โJan-26-2018 12:32 PM
โJan-29-2018 11:50 AM
brulaz wrote:
Battleborn says that while you can charge up their LiFePO4 cells at lower voltages, maybe as low as 3.4V per cell (13.6V for 4), you want to go higher to *balance* the cells, up to their recommended 14.4-14.6V. The balancing is strictly a BMS function and the BMS balancing procedure controls the individual cell voltages.
So what happens if you have only weak solar or alternator V's that never get up high enough to balance the cells? ๐
brulaz wrote:Could be poorly controlled experiment, SOC way below 100%. Hard to tell without knowing the details.
on another forum there's a guy who said he can still pump 20A into a 300Ah LifeBlue battery after it reaches 100% SOC and his charger's V drops below 14V (EDIT: actually his weak solar charger never gets up that high)
โJan-29-2018 09:14 AM
landyacht318 wrote:Battery specs
The one pic shown appears to have a bunch of 18650 or some other type of cylindrical size cell.18650 cells are not Lifepo4 but Lithium colbalt or Limaganese.
โJan-29-2018 09:10 AM
โJan-29-2018 09:00 AM
pianotuna wrote:
Brulaz,
All the reading I've done suggests that LI do not wish to be floated.
I've gleaned that 90% soc is going to give the best results, and that 20% is as low as you wish to go.
The question becomes does the maker "code" that into the battery management system? To me that would make the most sense.
โJan-29-2018 08:38 AM
โJan-29-2018 06:19 AM
pianotuna wrote:
Brulaz,
All the reading I've done suggests that LI do not wish to be floated.
I've gleaned that 90% soc is going to give the best results, and that 20% is as low as you wish to go.
The question becomes does the maker "code" that into the battery management system? To me that would make the most sense.
โJan-29-2018 06:02 AM
โJan-29-2018 04:04 AM
Almot wrote:brulaz wrote:
... will get you you to ~95% SOC soon enough and allow cell-to-cell balancing. And just about any 1 or 2 stage charger with an AGM setting, or even an adjustable V Meanwell cc/cv power supply should be able to do that.
... as long as it's able to terminate charging at this point (or, better yet, few % below). These chargers will keep it in Absorb where you may not want to be, and/or drop to fixed Float where it "should" terminate charging, but I recall some reports few pages ago that it doesn't always stop charging in Float. Can anybody provide a link to that discussion, btw?
You want to be able to adjust charging profile. Meanwell looks better in this respect. Perhaps, coupled with $3 kitchen timer.
...
โJan-29-2018 03:19 AM
2oldman wrote:brulaz wrote:58.4 is the bulk charge end voltage.
2Oldman had a couple of Schumacher chargers modified for his 48V LiFePO4 battery bank. Is that 16 cells in series or ?
Curious what V they get up to: 3.65x16=58.4V ?
You tell me! I think there's a couple stacks of these cylinders.
โJan-28-2018 07:34 PM
2oldman wrote:
You mentioned you could us an extension cord with AGM, but you had to take the Li in to a "wall charger"? Is that something permanently attached to a wall?
landyacht318 wrote:
One think I wonder about is the OP's Kill a watt readings.
80 watts for a laptop is fairly high. My laptop is an older dell that requires a 90 watt adapter, but if the battery is already full, it uses about 30 watts to type this.
โJan-28-2018 04:32 PM
brulaz wrote:
... will get you you to ~95% SOC soon enough and allow cell-to-cell balancing. And just about any 1 or 2 stage charger with an AGM setting, or even an adjustable V Meanwell cc/cv power supply should be able to do that.
โJan-28-2018 02:34 PM
brulaz wrote:58.4 is the bulk charge end voltage.
2Oldman had a couple of Schumacher chargers modified for his 48V LiFePO4 battery bank. Is that 16 cells in series or ?
Curious what V they get up to: 3.65x16=58.4V ?
โJan-28-2018 12:32 PM
โJan-28-2018 12:17 PM
grizzzman wrote:
...
This info if used will put an end to lfp much sooner. Never subject the cell to hit 4.2 volts.