tag:blogger.com,1999:blog-3086978695636448584.post4049292847870514571..comments2024-02-26T18:53:40.799-05:00Comments on Adventures of Tanglewood: Building a Battery Management System (BMS)Peter Haydenhttp://www.blogger.com/profile/06586816406202219798noreply@blogger.comBlogger26125tag:blogger.com,1999:blog-3086978695636448584.post-31611071409789967672021-11-01T06:42:48.738-04:002021-11-01T06:42:48.738-04:00Hi Mike,
Sorry for the delay on your comment. I ...Hi Mike,<br /><br />Sorry for the delay on your comment. I have moderation enabled and I have to approve comments before they get posted. You can thank the spammers for that.<br /><br />Anyway, the answer is yes and no. I got the Canbus interface working and have the IDEC PLC sending AC power info on NMEA 2000, but I had to do a pretty big hack to get it to work. And 90% of the N2K messages Peter Haydenhttps://www.blogger.com/profile/06586816406202219798noreply@blogger.comtag:blogger.com,1999:blog-3086978695636448584.post-33757504911143959962021-10-31T22:07:59.374-04:002021-10-31T22:07:59.374-04:00Hey Peter, we’re you able to get the IDEC PLC to r...Hey Peter, we’re you able to get the IDEC PLC to receive info from the NMEA 2000 network? I have been thinking about a raspberry pi or IDEC PLC to gather my engine info and display it digitally. Mikehttps://www.blogger.com/profile/02411959471437603645noreply@blogger.comtag:blogger.com,1999:blog-3086978695636448584.post-80524659072459933002020-07-13T19:40:38.239-04:002020-07-13T19:40:38.239-04:00Hi Andy,
Good questions. I'll do a quick blo...Hi Andy,<br /><br />Good questions. I'll do a quick blog post to answer since they are of general interest.Peter Haydenhttps://www.blogger.com/profile/06586816406202219798noreply@blogger.comtag:blogger.com,1999:blog-3086978695636448584.post-53364643789929395572020-07-13T04:16:51.168-04:002020-07-13T04:16:51.168-04:00Very interesting and a well thought through approa...Very interesting and a well thought through approach!<br /><br />Two questions:<br /><br />1) do you plan to have some sort of balancing done to the battery also? Some balancing resistors controlled by the PLC perhaps?<br /><br />2) do you plan to count the state of charge amps in/out with the PLC or is this done externally?andyhttp://www.google.comnoreply@blogger.comtag:blogger.com,1999:blog-3086978695636448584.post-89948637435015249942019-06-23T16:16:04.894-04:002019-06-23T16:16:04.894-04:00Hi Josh,
Sorry for the delay. I've been gett...Hi Josh,<br /><br />Sorry for the delay. I've been getting spammed on comments, so had to put them under moderation and approval, hence the delay in yours getting posted.<br /><br />I got the fuse holders (and a bunch of other stuff) from Newark Electronics (newark.com) They have quite a range of product. The particular fuse holder is part number 12J4031.<br /><br />My fusing system works,Peter Haydenhttps://www.blogger.com/profile/06586816406202219798noreply@blogger.comtag:blogger.com,1999:blog-3086978695636448584.post-61098965128985713882019-06-22T18:55:56.287-04:002019-06-22T18:55:56.287-04:00Where did you get your fuse holders? I I have been...Where did you get your fuse holders? I I have been trying to find some that can be crimped inline with 22awg wire. Joshhttp://www.southernauroratn.comnoreply@blogger.comtag:blogger.com,1999:blog-3086978695636448584.post-52007373649505857412018-12-03T14:09:55.786-05:002018-12-03T14:09:55.786-05:00Glad you found it. Did you see the new blog entry...Glad you found it. Did you see the new blog entry with the results of the experiment you suggested? I'm guessing it's all about the degree of inter-channel isolation in the particular sensor. I think you said you were using a Pi sensor of some sort? Would you have an exact model?Peter Haydenhttps://www.blogger.com/profile/06586816406202219798noreply@blogger.comtag:blogger.com,1999:blog-3086978695636448584.post-41079848526988844252018-12-03T02:30:07.589-05:002018-12-03T02:30:07.589-05:00Thanks! I found the notify box.Thanks! I found the notify box.Bob Ebaughhttps://www.blogger.com/profile/12125352505413185761noreply@blogger.comtag:blogger.com,1999:blog-3086978695636448584.post-627526887546568902018-11-29T22:16:05.706-05:002018-11-29T22:16:05.706-05:00I'll be back in front of the BMS in the next d...I'll be back in front of the BMS in the next day or two and will definitely give it a try. That's also very interesting to see the difference in input impedance between the spec you referenced and the 4117 manual that I have. Makes you wonder.....