Hi All
Just swapped out the "lion" battery in my cell phone. It would inexplixebly self discharge it's self over a 12 hour period. Developed this problem off and on for the last two years. New repacement battry does not do this - doesn't seem to be a phone/operator problem.
My previous cell phone 4 years? ago on the first out of the box phone would overheat badly on charging. They of course walk in replaced the whole phone, battery and charger on that one so I'd forgotton about it. That phone got lost some-where. Pocket fall out when I was out rough ground mowing I think. Ha! Not the battries fault.
Between the wife and I in current personal elecronics and my last purchased cordless drill we now have six LI-ions now versus the earlier used NiM-Hyd and NI-Cads.
Had a couple of NiM-Hyd packs just go open circut. The NI-Cads always had a PITA charge memory problem requiring constant full dischage/charge awareness to get usable life. Same problem I've had with all of my lead acids vented and sealed.
Given the current DreamLiner problems and some reported laptop overheats LI-ions seem to work well when they work but be very difficult to manufacture consistently. Latest news now is many having to be replaced out for undercapacity/charge up abilty before the melt down incidences.
Any of you newer Hybrid vechicle drivers concerned about this? Big high wattage banks there. Had any recalls about your newer battery banks?
Regards
Steve Unruh
Last I heard Boeing anf FAA have given the battery manufacturer a pass in their production. The investigation has moved to the charge/usage controller that may be driving the batteries into a fault region and causing them to cook off.
All batteries are hazardous in that they contain a huge ammount of instant energy. Lithium-ion batteries are more sensitive to their charge/discharge regime and can be driven to failure or fire easier than say a ni-cad or lead-acid.
Havn't heard of too many hybrid failures. The ones I have heard of have had to do with issues arising from plug in kits added to hybrids such as the Prius to allow them to charge overnight in the garage so you spend more of your daily commute on battery power...
look at the rc communety on rc groups .
I fly with max 500 watts on my rc plane,s but there are 5000watts planes .
Lipo,s are safe as long if you take care at max volts and the min voltage on the packs .
The discarge amps are realy greate butt as always use them ore loose them .
Leave them onused and they can degrade .
I use sometime,s one to start my sisters scooter 150 cc four stroke on a 500 gram heavy 11,1 volt lipo 5000mah discarge max 200 amps .
I'm curious to hear about any Li-Fe users experience those bats. Eventually the 48kw FLA battery bank for our home will need to be replaced and it looks like these would work and the bank could be a lot smaller too.
Quote from: Tom on February 03, 2013, 08:29:17 PM
I'm curious to hear about any Li-Fe users experience those bats. Eventually the 48kw FLA battery bank for our home will need to be replaced and it looks like these would work and the bank could be a lot smaller too.
I think the entire Li-nnn line, needs to have individual monitors for each cell, along with thermal management (Thanks Boeing Aircraft, for bringing battery thermal management to our attention) for the battery pack. They need heaters for when they are cold, and coolers for other times. I hope my Ni-Fe bank lasts me long enough (I've heard bad things at the 10 year mark as the Chinese did not follow Edison's plans) for another flavor to be perfected.
+1 for Mike's position on Li-nnn individual cell monitoring. I think 48V systems should do individual battery monitoring as well, as I've seen the benefits in my 120VDC system.
If only more folks would unplug from the power companies, I think we'd see some new engineering and cost improvements in Ni-Fe for home power storage, where weight is irrelevant. It think the charge efficiency of NI-FE issue is a red herring for this application, since wet lead acid batteries are about 55% efficiency for the last 10% of charge, and we all try to keep our lead batteries topped off to improve longevity.
I may be biased in Edison's favor since my home is 120VDC powered, and my toaster and clothes iron are 1920's models which were designed to work with his DC power to the home.
I understand the need for the individual charge controllers. What's the issue with charge efficiency? They do seem to be a promising technology for off-grid. But I'd really like to see EEStore perfect their super capacitors. Oops, just checked the news on them, seems it's a scam.
The chemistry used in laptops, cellphones, (and probably) Dreamliners etc., are usually Lithium Cobalt types, which gives the best energy/weight ratio, but they are also the most thermal unstable. Using Manganese or Iron Phosphate adds some weight, but they're safer, and can often give higher continous amps, and longer life.
