Why use a fuse on a pack?

Batteries, Chargers, and Battery Management Systems.
Post Reply
User avatar
rg12   100 kW

100 kW
Posts: 1048
Joined: Jul 26 2014 4:22pm

Why use a fuse on a pack?

Post by rg12 » Jan 24 2017 6:31pm

Hey Guys,

Why do ebike battery packs which have a BMS inside (with a max amp circuit breaker in it) need a fuse?
all of those standard silver fish cases have a fuse in them in addition to the BMS.
24S 17.5Ah 25R, Greentime Controller, QS203 5KW

User avatar
fechter   100 GW

100 GW
Posts: 14162
Joined: Dec 31 2006 3:23pm
Location: California Bay Area, USA

Re: Why use a fuse on a pack?

Post by fechter » Jan 24 2017 10:43pm

BMS can fail. It's one of the most likely things to fail. Fuses are cheap.
"One test is worth a thousand opinions"

User avatar
Inwo   10 kW

10 kW
Posts: 603
Joined: Dec 13 2016 12:01pm
Location: SE MN. USA

Re: Why use a fuse on a pack?

Post by Inwo » Jan 24 2017 11:23pm

Is there a like button on this forum?

markz   100 GW

100 GW
Posts: 7546
Joined: Jan 09 2014 11:38pm
Location: Alberta Canada

Re: Why use a fuse on a pack?

Post by markz » Jan 24 2017 11:38pm

Inwo wrote:Is there a like button on this forum?
No but Linus Tech Tips does

User avatar
fechter   100 GW

100 GW
Posts: 14162
Joined: Dec 31 2006 3:23pm
Location: California Bay Area, USA

Re: Why use a fuse on a pack?

Post by fechter » Jan 25 2017 8:56am

I'm hoping the next version of forum software has some kind of rating system. It's being worked on.... slowly.
"One test is worth a thousand opinions"

rguy56   100 W

100 W
Posts: 212
Joined: Aug 04 2008 8:06pm
Location: Winnipeg Manitoba

Re: Why use a fuse on a pack?

Post by rguy56 » Jan 25 2017 4:54pm

I've always used a breaker. That way I can use it as a switch to take up the energizing spark in the place of the connectors.

...besides it being there as a "back up". It has tripped.

User avatar
tomjasz   10 GW

10 GW
Posts: 4100
Joined: Mar 29 2014 1:45pm
Location: Out riding, MN USA
Contact:

Re: Why use a fuse on a pack?

Post by tomjasz » Jan 26 2017 12:23am

fechter wrote:I'm hoping the next version of forum software has some kind of rating system. It's being worked on.... slowly.
Take a look at modernvespa.com They have a karma system.

http://modernvespa.com/forum/wiki-karma

Kinda like a like system but with bugs worked out so it is really difficult to stack and abuse. It works. Not just because I'm highly rated, but it does incourage better responses and behavior. It had two choice , good and bad. No doubt there was a lot of whimpering when first put in place but after 7 years it's reall effective. The battle here would be the silly idea that freedom of speech is somehow a right in forums and typically the biggest complainers were some of the nastiest posters. I could make a list,even though still a short timer of whom the loudest objections might come from.


Main Page

Recently Added
Recently Edited
Added By Me
Edited By Me

All Articles

Discussion Forum

FAQ: Post Ratings and Karma
Why do we need a ratings system?
As Modern Vespa has grown, the volume of posts has gone from a trickle to a deluge, and the moderator staff has a hard time staying on top of every topic. In fact, we've given up on being able to read every post. It just can't be done.

To help preserve Modern Vespa as the helpful community that we have always strived to make it, we now use a post rating system, very similar to the rating system used in the majority of large forum and comment systems on the internet. This system relies entirely on the votes of individual registered users, rating posts with a simple thumbs-up or thumbs down on the posts they find helpful or obnoxious, respectfully.

This system accomplishes a couple of things.

First and foremost, it helps us do a better job of finding the really good posts among the hundreds of thousands of posts we've accumulated here over the years. Computers are good at analyzing numbers, not content, and so we're relying on the large audience at Modern Vespa to help us quantify the good vs. the bad.

Second, we hope this system will curb obnoxious behavior and make users think twice about posting something inflammatory or insulting. If a user values their reputation here, then they might think twice about taking jabs at another user, or a political figure, or generally being less than civil.

