Search found 564 matches

by 4Springs
Sun, 21 Jul 2019, 16:24
Forum: Renewable Energy and Storage (Non-EV)
Topic: Low Cost BMS for Home Storage Batteries
Replies: 61
Views: 6018

Re: Low Cost BMS for Home Storage Batteries

Are you intending to use CANbus comms with your SP Pro or set it up standalone with a customized version of the generic LiFePO4 settings? The intention at this stage is to use a 48V SP Pro, and let it think that it is a lead-acid battery. I won't be using CANbus, but will be adjusting settings to i...
by 4Springs
Sun, 21 Jul 2019, 16:10
Forum: Renewable Energy and Storage (Non-EV)
Topic: Low Cost BMS for Home Storage Batteries
Replies: 61
Views: 6018

Re: Low Cost BMS for Home Storage Batteries

Is the oven for reflow? Indeed it is. Was also used for fruit buns at one stage. It has a thermostat, we set it to about 200 degrees Celcius. Watch the circuit boards through the glass window to see when the solder melts - then leave it for 30 seconds more to make sure. The whole process takes abou...
by 4Springs
Sun, 21 Jul 2019, 08:11
Forum: Renewable Energy and Storage (Non-EV)
Topic: Low Cost BMS for Home Storage Batteries
Replies: 61
Views: 6018

Re: Low Cost BMS for Home Storage Batteries

Software - what are we going to do with these things?? The current software is available here: https://sourceforge.net/projects/low-cost-bms/files/Programming/ The current Cell Module software is version 1.10. I don't expect that this will change. The latest Master software is H1.00. I've forked to ...
by 4Springs
Sun, 21 Jul 2019, 06:33
Forum: Renewable Energy and Storage (Non-EV)
Topic: Low Cost BMS for Home Storage Batteries
Replies: 61
Views: 6018

Re: Low Cost BMS for Home Storage Batteries

Well, after a few working bees over the last several weekends, all the boards in the group buy are now accounted for. Some were sent to folks (mostly interstate) for them to assemble themselves. We had to remove a resistor from each cell module board (placed there by mistake when I specified the wro...
by 4Springs
Mon, 10 Jun 2019, 19:35
Forum: Hyundai
Topic: Hyundai Sales Tactics
Replies: 38
Views: 1716

Re: Hyundai Sales Tactics

Theres not really any aim or direction to this conversation beyond conversation. I like that - very quotable. My 2c worth about Hyundai sales people. We have been working with the single Blue Drive Hyundai dealer in our state. They don't know a heap about their cars, but can you blame them? They re...
by 4Springs
Mon, 10 Jun 2019, 05:36
Forum: Hyundai
Topic: Hyundai Sales Tactics
Replies: 38
Views: 1716

Re: Hyundai Sales Tactics

If you want a froot or frunk or whatever that thing is in the front get a Tesla. It's definitely a froot. Glad to hear someone else using the term! There is so much space under the bonnet of a Kona, I wonder how long it will be before you can buy a bolt-in insert. Remove the dinky plastic cover thi...
by 4Springs
Wed, 05 Jun 2019, 16:30
Forum: Charging Infrastructure
Topic: Dual Charging
Replies: 5
Views: 426

Re: Dual Charging

Is that a cost limitation or a practical limitation? The DC fast charging requires interfacing with the fast charger computer. So it's a combination of having the right voltage as jonescg says, and working out the software. You'd need to have a good idea what your battery is doing so you can give t...
by 4Springs
Wed, 05 Jun 2019, 16:15
Forum: General EV Discussion
Topic: Bring on the BERM please
Replies: 30
Views: 3126

Re: Bring on the BERM please

I see, thanks. The tight turning circle may negate the need for the reverse mowing I do now. I reverse mow in part because my mower does not have a good turning circle, and partly because it can go instantaneously from forwards to reverse, so it's very easy to do. I may be able to do it in circles i...
by 4Springs
Mon, 03 Jun 2019, 19:15
Forum: Renewable Energy and Storage (Non-EV)
Topic: BMS for AVASS cells, 16S LiFePO4
Replies: 10
Views: 652

