Search found 773 matches

by Nevilleh
Tue, 29 Jan 2013, 12:15
Forum: Batteries, charging, management and monitoring
Topic: Wanted - an amp hour meter
Replies: 69
Views: 11602

Wanted - an amp hour meter

I've decided to make 10 of these as that is the minimum number of pcbs that I can get from ITEAD, so if anyone else wants to buy a complete unit they will be available in about 10 days. Or the pcb only. Just send me PM with your details.
by Nevilleh
Mon, 28 Jan 2013, 21:03
Forum: Batteries, charging, management and monitoring
Topic: Wanted - an amp hour meter
Replies: 69
Views: 11602

Wanted - an amp hour meter

Oh, I was editing my last post when your new one arrived. Look back - hopefully not in anger!
by Nevilleh
Mon, 28 Jan 2013, 20:49
Forum: Batteries, charging, management and monitoring
Topic: Wanted - an amp hour meter
Replies: 69
Views: 11602

Wanted - an amp hour meter

If I pay you more, will you mount and bake everything for me? I have zero experience with SM stuff http://forums.aeva.asn.au/smileys/smiley6.gif Ah, you mean will I make one for you and sell it to you? Of course I will. How much money have you got? http://forums.aeva.asn.au/smileys/smiley2.gif A ro...
by Nevilleh
Mon, 28 Jan 2013, 20:28
Forum: Batteries, charging, management and monitoring
Topic: Wanted - an amp hour meter
Replies: 69
Views: 11602

Wanted - an amp hour meter

Well, the A-Hr meter is done. If anyone would like to build one, drop me a PM with your email address and I'll send you the files, PCB Schematic and source code. Here's a component list: PL1     1       2 way header PL2     1       5 way header Pl3     1       3 way header PL4     1     16 Way heade...
by Nevilleh
Sun, 27 Jan 2013, 18:31
Forum: Batteries, charging, management and monitoring
Topic: Wanted - an amp hour meter
Replies: 69
Views: 11602

Wanted - an amp hour meter

Well, you need to power the electronics from somewhere. You have two choices: 12 V or traction battery! If you are going to use a shunt resistor for current measuring, you could solve the isolation problem by powering the electronics from the high voltage. Your problem then is reducing it down to th...
by Nevilleh
Sun, 27 Jan 2013, 18:16
Forum: Batteries, charging, management and monitoring
Topic: Low cost BMS
Replies: 386
Views: 54111

Low cost BMS

I bought all my parts from Element14 and RS Components. I find the shipping charges from Mouser are quite exorbitant. The PicKit 3 programmer is good value direct from Microchip and its easy to use. You plug it and click on a couple of buttons. That lets you experiment with different settings eg bal...
by Nevilleh
Sun, 27 Jan 2013, 14:30
Forum: Batteries, charging, management and monitoring
Topic: Wanted - an amp hour meter
Replies: 69
Views: 11602

Wanted - an amp hour meter

This is a nice AH meter: http://www.lightobject.com/Programmable-Digital-AH-meter-Ideal-for-battery-monitoring-P278.aspx I beg to differ, its not nice at all! Crappy, 7 segment led display and uses a shunt with no isolation. A shunt is NOT the way to go - for the reasons I have mentioned before. As...
by Nevilleh
Sun, 27 Jan 2013, 12:26
Forum: Batteries, charging, management and monitoring
Topic: Wanted - an amp hour meter
Replies: 69
Views: 11602

Wanted - an amp hour meter

I'm not sure I agree, because the -ve of the 12 V system is connected to the frame/chassis - otherwise you'd have to run 2 wires to everything! - and by using a voltage divider you connect the -ve of the high voltage battery to the chassis as well. This means that if you were to inadvertently touch ...
by Nevilleh
Sun, 27 Jan 2013, 01:46
Forum: Batteries, charging, management and monitoring
Topic: Wanted - an amp hour meter
Replies: 69
Views: 11602

Wanted - an amp hour meter

You do realise that a divider attached directly to the battery still doesn't provide isolation, don't you? If you are powering the voltmeter from 12 V, it means the -ve battery terminal is now commoned up with the 12 V system -ve.

A can opener has got to be better than the bicycle!!
by Nevilleh
Sat, 26 Jan 2013, 21:30
Forum: Batteries, charging, management and monitoring
Topic: Wanted - an amp hour meter
Replies: 69
Views: 11602

Wanted - an amp hour meter

I don't really want any connections between the high voltage battery and the 12V circuits. This means using a linear opto-coupler and a small dc-dc converter, all of which adds to the cost. The CA has these connections and doesn't appear to be isolated. Might be OK for systems up to 48 V but not so ...
by Nevilleh
Thu, 24 Jan 2013, 16:37
Forum: Batteries, charging, management and monitoring
Topic: Wanted - an amp hour meter
Replies: 69
Views: 11602

Wanted - an amp hour meter

No HV connection needed, its powered off 12v and hence isolated. Maybe a 3 or 4 digit lcd might do, I used the 16 x 2 because its there, but it might be cheaper to use a lesser thing. Actually, the 3 1/2 digit things are usually 7 segment displays and you have to drive them with something. Also, the...
by Nevilleh
Thu, 24 Jan 2013, 14:12
Forum: Batteries, charging, management and monitoring
Topic: Wanted - an amp hour meter
Replies: 69
Views: 11602

Wanted - an amp hour meter

You're quite right, of course. The sensor should be placed on the battery lead. I was looking at the lcd and wanted to pad it out a bit - just "Amps" looked a bit plain! - and I unthinkingly put the word "Motor" in just because it looked nice. I'll change it to "Batt".
by Nevilleh
Thu, 24 Jan 2013, 12:17
Forum: Admin Notices
Topic: Forum Software Upgrade
Replies: 22
Views: 4045

Forum Software Upgrade

Andrew wrote:

As for the error with uploading images, I've turned off the file scanning as that is no longer relevant with this new version. Please try uploading again.


