Elcat Lithium Conversion EP6: More TinCanBMS Integration

[@twocvbloke]

Seeing all the wiring in the back makes me think there's a need for some of that corrugated cable trunking stuff (the stuff that has a split through its' length to feed the wires in via), give it lal a nice neater appearance, and hide any bodgery that may be going on too... :D

[@FFcossag]

Hehe, it's gonna get properly tied up once it's more complete. I've just cut open all the looms for reverse engineering and splicing into since there's no documentation or schematics for it.

[@tigerelectronics5966]

I am absolutely loving this project! Also, long time no see!! You need to make a general update video about how your things are doing, I miss your battery and solar videos a lot too! I need to make some update videos myself too... I may or may not have bought sonnenschein batteries myself now... :P Woops!! Heheh! //your biggest fan from sweden 😄

[@FFcossag]

Thanks. Sadly, my things have been fairly stagnant lately. The Elcat project has been basically standing still while we've been working on the BMS, and the rest of my stuff has mostly just been slowly degrading. Those giant Sonnenschein cells turned out not to be so great after all ... I hope you're luckier with yours than I was with mine!

[@tigerelectronics5966]

@@FFcossag I didn't see this reply until after I had watched the diesel video! Such a lovely machine! I am in the same situation right now, I have been too busy working and such so my stuff is all degrading aswell, I have not had any energy to work on my little van either, and unfortunately my electronics projects and solar projects have not been worked on in a while now... Plus there was a fire in our workshop recently, so I dont have anywhere to really do much other than my little outdoor shed x3 So I feel that a lot, I hope things get better. Exciting to hear about the BMS though!! Getting any good progress on it? I am really excited about your elcat van, if I do end up coming over this summer, I would love to see it IRL! :D And aww,, I am so sorry to hear that those big cells didn't last :( Was it the positive plate growth that killed them? Or what went wrong? I remember you made a video about them where you talked a lot about that, and that does seem to be a big problem with sonnenschein batts. I hope mine doesn't develop it too quickly, I bought a more advanced charge coontroller (victron energy something) that is fully adjustable via a app, so I can set my charge voltages and temperature compensation correctly so I don't damage it> I am really excited to get my A600 but I am worried about how it is going with my order because nothing has happened, no updates or anything, I know sonnenschein makes the batteries on demand more or less, but I have not heard anything whatsoever. Also may be able to get my hands on some of those yellow and orange powersafe batteries from work next time they go over them! I dont like those nearly as much as I like sonnenschein but if I can get them for a little more than scrap price, then hell yeah I'll roll with them. they have a VERY tight replacement schedule where I work, they change them every 3 years even if they are just fine!

[@FFcossag]

The BMS is now operational at a very basic level. It might get more development, it might not. I'm not sure what's causing my big cells to fail. The failure mode is excessive self discharge in cells with significant plate growth, so I suspect that they're suffering mechanical failure of the plates. I believe these were run very warm in their original application, which is why they were replaced so young. Still, they've lived through 10 years of warm stand-by use and 4 years of cyclic use by now. You really can't complain at all, they are simply being pushed way past their useful life. Curiously, my older 6 V/300 Ah A600s are aging much better than the 2 V ones, and I often find them taking abut 80 % of the load of the entire system. I also recently got an e-mail from Exide, where they're excusing themselves for having problems migrating to some new system. I bet your order is just a victim of their internal chaos. And yes, grab all 3-year-old Powersafes that you can! They're not super reliable, but you can easily get a year or two of cyclic use out of them at such a young age.

[@tigerelectronics5966]