Re: BMS for AVASS cells, 16S LiFePO4

the ZEVA system is looking quite attractive. I came here to suggest the Zeva unit, but I see that you've found it! Services 12 cells per board, so you'd need two if you have 16 cells. This is a spaghetti BMS (wires go from one board to many cells), as opposed to a daisy-chain BMS (wires go from the...
by 4Springs
Mon, 03 Jun 2019, 18:47
Forum: Charging Infrastructure
Topic: Dual Charging
Replies: 5
Views: 426

Re: Dual Charging

I haven't seen a DIY vehicle with DC fast charging.
No reason why you couldn't use two AC charging sockets at once. Need a few onboard chargers, but if money is no object...
by 4Springs
Sat, 01 Jun 2019, 18:54
Forum: General EV Discussion
Topic: Bring on the BERM please
Replies: 30
Views: 3126

Re: Bring on the BERM please

I'd love a catcher, but that one looks quite convoluted and likely to clog up. Also difficult to empty - you have to get off the mower! I'd been assuming that I'd get one of these mowers (sans catcher) before spring. But the reversing problem looks like it might change my mind. How exactly does it w...
by 4Springs
Sat, 25 May 2019, 06:21
Forum: Renewable Energy and Storage (Non-EV)
Topic: Low Cost BMS for Home Storage Batteries
Replies: 61
Views: 6018

Re: Low Cost BMS for Home Storage Batteries

Have you got any spares in those 400 boards? Yes. Final totals were 352 cell module and 37 master boards ordered by people in the group buy. There are set order quantities at the board manufacturing place, so I ordered 400 module and 40 master boards. I've updated the Airtable form: https://airtabl...
by 4Springs
Sun, 19 May 2019, 07:56
Forum: Batteries, charging, management and monitoring
Topic: Low cost BMS
Replies: 386
Views: 53189

Re: Low cost BMS

I've been working on this project again, making a version for home storage batteries. (see the other topic here: http://forums.aeva.asn.au/viewtopic.php?f=64&t=5577 ) In working on a new version, I've replaced the diode on the module board with a MOSFET. This means that the shunt current can be prop...
by 4Springs
Sun, 12 May 2019, 16:40
Forum: Renewable Energy and Storage (Non-EV)
Topic: Low Cost BMS for Home Storage Batteries
Replies: 61
Views: 6018

Re: Low Cost BMS for Home Storage Batteries

Ok, I've placed the order for the modules. I ended up not putting in an explicit pull-down resistor, although as Peter said, one could be added using the through-hole pads. I eventually figured out how to properly search the components available through Seeed. The secret is to click on the link to '...
by 4Springs
Sun, 12 May 2019, 06:14
Forum: Renewable Energy and Storage (Non-EV)
Topic: Low Cost BMS for Home Storage Batteries
Replies: 61
Views: 6018

Re: Low Cost BMS for Home Storage Batteries

Some questions for the learned folk here: 1. I've put holes under the shunt resistors in an attempt to help them dissipate heat. The idea is that air will hopefully circulate, but I have no idea if that will be the case. Any comments on this? 2. I have no pull-down resistor on the MOSFET gates. My r...
by 4Springs
Sun, 12 May 2019, 05:40
Forum: Renewable Energy and Storage (Non-EV)
Topic: Low Cost BMS for Home Storage Batteries
Replies: 61
Views: 6018

Re: Low Cost BMS for Home Storage Batteries

So here are the current circuit diagrams and PCB layouts for the master: BMSMaster Storage - Schematic.pdf BMSMaster Storage-Top1.jpg BMSMaster Storage-bottom1.jpg Main differences between this one and the last version posted is that extra MOSFETs have been added so that we have the option of up to ...
by 4Springs
Sun, 12 May 2019, 05:08
Forum: Renewable Energy and Storage (Non-EV)
Topic: Low Cost BMS for Home Storage Batteries
Replies: 61
Views: 6018

Re: Low Cost BMS for Home Storage Batteries

Peter has raised a request and a concern on the cell-top moudule (in an email). The request is that holes be added to allow for through-hole or externally mounted shunt resisttor(s) and driver if desired. The concern is that the diode (DNBT8105) might not be passing the current that I think it is. W...
by 4Springs
Fri, 10 May 2019, 16:45
Forum: Renewable Energy and Storage (Non-EV)
Topic: Low Cost BMS for Home Storage Batteries
Replies: 61
Views: 6018