Thanks, it works OK now.
by Nevilleh
Thu, 24 Jan 2013, 12:14
Forum: Batteries, charging, management and monitoring
Topic: Wanted - an amp hour meter
Replies: 69
Views: 11602

Wanted - an amp hour meter

Andrew says he has turned off the image file scan (which has prevented me from uploading images) so here's a picture of my display, just to test that it now works: http://forums.aeva.asn.au/uploads/683/AH_meter1.jpg The features of this thing are: Uses Tamura Hall-effect current sensor for 0 - 511 A...
by Nevilleh
Wed, 23 Jan 2013, 20:00
Forum: Admin Notices
Topic: Forum Software Upgrade
Replies: 22
Views: 4045

Forum Software Upgrade

I am now quite unable to upload any images, doesn't matter what format, every attempt is greeted with this:

"Error uploading file!!.
The file failed the security scan and has been deleted as it may contain malicous code"
by Nevilleh
Wed, 23 Jan 2013, 18:44
Forum: Batteries, charging, management and monitoring
Topic: Wanted - an amp hour meter
Replies: 69
Views: 11602

Wanted - an amp hour meter

Well, I've made an ammeter/amp-hour meter by modifying an old bms control board. It displays instantaneous amps (sampled 10 times per second) and amp-hours used. It uses a PIC16F1826 micro, a 16 x 2 lcd, a 5V regulator, some R's and C's, an op-amp and a Tamura current sensor. My one works from 0 - 5...
by Nevilleh
Sun, 20 Jan 2013, 12:12
Forum: Batteries, charging, management and monitoring
Topic: Wanted - an amp hour meter
Replies: 69
Views: 11602

Wanted - an amp hour meter

I'm willing to help fund any development of a one-off. BTW Justin of E-bikes.ca has offered to hack the CA so it can read 7 V from a divider, and report full 700 V on the screen. I will definitely use this for both the CRX and the bike, but it need not be located on the dash / instrument panel. I d...
by Nevilleh
Sat, 19 Jan 2013, 20:28
Forum: Batteries, charging, management and monitoring
Topic: Wanted - an amp hour meter
Replies: 69
Views: 11602

Wanted - an amp hour meter

Just came across this thread and, believe it or not, I started work on just such a thing yesterday! I have a spare bms master unit and I thought I'd make an AH meter out of it with a view to including in the next iteration of the master unit, but in the meantime its fairly easy to do as a stand-alon...
by Nevilleh
Sat, 19 Jan 2013, 16:50
Forum: Batteries, charging, management and monitoring
Topic: Low cost BMS
Replies: 386
Views: 54111

Low cost BMS

Thanks for the suggestion, but the .jpg image was 130 Kb and the .gif one is 2 Mb which is too large for this system. Beaten every which way! I'll have to try something else. Printed it, re-scanned it at 100 dpi resolution and saved it as a gif. Let's see what we have : No, same error: Error uploadi...
by Nevilleh
Sat, 19 Jan 2013, 13:05
Forum: Batteries, charging, management and monitoring
Topic: Low cost BMS
Replies: 386
Views: 54111

Low cost BMS

The bms outputs cell voltage data and I have started to collect and analyse it with an interesting result: Cell 9 has a higher internal resistance than the others, giving a greater voltage drop under load. I have not, as yet, checked the terminals or links - could be a slightly high resistance conne...
by Nevilleh
Mon, 14 Jan 2013, 21:21
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 342369

Weber and Coulomb's MX-5

I think you should scrap the MX-5 and shift everything into a bigger car! That way you could spend another four years happily puddling around with the project. Obviously the journey is far more important than the destination. Image
by Nevilleh
Sun, 13 Jan 2013, 15:46
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 342369

Weber and Coulomb's MX-5

I remember pulling the wiring harness out of a Mitsubishi some years ago and i could pick the whole thing up with one hand, so it wouldn't have been 10 kg. I doubt you could save much by removing a few wires. You might do away with power steering, I find it quite unnecessary in the BMW. Also the 12 ...
by Nevilleh
Sat, 12 Jan 2013, 12:11
Forum: Members Machines
Topic: Nevilleh's BMW
Replies: 337
Views: 57559

Nevilleh's BMW

lately I imported an eRider motorcycle (what a piece of crap that turned out to be, yeh, the build quality is pretty bad did you get one with the sevcon controller? if so, they run ok while they work, but getting those panels off is a real PITA. Doing second hand vectrix is more profitable - simila...
by Nevilleh
Fri, 11 Jan 2013, 20:49
Forum: Members Machines
Topic: Nevilleh's BMW
Replies: 337
Views: 57559

Nevilleh's BMW

After several cycles of top balancing, I decided the shunting threshold was set a bit high and after looking at the charge curve for a CALB cell, I dropped it 3.360 V with much better results. I am now finding some 30-odd cells are shunting when the first one reaches the cut-off of 3.60 V. ie 30 cel...
by Nevilleh
Fri, 11 Jan 2013, 12:53
Forum: Members Machines
Topic: Mr C's 2001 Prius revival
Replies: 19
Views: 3674

Mr C's 2001 Prius revival

Do you get battery errors even when the thing is just turned on and not moving? ie the cell imbalances exist even under no load? If so, then there is tech term for that - bu@#%#ed!