Keyboard Shortcuts
Likes
Search
Re: Time to re-power >> How many cells??
¿ªÔÆÌåÓýAnd some of us use 12¡though a different chemistry. My Enerdel pack batteries are not LiFPo. Voltage range: 2.5 - 4.1vpc (pack: 30 - 49.2v) Nominal Pack Voltage: 42v ? That worked out well for me as I upgraded from 36v flooded PbA and didn¡¯t have to change my controller or 36-12v DCDC. Charger¡¯s a different story¡ ? -MT From: [email protected] [mailto:[email protected]] On Behalf Of john via groups.io
Sent: Wednesday, June 3, 2020 12:47 PM To: [email protected] Subject: Re: [electricboats] Time to re-power >> How many cells?? ? So are you saying some people use 15, and some use 16? ? Obviously, 16 would give you a little more power, with more expense.?? Is there a common trend one way or the other? ? I've been playing with an EBike battery pack from BTR.? ?"48V, 20Ah".? ?But no solid documentation on how many cells.? It's supposed to be LiFeP04.? The charger seems to be topping out around 57V.? Resting voltage after unplugging the charger is about 56V, and then it quickly drops down to 51/52V when a small load is applied.? ? I'm guessing this is a 16 cell battery.? ?But won't know absolutely unless I take one apart (which won't happen until I kill one.? <grin>). ? John ? On Wednesday, June 3, 2020, 02:32:21 PM CDT, L Schmitz via groups.io <terminalift@...> wrote: ? ? Hello John,?? Good questions.? ? Most 48v hardware has 60v capacitors inside so you can max out the voltage close to 60. With 16s it can reach 58.4v. 15s can be used as well. Will have a lower voltage cutoff but the device wont provide a redundant low voltage protection as it thinks it's got a 48v battery. So in short... it can be used just needs excellent monitoring and it only has 1 protection from over discharge ? I hope this helps? ? thank you? kind regards Larry Schmitz ? ?Terminalift LLC 9444 Mission Park Place Santee, CA 92071 Ph: (619) 562-0355 F: (619) 562-2060 ? ? On Wednesday, June 3, 2020, 10:41:41 AM PDT, john via groups.io <oak_box@...> wrote: ? ? Silly question...? ?Though I hope to get several answers! ? Why 16 cells? ? These are 3.2V nominal cells, right? They charge up to 3.65V, and can discharge down to 2.2V?? ? So, to give plenty of margin, maybe run between 2.75V for a low, and max of 3.5V? ? For 15 cells, that gives:? 41.25 to 52.5. For 16 cells, that would be:? 44 to 56V ? It would seem like the 15 cells hits the 48V range easily enough. Are people rounding up to 16 cells just so that they have an even number to work with?? As one example, the Torqeedo 4R has a lower limit cutoff (assuming Li and not lead) of 42V (lead setup is 36V) - so a 15 cell configuration would work reasonably. ? Just curious what the thoughts were here. ? Thanks, John ? On Wednesday, June 3, 2020, 12:13:25 PM CDT, L Schmitz via groups.io <terminalift@...> wrote: ? ? Hello Fred,? The 48 v? 90 ah pack is pretty easy to assemble. That will be 16 cylinders.? You can fit them in 1 West Marine heavy duty battery box.? Weight will be about 85 lbs.? ?Just assemble bus bars to place in series. Then add a bms? and charger. I will check costs on these and forward to you. thank you? kind regards Larry Schmitz ? ?Terminalift LLC 9444 Mission Park Place Santee, CA 92071 Ph: (619) 562-0355 F: (619) 562-2060 ? ? On Tuesday, June 2, 2020, 05:27:23 PM PDT, fred jelich <freddyj408@...> wrote: ? ? I'd be interested in 48v? 90ah for my boat! ? On Tue, Jun 2, 2020, 5:15 PM L Schmitz via <terminalift=[email protected]> wrote:
|