<br /><br />When you post a comment on Blogger, there is a check box off to the right for "Notify me". If you check that, you Peter Haydenhttps://www.blogger.com/profile/06586816406202219798noreply@blogger.comtag:blogger.com,1999:blog-3086978695636448584.post-49737500480324016512018-11-29T20:40:27.296-05:002018-11-29T20:40:27.296-05:00There isn't any impedance between the ADC chan...There isn't any impedance between the ADC channels...unless you make it. The spec I quoted was from this link:<br /><br />https://advdownload.blob.core.windows.net/productfile/PIS/ADAM-4117/Product%20-%20Datasheet/ADAM-411720180910101949.pdf<br /><br />Pull one of your fuses and let me know what you see....<br /><br />Is there a way on Blogger to get an email if this thread is updated? I Bob Ebaughhttps://www.blogger.com/profile/12125352505413185761noreply@blogger.comtag:blogger.com,1999:blog-3086978695636448584.post-90829757017631856332018-11-26T18:59:21.507-05:002018-11-26T18:59:21.507-05:00I think it will depend on the impedance between th...I think it will depend on the impedance between the adjacent channels, right?<br /><br />I'm also seeing 20M ohms input impedance in the specs for the ADAM 4117. Where are you seeing 800K? And I don't see any spec for inter-channel impedance.Peter Haydenhttps://www.blogger.com/profile/06586816406202219798noreply@blogger.comtag:blogger.com,1999:blog-3086978695636448584.post-6209667849016346632018-11-26T18:01:24.937-05:002018-11-26T18:01:24.937-05:00You will need a slight imbalance in the readings t...You will need a slight imbalance in the readings to see. My ADC is specified as >200K ohms input resistance the ADAM datasheet menioned a more specific 800K ohms. Maybe this will help:<br /><br />In4- I----------------------------C4-<br /> 800K Ohms<br />In4+ I----------------I<br /> IIII-----------C4+ and C5-<br />In5- I----------------I<br /> 800K Bob Ebaughhttps://www.blogger.com/profile/12125352505413185761noreply@blogger.comtag:blogger.com,1999:blog-3086978695636448584.post-16448402705314916562018-11-25T19:40:29.503-05:002018-11-25T19:40:29.503-05:00Awesome links, Frode, thanks! That conforms what ...Awesome links, Frode, thanks! That conforms what I have heard anecdotally.Peter Haydenhttps://www.blogger.com/profile/06586816406202219798noreply@blogger.comtag:blogger.com,1999:blog-3086978695636448584.post-28798520594290951842018-11-25T19:27:23.532-05:002018-11-25T19:27:23.532-05:00Back in 2012, EVtv posted a chart showing their re...Back in 2012, EVtv posted a chart showing their recorded temperature increases in CALB cells under various charge rates. Essentially, it shows very little increase at charge rates of 0.5C and below.<br /><br /><b>Chart:</b> http://23.21.184.60/evtv-word-press/wp-content/uploads/2012/06/1CAtemperature.jpg<br /><br /><b>Post:</b> http://evtv.me/2012/06/battery-jump-shift/Frodehttps://www.blogger.com/profile/05703518356151131100noreply@blogger.comtag:blogger.com,1999:blog-3086978695636448584.post-89401381408230297002018-11-22T01:50:53.515-05:002018-11-22T01:50:53.515-05:00Let us know if you do that contactor experiment an...Let us know if you do that contactor experiment and what you find! <br /><br />Note that you said experiment might also put some wear and tear on your overcurrent protection, although if that occurs it will probably be in the direction of failing safe.<br /><br />I have heard that a good rule of thumb is to assume 30 times the steady-state current for inrush, in the absence of the ability to Unknownhttps://www.blogger.com/profile/06969235034093765610noreply@blogger.comtag:blogger.com,1999:blog-3086978695636448584.post-82384182609973444862018-11-21T19:08:54.008-05:002018-11-21T19:08:54.008-05:00Thanks for the comments. They are very helpful. ...Thanks for the comments. They are very helpful. There are two sense wires (plus and minus) for each cell - actually each set of paralleled cells. So the Plus sense for C3 is electrically the same as the minus sense for C4. But they are still different sense wires for each. Regardless, I'll double check your test. As I was hooking it up, each voltage started to read when I hooked up the Peter Haydenhttps://www.blogger.com/profile/06586816406202219798noreply@blogger.comtag:blogger.com,1999:blog-3086978695636448584.post-89654001601227722852018-11-21T15:03:11.426-05:002018-11-21T15:03:11.426-05:00Also enjoyed the write up. I built something sim...Also enjoyed the write up. I built something similar using different components. The PLC was a Triangle Research Nano-10, the ADC basically the same as yours, a generic 8 Input from Wayjun and the human interface on HMI Pad by SweetWilliam.<br /><br />The Nano-10 has an Ethernet connection and software allowing a user customizable web page for monitoring and control. If you were an HTML Bob Ebaughhttps://www.blogger.com/profile/12125352505413185761noreply@blogger.comtag:blogger.com,1999:blog-3086978695636448584.post-46685144046935685812018-11-20T02:58:02.531-05:002018-11-20T02:58:02.531-05:00(Sorry, I don't know why it thinks I am "...