@@FFcossag Sometimes I Hate KZbin comments, I don't know what I did, but I was typing out my reply and suddenly, everything got deleted! So now I Am typing this up in wordpad, and will copy and paste into KZbin afterwards :P That's very exciting that you got the BMS going!! Also I know how that is like, hehe. I have many projects that are just like that :P They work just good enough, and then it stays that way for years (or forever) haha!! That is a very interesting failure mode indeed. I'm guessing that because of their plate growth, the actual plates get ripped off of the internal busbars. I have seen that in old automotive style batteries that I have torn apart for science :P Don't worry, I have proper safety gear to do that sort of thing! And yeah, heat is no good for batteries. It can cause pretty severe internal corrosion due to overcharging too, if the temperature compensation of the charging gear is not adjusted properly. Although adding to that... Right now in my solar powered house I have 3 old starting batteries currently, which two of are approaching 8 years of age... They have a surprising amount of capacity for what they are, Obviously not anything to brag about but they have no problems running my 180 watts of fluorescent lighting for 4 hours or so! they are not even fully drained after, but that's usually as much time as I spend out there working on projects in a evening! That's about 720 watt hours used, probably a bit more since the inverter is not 100% efficient obviously. so say 800 watt hours every evening :) Plus I may use soldering irons and other stuff, so it can vary. I think I should thank my fully adjustable temperature compensated charge controller for that! It becomes 30-40C in there, when the sun hits hard. But the batteries stay relatively cool anyways, they are not very high up in the air so that helps. they rarely get above 27C. I also find it very interesting how those 6V blocks hold up so well! My guess is that they were treated perfectly in their past life, and knowing you, I know you are treating them even better now :3 They seem wonderful! Next time, you should try to only get those... They seem way better than anything else! That is interesting to know! I still have not heard a thing from them, but that could explain why! That calms my nerves a bit, as I was worried for a moment that something had gone seriously wrong with my order. It is of course also possible that my order is not very prioritized since I only bought one battery for now, since they are so expensive. I plan to buy another one a few months later, which should not be a problem with these since they last so incredibly long. I definitely will grab them if I can! I know they are not very reliable, but hey, free is free! :D If I can get 2 years of cyclic use out of them, I will be more than happy.

[@tigerelectronics5966]

@FFcossag My sonnenschein battery arrived today!! It made it in one piece! Now comes the matter of transporting it to where I want it... hehe

[@FFcossag]

Fun times.

[@tigerelectronics5966]

@@FFcossag It was one hell of a challenge, had to build a new battery rack and everything but it is done now :) It is in service as we speak. Can't wait to get more of them, I did some load testing last night and oh boy, I could not get the voltage below 12.38V even with pretty decent load, for a really long time aswell! Talk about an upgrade compared to old shitty automotive style batteries! :D

[@FFcossag]

I'm glad it worked out. Just remember to configure your charge controller for a pretty low bulk and float voltages. A600s seem to live longer if slightly undercharged than if slightly overcharged; you can recover from sulfation due to undercharging, but you can't recover from corrosion due to overcharging.

[@tigerelectronics5966]

Me too! I am super happy that it all went well with shipping, and moving it into place here at home :) I did hurt my back a little, I found out a few days later... So definitely need to come up with a better transporting solution when I get more of these in the future. Indeed, that's what I suspected aswell. You can always recover sulphation, but never get lost electrolyte and you can't undo corrosion... The sonnenschein handbook says that a float voltage of 13.5 and a bulk charge voltage of 14.1 is recommended for a fairly wide temperature range. I've adjusted my float voltage down to 13.4, I've left the bulk and absorption voltage around 14.1 though. My charge controller is fully temperature compensated too, so I've set up a fairly aggressive temperature compensation curve since it can get a bit hot in my solar shed sometimes. Although I've been pleasantly surprised how cool the battery is staying, since I've placed it as close to the floor level as possible. It hasn't exceeded 25°C so far! So I most likely don't need such an aggressive curve. But I'd rather undercharge it slightly than over charge it accidentally like you said. My controller also has a tail current setting, (basically a amperage threshold where it switches from absorption to float charge), I decided to set that fairly high so it doesn't sit there blasting the battery with 14.1V when it's basically nearly at 95+% state of charge. I set the tail current to 3 amps, I'm unsure if I should set it even higher to make it switch to float sooner. I'm also unsure about how often I should let the charger do equalizing. I set the equalizing voltage to 14.4, as recommended by the datasheet. (Seems a bit low to me?) And one hour, every 30 days. I can't really find any good information about whether or not that's too often? Or too long in-between? Also not sure if 1 hour is too short or too long :P So I definitely have some questions left unanswered hehe.. gonna take a good moment today and read through the entire handbook, because today is finally a calm day for me. I've read 90% of it thoroughly, but there's a few pages of information left. I also have conflicting information about terminal torque, the handbook says 20nM, and the battery itself says 12nM on it. I went for 20 because 12 seems awfully loose to me, if I bump the wires or something (I have 35mm2, not super fine stranded, so a bit stiff,) they become undone with just 12nM. Nothing seemed to be flexing or anything tightening them to 20, so I highly doubt I've caused any damage to the battery. I just got a bit worried about that since you mentioned your cells having been over torqued and leaking, but I suspect yours were *severely* over torqued, such as someone using a impact driver.... Anyways hehe, this reply just became insanely long:P Also wondering if I could talk to you some where else, because KZbin comments is incredibly glitchy and it seems to randomly delete my messages... I could email you instead, that might be easier! I also have discord which could maybe be a bit more practical, then I could show you things more interactively and show photos and video clips x3 (also I'm making a YT video about the battery, so expect to see that soon ish!)

