Hi Dan and All, A solar boat is likely in my future too. The voltage are normal for that type of cell, 49.5vdc top and 36 though under 39vdc, there is little energy left as it drops off a cliff. So I'm using 39vdc as my lower cutoff though manual, it can be done by the HB404 too as has 2 programable if harder than hell relay drivers. I just use power supplies set to 49.5vdc for charging now and using a MPJA 100vdc, 100amp wthr meter to just keep track. Steve has a good point but something anyone should be thinking about when designing a system what might happen. Running it off 48vdc means both can go down together too. But each system is different. I'm not running any BMS as most don't as too much an expensive PITA. And the quality of the cells seem to not be needed at first. After it ages could be another matter. There are some interesting low cost bike BMS chips that could work at 48vdc. A 4kwh module is 2 48vdc sections, 5 kwh has 2 48vdc and a 12vdc sections, a 7 kwh has a 12vdc and 3 48vdc sections though that has changed in recent packs. But few of them are out there yet, most being 2012-2014 model yrs. And heavy at 25lbs./kwh. But cheap, powerful. On a boat I'd keep it at 48vdc for shock hazard unless no other choice . If I were you charging from the grid I'd just buy a settable powersupply for hands off and use your lead chargers as bulk charging with a timer doing most of it, and the PS finishing it off is how I'm , most are doing it. I'm looking for surplus/cheap 1-4kw 48vdc power supplies myself and exactly where one can find used 48vdc 2kw and up UPS systems? . Jerry Dycus
From: Dan Baker via EV <ev@lists.evdl.org> To: Electric Vehicle Discussion List <ev@lists.evdl.org> Cc: Dan Baker <vmd...@gmail.com> Sent: Saturday, May 26, 2018 8:47 AM Subject: Re: [EVDL] Lots of 12v lithium batteries available. This a great relevant thread for me. I'm interested in going from Lead to Lithium on my boat and I believe Volt cells are likely the most available and least expensive to me. The Volt cells appear to have different charge points than most Lithium so the HB404 looks like a great solution. Jerry, do you just use one HB404/ contactor for a string of cells that add up to 120v when charged? No other BMS? I'm looking at doing 96v setup, doubling my current 48v setup. I was thinking 2 x 48v packs, 2 HB404s and contactors and using 2 x 48v chargers that I already own. Appreciate any advice on this, excited to switch to Lithium but nervous of destroying a set in the learning stage lol. Cheers Dan On Thu, May 24, 2018 at 1:36 PM Len Moskowitz via EV <ev@lists.evdl.org> wrote: > Thanks Jerry, but I'd like to keep the lead-acid form factor and use the > existing charger. > > Len M. > > ----- > On Thu, May 24, 2018 at 12:30 PM, jerry freedomev wrote: > > > > Hi Len and All, > 2 5kwh, 120vdc nom Volt modules would by far be the best, > lowest cost solution. And for charging just add an HB404 wthr meter and > a contactor to cut the voltage off at fully charged using your present > charger likely. > Each take about the same space as 2.5 of your 12vdc lead > batteries. And cost $1500-$2300 buying modules, not much more than > lead, less than premium lead. > Since 2 modules will put out 2k amps and weigh much less, > lead EVs I've sold them for nicely increase both range and pickup even > with the same rated kwh. And one can add another module or 2 for more > range. > My rebuild of my EV trike pickup into the subcar it was > suppose to be I'll put 2 5kwh modules in it for about 120 mile range. > Could put in 250 miles worth. > Jerry Dycus > > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180524/aa8062a4/attachment.html > > > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Please discuss EV drag racing at 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/20180526/d2ab40a6/attachment.html> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at 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/20180526/a620d567/attachment.html> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)