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06-05-2019, 06:44 AM | #1 |
Gone Wild
Join Date: Sep 2012
Posts: 245
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Please review my buy list for lithium build
I just purchased 10 Leaf modules for a 72v conversion. I have been in touch with Ian to purchase a Zeva BMS. I plan to purchase:
1) EVM53 which should work (2x12 cell)?? 2) Optionally some kind of CAN current sensor (no clue, but would like it to be done right) 3) 72V-12V step down converter (will take out my 12v accessory battery) 4) Optional EVMS Monitor 5) TC Charger (HK-H-H99-25 recommended but sold out from Aliexpress) Assuming I can figure a way to assemble to batteries and for a collective batter pack, is there any other items I would need in addition to whats mentioned above? Thoughts on using plywood or metal for end plates to sandwich the plates together? How tight should I squeeze them? Thanks! |
06-05-2019, 07:31 AM | #2 | |
Gone Wild
Join Date: Jul 2018
Location: Central Ohio
Posts: 1,720
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Re: Please review my buy list for lithium build
Quote:
I won't comment on the ones I don't know about 4) I would definitely get one. The question is, do you want a dash mount or panel mount. 5) Get in touch with DaveTM. He went through a bit of a dilemma with his and can give you advice on how to order it to make sure it is set up correctly for you. Unless it is built into the EVM53 you will need a shunt or hall effect sensor. I don't believe it is built into the EVM53, but don't know for sure, it's not built into the EVMS that I have. From what I have seen the only real benefit to use hall effect over shunt, is less cables... (again, wait for the gurus to confirm) You will want to have a LV/HV cutoff of some sort, assuming that the EVM53 does not do this by way of software. You can either go with a contactor or relays. Zeva does sell contactors, you can also buy them directly from a manufacturer. The use of contactor from all of the builds I have seen is more expensive than relays, but easier to wire in my opinion. I went with a contactor. I would not use plywood. As to how tight to compress them, there is not a set amount that I have come across. Did the batteries you ordered come with the side plates? I used 5/16" allthread and just tightened until "it felt right". If you got the 2nd gen modules, they have metal sleeves where the allthread goes through, you really can't overtighten them. I don't think the 1st gen modules have the metal sleeves, I don't know about the 3rd gen modules. Hope this helps. I'll be following along and offer what advice I can as well as learning about the higher voltage setup. |
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06-05-2019, 08:09 AM | #3 |
Gone Wild
Join Date: Sep 2012
Location: Charlotte, NC
Posts: 9,329
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Re: Please review my buy list for lithium build
I never heard of a EVM53, Zeva has an EVMS3 Controller but you will also need two BMS12v3 to actually balance the cells.
The EVMS monitor is pretty much mandatory for your setup or you will not be able to configure it properly. Leaf cells need to be under compression the entire time they are charged or discharged to avoid failure. The four threaded rods do not apply pressure directly on the pouches, the unique tray shape of the case acts as a "spring washer" to provide the proper compression inside the modules. It is important that if your particular modules came with any spacers that they are installed as to preserve the original width profile. When properly torqued and compressed the distance between adjacent modules power taps should be 1.3333". I have seen lots of designs online (and some in this site) where plywood is used for end plates, it is your choice. |
06-05-2019, 08:19 AM | #4 |
Gone Wild
Join Date: Aug 2008
Location: Leander TX
Posts: 166
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Re: Please review my buy list for lithium build
You get first gen modules? Techdirect has the end plates and spacers if you want to buy from them. I found the asking prices for the end plates and spacers to be ludicrous, so I made my own. I couldn’t bring myself to waste that much steel plate so I used some 3/4” ply for end plates and stacked washers for spacers. There are sleeves in the first gen modules as well to limit compression when you put it together. First gen spacers should be close to .143”. Here’s a pic of when I first got my modules and I absolutely HAD to put them in the cart and run down the road, ignore my layout as it was temporary. Plywood end plates are still being used and working fine.
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06-05-2019, 08:36 AM | #5 | |
Getting Wild
Join Date: Aug 2015
Location: Conroe/Woodlands, TX
Posts: 133
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Re: Please review my buy list for lithium build
Quote:
Trying to get the small parts from Tech Direct is ridiculously expensive individually. Even on the auctions that “include” the plates. I never got them and they refunded me a portion. I am fine without them in the long run. Sent from my iPhone using Tapatalk Pro |
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06-06-2019, 02:02 PM | #6 |
Gone Wild
Join Date: Sep 2012
Posts: 245
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Re: Please review my buy list for lithium build
Thanks all. Yes, 1st Gen Leaf batteries. Still sorting out what to get from Ian.
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06-06-2019, 03:33 PM | #7 |
Gone Wild
Join Date: Oct 2012
Location: Southwestern Pa.
Posts: 6,214
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Re: Please review my buy list for lithium build
If your going with the "CAN Bus" charger like this one https://www.elconchargers.com/catalo...0/10295151.htm then I would advise buying it from Electronic Conversions in California. (The link)
They will program it properly so you can do your charging parameters with the ZEVA. I purchased mine from China and thought I was getting one set up for making changes.....but they sent me one "hard-wired." I then sent it to the California guys to make the changes. The monitor is really a must for the ZEVA. The contactor setup is somewhat expensive. I went with relays as they are just as effective and much less $$$. |
06-07-2019, 06:42 AM | #8 |
Gone Wild
Join Date: Sep 2012
Posts: 245
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Re: Please review my buy list for lithium build
Thanks so much DaveTM, not sure what you mean about the contactor/relays. But I do appreciate the charger advice. I will get it from there. Trying to keep the price low, but also realizing my lack of knowledge so support and having all the pieces working nicely together is important. Ian seems to be taking care of what he can provide and he does seem very helpful.
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06-07-2019, 09:50 AM | #9 | |
Getting Wild
Join Date: Aug 2015
Location: Conroe/Woodlands, TX
Posts: 133
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Re: Please review my buy list for lithium build
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I believe he is referring to the actual devices that allow the bleeding off of an over charge or allow balancing to take place. I am sure he will explain it more clearly. Sent from my iPhone using Tapatalk Pro |
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06-07-2019, 08:40 PM | #10 |
Gone Wild
Join Date: Oct 2012
Location: Southwestern Pa.
Posts: 6,214
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Re: Please review my buy list for lithium build
For the HV (High Voltage) and LV (Low Voltage) cutoff's I purchased these relays from Mouser electronics: https://www.mouser.com/ProductDetail...rrencycode=USD At $5.68 each....way less costly than the big contactor that ZEVA sells.
As for the "hook up" of the relays....take a look at this setup (my setup) and if you have questions please ask. |
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