Search found 219 matches

by Renard
Sun, 10 Mar 2013, 23:28
Forum: Batteries, charging, management and monitoring
Topic: Low cost BMS
Replies: 386
Views: 54120

Low cost BMS

I presume the lump you refer to is the vent plug. It doesn't impinge on the board. I suppose that more balancing resistors would be good, but with more resistors you may have to consider upgrading the transistor which switches them. I note that Neville's existing board produces about 2W when top bal...
by Renard
Sat, 09 Feb 2013, 14:27
Forum: Technical and conversion discussion
Topic: Do yourself a favour...
Replies: 12
Views: 1969

Do yourself a favour...

50mA for 30ms kills you, or is it 30mA for 50ms?
by Renard
Thu, 07 Feb 2013, 23:29
Forum: Members Machines
Topic: Renard's BMW
Replies: 237
Views: 28803

Renard's BMW

Unless both sides of the charger are disconnected when not charging, I don't think that's true. I don't know if you switch the negative output of the charger, or if the charger does it internally (I suspect the charger disconnects only the positive output). My charger(s) will be sitting on a garage...
by Renard
Thu, 07 Feb 2013, 15:27
Forum: Members Machines
Topic: Renard's BMW
Replies: 237
Views: 28803

Renard's BMW

Oh. But isn't the control circuitry connected with the negative end of the charger output? In other words, aren't you thereby connecting pack negative to chassis? A quick check would be to use a multimeter to check for continuity between the green control lead and charger minus. I think that the re...
by Renard
Thu, 07 Feb 2013, 00:24
Forum: Members Machines
Topic: Renard's BMW
Replies: 237
Views: 28803

Renard's BMW

I guess 5 A is pretty gentle for those 100 Ah (?) cells, but one commandment we learned is this: "Thou shalt clamp whenever thou chargeth". No permanent damage seems to come from swelling, but it's just so creepy and it doesn't feel good for the expensive cells. Impressive pack, BTW. Yes, it's quit...
by Renard
Thu, 07 Feb 2013, 00:19
Forum: Members Machines
Topic: Renard's BMW
Replies: 237
Views: 28803

Renard's BMW

How did you generate the 2-5 V signal? External supply or did you use the +12 V-Gnd-Enable arrangements as per the manual? Edit - OK your BMS supplies the signal. But I assume you put this between Enable and Gnd on the 7 pin plug? For temporary purposes I used a bench power supply and checked its v...
by Renard
Wed, 06 Feb 2013, 17:50
Forum: Members Machines
Topic: Renard's BMW
Replies: 237
Views: 28803

Renard's BMW

I'm just surfacing after the last ten days. We have been somewhat knocked about by the furious three day cyclonic storm, the power outage for four days, and the trees down on the lines and elsewhere. Then to cap it all, when I was installing comms wiring on the cell-top modules, I accidentally touch...
by Renard
Tue, 05 Feb 2013, 02:46
Forum: Members Machines
Topic: Johny's Electric Vogue
Replies: 287
Views: 41068

Johny's Electric Vogue

Sincere congratulations on your engineer's approval. You must feel like a proud new parent, and as relieved as a new mother.
by Renard
Sun, 27 Jan 2013, 18:05
Forum: Batteries, charging, management and monitoring
Topic: Low cost BMS
Replies: 386
Views: 54120

Low cost BMS

My experience with the cell-top modules: The micros came pre-programmed from Microchip Direct. But they charge US$29 for a set-up fee and US$60 minimum charge for programming. Decide for yourself if it's better to buy the PIC programmer for some $50 or so. The resistors came mostly from Rockby who o...
by Renard
Sun, 27 Jan 2013, 18:00
Forum: Members Machines
Topic: Renard's BMW
Replies: 237
Views: 28803

Renard's BMW

OK 4 springs, comments on the low cost BMS thread.
by Renard
Sun, 27 Jan 2013, 17:58
Forum: Batteries, charging, management and monitoring
Topic: Wanted - an amp hour meter
Replies: 69
Views: 11602

Wanted - an amp hour meter

   Sure the ammeter 75 mV sense wires and divider negative are connected to the HV negative, but the HV positive is separated from the rest by a large resistor. Remember that ordinary resistors are not rated for high voltage. And one would have two or preferably more high value resistors each conne...
by Renard
Sun, 27 Jan 2013, 14:23
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 Renard
Sun, 27 Jan 2013, 01:41
Forum: Members Machines
Topic: Renard's BMW
Replies: 237
Views: 28803

Renard's BMW

I could have put 18 to 20 boards on one tray, but in fact I did them about six at a time to vary the monotony of pasting and placing.
by Renard
Sat, 26 Jan 2013, 23:40
Forum: Members Machines
Topic: Renard's BMW
Replies: 237
Views: 28803

