.lcsc.com/product-detail/New-Arrivals_CRMICRO-CRSS052N08N_C410924.html

Unfortunately I could not find any answers to whether these transistors could reveal the size of my old BMS.

Most of the controllers I find online when I Google "48v 500w escooter controller" are between 20-30a so I think I might just order the 40a daly BMS and call it a day.

Thanks again for your help! :thumb:
 
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