(Sorry, I don't know why it thinks I am "Unknown.")<br /><br />Re: automation with your PLC, sounds like you have a nice option space there. I agree, do it manually first and see what you think. Keep in mind that you have to turn off the inverter/charger as well in there, if it will otherwise try to bring itself online. Another note: at least with Victron I/Cs, you can also Unknownhttps://www.blogger.com/profile/06969235034093765610noreply@blogger.comtag:blogger.com,1999:blog-3086978695636448584.post-78852266266007952252018-11-19T21:21:35.252-05:002018-11-19T21:21:35.252-05:00Victron has a pre-charge feature built in, and I t...Victron has a pre-charge feature built in, and I think Lithionics as well. I'll have to give some thought to how automated a pre-charge I want. It would actually be pretty easy to have the PLC close a relay to cut in a pre-charge resistor, then after some time delay close the main contactor and release the pre-charge relay. I could also measure the load-side voltage and pre-charge up to Peter Haydenhttps://www.blogger.com/profile/06586816406202219798noreply@blogger.comtag:blogger.com,1999:blog-3086978695636448584.post-59863539421683191232018-11-19T20:26:26.804-05:002018-11-19T20:26:26.804-05:00Re: temp sensors, are you using these only for an ...Re: temp sensors, are you using these only for an emergency disconnect, like if the battery gets hot? Or do you want to detect cold weather and also reduce or shut down charging, etc.?<br /><br />In my case, I only care about thermal runaway, so I am using a string of cheap thermal fuses in series. I just tape them around the batteries in various spots, enough that they will open the main Unknownhttps://www.blogger.com/profile/06969235034093765610noreply@blogger.comtag:blogger.com,1999:blog-3086978695636448584.post-53593645209190643722018-11-19T20:22:04.909-05:002018-11-19T20:22:04.909-05:00Re: pre-charge, I am only aware that there are som...Re: pre-charge, I am only aware that there are some the EV guys use, since they are plugging their car in all the time. <br /><br />What I did is make a very manual pre-charge circuit: a power resistor with an intermittent pushbutton switch that puts it in circuit. When it's time to reconnect the battery, I hold down the "charge" switch for 30 seconds, and on my system that'sUnknownhttps://www.blogger.com/profile/06969235034093765610noreply@blogger.comtag:blogger.com,1999:blog-3086978695636448584.post-44789755568205274222018-11-19T16:06:39.062-05:002018-11-19T16:06:39.062-05:00I just checked out the Gigavac contactors. They a...I just checked out the Gigavac contactors. They are pretty much the same as the TU contactor I'm using now, but significantly lower power consumption. 2W vs 18W to hold it closed. Looks good. Now I just need to figure out this pre-charge thing.....Peter Haydenhttps://www.blogger.com/profile/06586816406202219798noreply@blogger.comtag:blogger.com,1999:blog-3086978695636448584.post-75024807842972599312018-11-19T15:23:22.775-05:002018-11-19T15:23:22.775-05:00Thanks Ben. I appreciate the leads on lower power...Thanks Ben. I appreciate the leads on lower power contactors. And the more I think about it, I'm not comfortable with a latching contactor either, so that's off the table now.<br /><br />You are correct that I don't have any pre-charge circuit, and I have noticed them in other designs. I know they are to reduce arcing, but didn't realize contactors have such different ratings Peter Haydenhttps://www.blogger.com/profile/06586816406202219798noreply@blogger.comtag:blogger.com,1999:blog-3086978695636448584.post-56307830042418003182018-11-19T14:19:52.620-05:002018-11-19T14:19:52.620-05:00Nice write-up, thanks for posting it.
Regarding...Nice write-up, thanks for posting it. <br /><br />Regarding contactors, you might consider a dual-coil design. They use a big coil to move the switch, and then they use a little coil to hold it in place. You should be able to get <2W consumption at 400A or so. If you need more than that, you could parallel two smaller ones. I've been happy with Gigavac's line, and they make them Bennoreply@blogger.comtag:blogger.com,1999:blog-3086978695636448584.post-80321746383853932282018-11-19T07:54:14.326-05:002018-11-19T07:54:14.326-05:00Thanks for the comment, Frode.
I've decided n...Thanks for the comment, Frode.<br /><br />I've decided not to have separate charge and discharge disconnects, and am instead directly controlling the chargers and inverters. On this first system for a land-based home, there are three charger sources (two solar chargers and the inverter/charger), and they can be controlled via a control signal from the BMS. And the only load of any Peter Haydenhttps://www.blogger.com/profile/06586816406202219798noreply@blogger.com