Renard's BMW

Ten days on and I've just finished 120 modules. I had to take a day off half way through as I was going a bit crazy. Now, I just feel wacked. I had ordered 120 boards and 120 micros, and of the 120, I managed to screw up only two, so that leaves me six spares over and above the 112 that I need. The ...
by Renard
Wed, 16 Jan 2013, 21:26
Forum: Members Machines
Topic: Renard's BMW
Replies: 237
Views: 28803

Renard's BMW

Oh I'm so excited. I can hardly believe it! The BMS worked first time. Oh my god, I didn't expect that. http://forums.aeva.asn.au/uploads/1659/P1010161.jpg http://forums.aeva.asn.au/uploads/1659/P1010162.jpg http://forums.aeva.asn.au/uploads/1659/P1010163.jpg The only hitch was wondering whether the...
by Renard
Tue, 15 Jan 2013, 17:54
Forum: Members Machines
Topic: Renard's BMW
Replies: 237
Views: 28803

Renard's BMW

   Renard, I'd double check the recommended hookup for your breaker in order to realize the full 500vdc rating. It may not actually be a 2-pole breaker as you seem to have it hooked up. As for the ABS, many cars will have the ABS light on until the car starts moving above a certain speed and the co...
by Renard
Tue, 15 Jan 2013, 03:00
Forum: Members Machines
Topic: Renard's BMW
Replies: 237
Views: 28803

Renard's BMW

Slow work this last week or so, as the shed gets very hot in this weather. I've been working out how to wire up all the ELV functions, and it's a messy business. For one thing, the BMW fuse box is just STUFFED with wiring. I had to get into it to pass a few wires through it and to get a lead for the...
by Renard
Sun, 13 Jan 2013, 13:55
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 342416

Weber and Coulomb's MX-5

Are the chargers hard-wired in? If they were detachable, you could claim that you were only going to charge at home, and then the charger weight could be subtracted.

Edit: I now remember you have just the one charger, but it weighs a lot. (Can't find the data offhand.)
by Renard
Sat, 12 Jan 2013, 20:09
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 342416

Weber and Coulomb's MX-5

Two of my -- fortunately much smaller -- under-the-rear-seat boxes also have to go in from underneath the car. So I'm curious to know -- what I can't work out from the photos -- whether you raised the box or lowered the car or both?
by Renard
Sat, 05 Jan 2013, 14:48
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 342416

Weber and Coulomb's MX-5

Congratulations! That must be very satisfying to get those boxes in and bedded down. Fingers crossed that they don't have to come out again. I can see that your construction methods require you to put the boxes in assembled rather than to populate them in situ. The orange conduit which I used respon...
by Renard
Fri, 28 Dec 2012, 21:14
Forum: Members Machines
Topic: Renard's BMW
Replies: 237
Views: 28803

Renard's BMW

Today I installed the DC/DC converter. I have used the place previously occupied by the engine control module; it is well protected from water and dirt, and its only disadvantage is that it will be troublesome to get at it if the unit should fail. (If that happens, I'll re-locate it to the boot. Wit...
by Renard
Fri, 28 Dec 2012, 14:23
Forum: Members Machines
Topic: Nevilleh's BMW
Replies: 337
Views: 57561

Nevilleh's BMW

If you are looking for thin aluminium shim on a Sunday when nothing is open, go to the local shop and buy a can of Coke. Its about .2 mm thick and perfect for the job! You can even drink the Coke, although not recommended. This remark brings to mind a passage in 'Zen and the art of motorcycle maint...
by Renard
Wed, 26 Dec 2012, 22:47
Forum: Members Machines
Topic: Renard's BMW
Replies: 237
Views: 28803

Renard's BMW

Nevilleh wrote:
Get an oven!

Fortunately, I have an oven of just the right size sitting in the shed.
(Oh wonderful cornucopian shed that has such things within it!)
by Renard
Wed, 26 Dec 2012, 20:55
Forum: Members Machines
Topic: Renard's BMW
Replies: 237
Views: 28803

Renard's BMW

The last month has been spent organising wiring and figuring out where to put the ELV control circuits. I have just completed a little circuit designed to interface the BMS (Neville's "Low-cost BMS") to the TC chargers. Neville's Master unit has two FET switches, one closing when one cell shunt turn...
by Renard
Sun, 16 Dec 2012, 13:39
Forum: Members Machines
Topic: Weber and Coulomb's MX-5
Replies: 1698
Views: 342416

Weber and Coulomb's MX-5

Looking at your photos, I'm reminded of those diabolical wooden puzzle blocks which are so tricky to take apart and re-assemble. I've been trying hard, and mostly failing, while doing my conversion, to achieve independent access to components. That is, not to have to take the whole thing apart to ge...