Re: Low Cost BMS for Home Storage Batteries

Had a request to modify the module board. Here is the latest Top layer: CellTopBMS-Top.jpg Bottom layer: CellTopBMS_Bottom.jpg I've added holes so that you can choose to add one or two through-hole balancing resistors. Also a hole so you can tap into the -ve with a wire if you like. Looking at these...
by 4Springs
Sun, 05 May 2019, 19:08
Forum: Renewable Energy and Storage (Non-EV)
Topic: Low Cost BMS for Home Storage Batteries
Replies: 61
Views: 6018

Re: Low Cost BMS for Home Storage Batteries

I've just got some cells from the latest AEVA battery sale - is it too late to order? No, not quite. I've been busy with a show for the last few days so I haven't ordered the parts yet. Will it keep a 48V 460A pack balanced? I'm betting on it, but I can't guarantee it. A version with a lower shunt ...
by 4Springs
Sat, 27 Apr 2019, 06:39
Forum: Renewable Energy and Storage (Non-EV)
Topic: Low Cost BMS for Home Storage Batteries
Replies: 61
Views: 6018

Re: Low Cost BMS for Home Storage Batteries

Would it work on NCMs? The BMS? Sure. It would suit many types of cell, the only difference between chemistries (from a BMS point of view) is the cell voltage range. According to a quick Google search, NCM has a higher voltage than LFP, apparently up to 4.2V. This BMS uses a PIC12F1822 microcontrol...
by 4Springs
Sat, 27 Apr 2019, 06:25
Forum: Renewable Energy and Storage (Non-EV)
Topic: Low Cost BMS for Home Storage Batteries
Replies: 61
Views: 6018

Re: Low Cost BMS for Home Storage Batteries

Is it possible to balance as the cells are charging? Yes, but fiddly and there isn't any need. As Coulomb said, you can't figure out which cell needs balancing while charging, only when the charge is almost complete. But you could remember which one needed balancing last time, and use that info to ...
by 4Springs
Thu, 25 Apr 2019, 07:43
Forum: Renewable Energy and Storage (Non-EV)
Topic: Low Cost BMS for Home Storage Batteries
Replies: 61
Views: 6018

Re: Low Cost BMS for Home Storage Batteries

Ok, so now I need to develop a program for the Master to suit home storage. This is a bit different to a car BMS, as it needs to be able to be set-and-forget. A car BMS is able to rely on the driver for some functions. Here is my logic table: Screenshot at 2019-04-25 09-18-55.png Charging: • Charger...
by 4Springs
Tue, 23 Apr 2019, 16:06
Forum: Renewable Energy and Storage (Non-EV)
Topic: Low Cost BMS for Home Storage Batteries
Replies: 61
Views: 6018

Re: Low Cost BMS for Home Storage Batteries

Something else that you'll need if you are going to build and program these yourself is a programming tool. I used the PICkit 3, which is available from Microchip (who make it), or I see that Element 14 also sell it for $69. The PICkit 4 is now available, but it looks like it doesn't have the very u...
by 4Springs
Tue, 23 Apr 2019, 15:33
Forum: Renewable Energy and Storage (Non-EV)
Topic: Low Cost BMS for Home Storage Batteries
Replies: 61
Views: 6018

Re: Low Cost BMS for Home Storage Batteries

Ok, for those buying their own components, here are some screenshots of my spreadsheet:
Screenshot at 2019-04-23 17-26-37.png
Screenshot at 2019-04-23 17-26-37.png (101.17 KiB) Viewed 870 times
Screenshot at 2019-04-23 17-30-16.png
Screenshot at 2019-04-23 17-30-16.png (55.82 KiB) Viewed 870 times
Send me a message if you'd like the original sheet.
by 4Springs
Mon, 22 Apr 2019, 07:10
Forum: Renewable Energy and Storage (Non-EV)
Topic: Low Cost BMS for Home Storage Batteries
Replies: 61
Views: 6018

Re: Low Cost BMS for Home Storage Batteries

The outcome from all this testing is that I'm now ready to place orders for the boards. So far I've received orders for an even 300 of the module boards, spread out over 13 customers. You can order complete boards (i.e. with components), or boards only, or a combination. Still time to order if you'd...