Energy storage - New gen batteries

smkettner wrote:

NinerBikes wrote:
Would bouncing around in the middle 80% be true also for smart phone batteries?

Sure but the device may still be obsolete before the battery dies. Actually it depends on the device BMS as it might already be programmed to use the middle 80%. It does speak for not letting a device sit empty for extended periods or plugged in continuous.

I'd think on cell phones, that most people burn that battery up within 500-1000 near 80-90% DOD's, power users on smart phones are power hogs that can't even make it to 5pm before needing a partial recharge. This was quite common all over the Consumer Electronics Show in Las Vegas last week, folks clambering up to 120V electrical jacks for life blood for their Apple phones. Me, I run a fat back 2650Mah on my Galaxy S4 to get through those power use days unscathed.

Good points though, I suppose indicated " 100% SOC" voltage could be measured on the battery with a DMM to confirm Voltage it was charged to. 4.21V is about max for 18650's I run in flashlights and such.

NinerBikes wrote:
Would bouncing around in the middle 80% be true also for smart phone batteries?

Sure but the device may still be obsolete before the battery dies. Actually it depends on the device BMS as it might already be programmed to use the middle 80%. It does speak for not letting a device sit empty for extended periods or plugged in continuous.

Dakota98 wrote:
ONLY 252 Lbs. !!!! :S

Well, lead acid would be what about 100 pounds per usable KWH or 50 pounds per total KWH (Somewhat rounded on both numbers) and this is a 9KWH battery

So yes, 252 pounds is in the neighborhood of 1/4 what that much Lead would tip the scales at.

And at 4 grand... About 4/1 the price of that much lead.

Standard 9 V batteries can supposedly catch fire if two of them are placed together with their contacts touching improperly. There was a Youtube presentation on this that went viral recently.

Smart phone batteries are probably lithium cobalt for their higher energy density.
Reed and Elaine

smkettner wrote:
The BMS will cut power before the damage occurs. I believe the BMS will allow 100% DoD based on capacity and staying above that minimum voltage. Voltage will get into that curve toward the bottom but the cut-off is complete as the contactor opens. Not the same as a brown out as your 12v flooded battery goes below 11 volts.

The best part is you can keep your solar producing max all day as the lithium battery does not taper charging anything like the flooded battery. And no need to ever get to 100% to preserve battery life. Yes bouncing in the middle 80% of capacity is best for longevity on a lithium battery.

Would bouncing around in the middle 80% be true also for smart phone batteries?

X2 smk

horton333 wrote:
Places like Tesla, one of the highest tech car companies in the world, still get fires in their cars from time to time and so does every laptop manufacturer out there. Tesla use titanium shields to protect people, they know the hazards. They have extremely advanced charging and temperature monitoring systems, yet still some catch fire. I think they are the way of the future, but I would not go in without investigating the very real issues and making sure the risk is contained.
I note the smaller batteries they advertise seem to have more built in safeguards than this one, may be a better choice. Not sure.

I think that Only time Tesla batts caught fire was due to damage in a road accident when these cases ruptured
not overcharging or spontaneous combustion

The BMS will cut power before the damage occurs. I believe the BMS will allow 100% DoD based on capacity and staying above that minimum voltage. Voltage will get into that curve toward the bottom but the cut-off is complete as the contactor opens. Not the same as a brown out as your 12v flooded battery goes below 11 volts.

The best part is you can keep your solar producing max all day as the lithium battery does not taper charging anything like the flooded battery. And no need to ever get to 100% to preserve battery life. Yes bouncing in the middle 80% of capacity is best for longevity on a lithium battery.

Agree with Mena661. The plots seem to merely show the extreme drop off at 90% DOD with LFP that has been extensively discussed. This is why it is strongly suggested that one not drop below 80% DOD with LFP. I think most people consider Peukert effect with consideration of charging a battery bank. We have found that such charging is almost linear with our LFP battery bank.
Reed and Elaine

PT see my previous changed post. Another thing, you won't see that drop off until ~90% DoD. There is SOME Peukert with LI just not enough to notice (it's very near 1).