If you have a bike with no BMS and you are monitoring the cells that should be all the data you need to decide if a BMS is necessary. Not what others tell you.
What are you observations of the cells Sent from my iPad > On Jun 23, 2015, at 6:29 PM, damon henry via EV <ev@lists.evdl.org> wrote: > > > > > > > Thanks Cor, for the information. I thought I would like to play with these, > but maybe not due to some of the concerns you bring up. > I currently have 16 60ahr calb cells I am learning with on my motorcycle with > no BMS. The investment in this small of pack is not huge and hands on > learning is worthwhile, so I don't mind being my own BMS in this case. I > would eventually like to put Calb cells in my truck. I will likely install a > BMS in my truck as that will be a larger investment and more cells to try and > keep track of manually. Right now I am leaning towards Orion. So the Zener > balancers were just going to be for experimenting and observation. > I understand the risks of not installing a BMS, but it is always interesting > comparing that against the risk of having something permanently wired across > your cells. > damon > >> Date: Tue, 23 Jun 2015 11:18:42 -0700 >> To: ev@lists.evdl.org >> Subject: Re: [EVDL] Lee Hart Zener Regulator for Calb cells >> From: ev@lists.evdl.org >> >> Lee has discussed this in the past, it is likely in the archives. >> I see three main issues: >> - at lower voltage, the zener knee gets very soft so unless you use >> additional electronics to amplify, the zener itself does not work very well >> on a single cell as you already indicated, two cells might indeed be better >> since around 6V the zeners have the best characteristics but that introduces >> issues with imbalance between the two cells >> - Voltage differences while charging are very small with most types of >> Lithium. 3.2V at rest but 3.5V is over-charging a LiFePO4 cell whereas a >> flooded/AGM lead-acid battery can easily go from 12V to 15V and it does not >> hurt them to be sitting at 15V while balancing for an hour. >> - leakage and failure: while zeners are supposed to go "on" at a certain >> voltage, they will leak below that voltage so you are introducing extra >> "self-discharge" which can very per cell with the properties of the zener, >> so in a sense you are making the situation for Li-Ion worse. Also zeners can >> fail (shorted typically) and mechanically fail and the Lithium cells will >> not take well to being over-charged due to a failure >> >> Cor van de Water >> Chief Scientist >> Proxim Wireless >> >> office +1 408 383 7626 Skype: cor_van_de_water >> XoIP +31 87 784 1130 private: cvandewater.info >> www.proxim.com >> >> >> This email message (including any attachments) contains confidential and >> proprietary information of Proxim Wireless Corporation. If you received >> this message in error, please delete it and notify the sender. Any >> unauthorized use, disclosure, distribution, or copying of any part of this >> message is prohibited. >> >> >> -----Original Message----- >> From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of damon henry via EV >> Sent: Tuesday, June 23, 2015 10:37 AM >> To: EV List >> Subject: [EVDL] Lee Hart Zener Regulator for Calb cells >> >> Hi, >> I am wondering if anyone has adapted Lee Hart's Zener regulators for lithium >> cell use. I don't think the voltage of one cell is high enough to use this >> type of device on, but I think proper values can be found to regulate two >> cells in series. I would love to experiment with some of these and would >> like full bypass at 6.8 volts. I believe the 12 volt model can be tweaked >> by picking appropriate replacement Zener diodes, but I don't do a lot of >> this type of design, so I am not familiar with what is available or where to >> source the parts. Any help would be appreciated. >> thanks Damon >> Here is a link to Lee's >> design.http://www.sunrise-ev.com/LeesEVs.htm#zenerlamp >> >> -------------- next part -------------- >> An HTML attachment was scrubbed... >> URL: >> <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150623/2b159354/attachment.htm> >> _______________________________________________ >> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub >> http://lists.evdl.org/listinfo.cgi/ev-evdl.org >> For EV drag racing discussion, please use NEDRA >> (http://groups.yahoo.com/group/NEDRA) >> >> _______________________________________________ >> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub >> http://lists.evdl.org/listinfo.cgi/ev-evdl.org >> For EV drag racing discussion, please use NEDRA >> (http://groups.yahoo.com/group/NEDRA) > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20150623/212b619a/attachment.htm> > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > For EV drag racing discussion, please use NEDRA > (http://groups.yahoo.com/group/NEDRA) > _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