[@FFcossag]

You can find me on Discord, ff_ccsa1f 14,1 and 13,5 are good voltages. I wouldn't do 13,4 since that's basically nothing at all. Sonnenscheins don't "need" temperature compensation, but they still benefit from a gentle slope. 0,001-0,003 V/Cell/degree doesn't hurt. Install your temperature probe on the negative terminal of the battery since it'll get warm if you're overcharging. 14,4 V is a good equalising voltage, but you should run it for 6 hours or so. My experience tells me that a less frequent but more aggressive equalisation cycle is preferable. I only equalise my batteries a few times a year unless something has happened (which also happens a few times a year). 3 A is a very high float transfer voltage for such a small battery. I'd do no more than 2 A, but this also depends on how much useful charging per day you get. The less charge time per day you get, and the deeper a daily cycle you pull, the more aggressive your lower absorption current limit needs to be.

[@brookerobertson2951]

Soon will be time to take it to the dino 😂😂😂

[@FFcossag]

Hehe, I don't think a dyno would even register it ... The absolute peak power it'll put out is about 19 horsepower, closer to 12 if you're actually trying to do 70 km/h. :D

[@craignehring]

Always enlightening Did the diesel expire or is it going to be a rolling charging station?

[@FFcossag]

Thanks! The diesel is alive and well and just waiting for spring so the neighbour and I can move it without his loader sinking into the ground. I hope I'll be able to film a few videos about it when the project starts up for real.

[@playdav485]

hi i recommend writing in a book / journal information about the car/mods for future reference eg wire connection and function it can be very useful especially if you have not altered it after 2+ years

[@FFcossag]

I actually do write a lot of it down in a little notebook I keep in the car! A lot of this mess was just considered so temporary and simple so as not to require documentation, which is still true. It was a hackjob to keep it on the road while I was figuring out what to do.

[@SudosFTW]

So with the fans, PWM control is nice, but it may also be an idea to have the fans do their own speed control based on temperature. Nidec makes the Beta V line, or did, and the TAxxxDC line had options with thermistors. Dell used these extensively in their Pentium 4 towers before moving to PWM control in 2005. The 92mm options are extremely resilient little bastards and I've had the ones in my case in many a PC, and have been in service for nearly 20 years at this point with minimal interruption. Still sound like the day they came out of the factory. They get super hella fast and loud at full tilt if you short the thermistor, and while PWM is nice, it might be more of a "keep it simple stupid" approach to configure a relay to short the thermistor on such fans to run at full tilt in the case of excessive heat where the thermistor isn't doing the job. but, that might be the case on very hot days or the like. They run at one set speed around 1000rpm otherwise. I retrofitted one such fan into an OptiPlex GX400 as the fans those came with were the ill-fated JMC Datech fans that blow their bearings and sound like a cat scratching against a chalkboard constantly. The wiring, in time, can be cleaned up once you have shielded what needs shielded, but beware the very very cheap spiral cable glands that might help tidy the mess-- a lot of them have a coating or something in the plastic that smells like rotten flesh + vomit when it offgasses with age. Velcro cable ties are a big must here, no zipties unless it's deemed absolutely permanent as you go through your board revisions. What you're doing here is nothing less than captivating. This can not only help owners of these vans but many, many more cars with such a system.

[@FFcossag]

Good old Nidec fans, I have a few lying around the shop as well. And thank you - I only wish I'd been able to continue the project the better part of a year ago.