Finally, we'd like to identify the really good users who accumulate high marks, as well as the really bad users who are incorrigible and either don't know or don't care that they're being perceived as obnoxious. We'd like to reward the good users. We'd like to get rid of the bad users, or otherwise limit their access to the features of this community.
How does it work?
Every post has a thumbs up and a thumbs down icon in the lower right-hand corner of the post. Click the thumbs up, and the thumb will turn green. Click the thumbs-down, and the thumb will turn red. You can change your mind at any time -- just click the button a second time and your vote will be removed. Click a different button and your post will be changed.

Each vote raises or lowers the rating of a given post, and helps us identify the helpful posts and also the obnoxious posts. In addition, each vote is tallied in the account of the user whose post is being rated, and over time these ratings accumulate into a karma score, or a measure of how helpful (or obnoxious) that user is.

Posts that are, on balance, not very negative or not very positive (i.e. close to zero) are shown as "neutral". Note that this doesn't necessarily mean that the post is a mix of positive and negative votes, although that's one possible reason for a post to be listed as "neutral". It really just means that it's not clear enough to call it one way or the other.

The same goes for a user's karma score. "Neutral" means that their score is close to zero, and could be a little positive or a little negative or a mixture of the two.

An "at a glance" indication of a user's karma can be made from either the mod target signs or the red circles beneath their avatar/username, the targets being positive and the red circles negative.
How many votes do I get?
As many as you want, with a couple of caveats. You can only rate a single post once. As mentioned earlier, clicking a vote button a second time will undo your previous vote. You can only rate a given user once per hour, twice per day, and four times per week. This is to prevent abuse.
My karma score is negative, and I think (user_x) has a grudge against me
While it is entirely possible that a given user has a grudge against you, it is unlikely that a single user is causing your score to be drastically negative all by themselves. As stated in the above section, there are some definite time limits on how often any single person can rate you.

If your karma score is considerably negative, it is quite likely that a lot of people are rating you negative. You should really consider being a little more helpful and a little less incendiary in your posts.
Why can't I start a new topic?
If your karma score is considerably negative, then the forum will prevent you from starting new topics. Sorry, that's the way it is. You should really consider replying to some topics with helpful answers and hope that someone will rate your posts positively.
I get negative ratings everytime I post. What gives?
There are two possible explanations for this:

1. Your posts are more obnoxious than you think
Text is a funny thing. It doesn't convey emotions the same way a face-to-face conversation or even a telephone call does. Choose your words carefully, and think about how they might be construed and the context in which you are speaking. You might think you're being funny, but that might not be apparent to everyone.

2. Your past is haunting you
It is entirely possible that you have accumulated enough people with grudges against you, based on past experience, that they will continue to rate you negatively no matter what you say. It's unlikely that a genuinely helpful post would garner a negative rating, so you should focus on what you can do to be helpful.

If they continue to rate you down regardless, you've probably done something to deserve it. Sorry. Modern Vespa might not be the right place for you.

What does my bias rating mean?
Your bias is listed on your public profile page, and reflects the way you rate posts. If most of the ratings you give are negative, then your bias will say so. If you tend toward giving positive ratings, your bias will reflect that. If you give an approximately equal mix, your bias will be listed as "neutral".

Bias has nothing to do at all with the ratings you receive, only the ratings you give.
I'm new and I'm afraid if I post a dumb question I'll get rated negatively
You probably won't. We see almost no cases where a newbie is rated negatively for asking a question, even one that gets asked over and over. Mostly, the posts that are rated negatively are those that are, well, obnoxious. By "obnoxious" we mean insulting, degrading, spiteful, snarky, mean, prejudiced, superior, or arrogant.

If you just want to ask how to fill up your scooter with gas without it spilling all over the place, fire away.
I don't like my rating being shown publicly. Can I hide it?
No. The ratings are shown publicly as an incentive to be helpful and not act like a tool.
I'm a scooterboy and hate mods. I don't want a target, can I change it?
No. Get over it.
Last Updated Wed Mar 24, 2010 7:32 am
I'm
Thanks Justin_le we're here thanks to you. All the best to the mods for their tireless work keeping it on an even keel.

User avatar
tomjasz   10 GW

10 GW
Posts: 4100
Joined: Mar 29 2014 1:45pm
Location: Out riding, MN USA
Contact:

Re: Why use a fuse on a pack?

Post by tomjasz » Jan 26 2017 12:33am

Example of display members can access.
Attachments
IMG_1093.JPG
IMG_1093.JPG (92.48 KiB) Viewed 551 times
IMG_1091.JPG
IMG_1091.JPG (92.86 KiB) Viewed 551 times
IMG_1090.PNG
Thanks Justin_le we're here thanks to you. All the best to the mods for their tireless work keeping it on an even keel.

Post Reply