Good points Jay. I'm concerned with Peukert's law but if I could perform under similar loads it would mean more to me and less to stated ah. Both would be ideal I guess- one for me and one for the evdl list. But maybe I'm the last guy here running lead so results given back wouldn't be of much value here lol.
Thanks Dan On Wed, Mar 13, 2019 at 4:46 PM Jay Summet via EV <firstname.lastname@example.org> wrote: > I think it would be better to measure at a higher amp rating if > possible. (Make your test go faster, and more accurately model the true > draw on the battery under load). > > How many amps will the batteries see under your particular usage > scenario? If you can replicate that same amp draw (either with lots of > lights, a big resistor in a bucket of water or whatever....) it would > probably be the best test for your situation. (Plus, if the amp draw is > higher, the precision of the amp meter would matter less....) > > Jay > > On 3/13/19 3:38 PM, Dan Baker via EV wrote: > > Thanks guys- never thought of this, I have a similar unit in my boat > > already. I typically use it just for monitoring amp output and volts. I > > have two throttles on my boat, a spring loaded Curtis-PB6 which I use for > > docking/ maneuvering and a 5k knob style pot that I switch over for > > cruise control, set the pot for desired amps/speed off of the gauge. I'm > > not sure if it will accurately pick up a small 1 amp load as it is rated > > for up to 400 amps. Anyone share what they used for a test load- a > > resister or a bulb? I assuming around 1 amp (12 watts) will be closest > to > > measuring true a/h readings. Given that these lithiums only charge to > 12.6 > > volts means my cut-off voltage will likely be closer to the stated BMS > > cut-off, somewhere between 9-10 volts or when the voltage starts sharply > > falling off? > > > > On Wed, Mar 13, 2019 at 3:23 PM John Lussmyer via EV <email@example.com> > > wrote: > > > >> On Wed Mar 13 11:06:36 PDT 2019 firstname.lastname@example.org said: > >>> Yep Totally agree. I use several of these to monitor voltages and > >>> currents in my DIY EV. Nice thing about them is that they work both > ways > >>> and will take into account regen and charging as well as discharge. I > >>> found them to be as accurate as shunt based meters at a similar price > >>> range BTW. > >> > >> I use this one: > >> > >> > https://www.amazon.com/Programmable-Digital-meter-battery-monitoring/dp/B0043BDFYA/ref=sr_1_1 > >> > >> has 2 relay outputs, counts AH in both directions, uses a shunt for > >> currents over 5A. > >> I've found it to be pretty accurate. > >> > >> > >> -- > >> > >> Try my Sensible Email package! > >> https://sourceforge.net/projects/sensibleemail/ > >> _______________________________________________ > >> 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/20190313/3f48978c/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) > > > _______________________________________________ > 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/20190313/eba97465/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)