I had a ramble over at Otherpower about the Lithium-* tech over a year ago...: http://www.fieldlines.com/index.php/topic,146304.msg1000453.html#msg1000453 (http://www.fieldlines.com/index.php/topic,146304.msg1000453.html#msg1000453)
My only real experience with li-* batteries are with my E-bike with a 36V, 750W BLDC motor (avg. draw: 15-20A@36V). I started with 3pc. 12V, 18Ah SLA batteries, and i got max a 15km trip before the Low Voltage Disconnect kicked in. Needless to say, with a weight of 21kg and the short riding distance, they didn't last long on my bike... ;)
Then i got a 36V, 16Ah LiMn2Co4 with 4p10s 4Ah-cell config, and my mileage increased to 35km; weight: 5.5kg. This battery pack dwindled down to half capacity after 18 months.
My current battery are a 36V, 20Ah LiFePo4 with 2p12s 10Ah-cell config, with an 50km mileage; weight: 9kg. This battery pack are still going strong after 12 months, and there are no loss in cell capacity. (The cells Internal Resistance are still as new (8-12mOhm/cell).)
I use a 10A charger with a cell-balance port to charge the latest pack, since it has no internal BMS (Battery Managment System).
I'd love to swap out my current FLA bank (12V@1060Ah] with LiFePo4, but the price tag are still too high for me... :( (Edit: If one use only 30% capacity of a FLA bank, one can manage with a Li-* bank with 1/3 of the FLA capacity, since one can safely use 80% capacity of a Li-* bank...)
Edit;
I think the need for a good BMS would appeal to most off-grid users, because they really takes good care of each individual cell, and reduce the risk of abuse of the bank. :)
Tom- NIFE's have about 60% charge efficiency. Wet lead batteries charge efficiency declines dramatically with age, besides having lower charge efficiency for the last 10%, so their typical claimed 85% charge efficiency (from empty) is mostly fantasy for real home power use. There's no need for fancy battery management with NIFE. I like the NIFE technology, but not the current suppliers or prices.
Cornelius- I would love to get some AC magnetic field measurements from your motor. My epilepsy is set off my magnetic fields, and I wondered how much stray field there would be from this type of motor. I'd like to build an electric tricycle and wonder how far I'd have to extend the rear motor and wheel as my epilepsy is affected by AC magnetic fields. A hub motor is more convenient but a separate motor with sprocket drive would be easier to provide some shielding via mumetal or electrical steel. Don't suppose you have a magnetic field meter?
Bruce;
Sorry, no magnetic field meter... :(
The whole hub motor are encapsulated in aluminium,but i guess that doesn't shield the AC magnetic field much... The motor are from Goldenmotor (.com), and they also have motors with sprocket for trikes, up to 800W i think...
Bruce, I was asking about the charge efficiency of the Li-Fe batteries, which I understand is quite good.
Bruce,
What's an electric iron? ::)
Brett- My other vintage clothes iron is a late 1800's Mrs. Potts SAD iron. No electricity required. :)
Thanks Cornelius, alas the shaft drive BLDC motors I could find there are 5KW and up.
I have a SAD iron too......... it never gets used ;D
Quote from: Tom on February 04, 2013, 04:55:21 PMI was asking about the charge efficiency of the Li-Fe batteries, which I understand is quite good.
The first 50% of recharge (0-50% capacity) is pretty good, in the range of 90%. About the same as Pb-H2so4
But after you get to about 50% , it goes way down, somewhere less than 50%. And lots of distilled water "boiling" away. My battery shed sounds like a den of snakes after 11AM and the batteries start coming up on charge. All the cells bubbling away that nice distilled water. After having both Pb-H2so4 and now the NiFe bank, each has their advantages. NiFe consumes a lot of water, but can take a lot of abuse. And the Chinese cells are not made to Edison's original, refurbish-able specs, and can die anytime between year 10 - 20. And every 5 years, they will need an electrolyte change. That's going to be fun. Pb-H2so4 is "available" anywhere, but 10 yr seems to be the high side of a well treated battery......
Quote from: BruceM on February 04, 2013, 08:58:02 PM
Thanks Cornelius, alas the shaft drive BLDC motors I could find there are 5KW and up.
Click on 'BLDC Motor' in the menu on the left and scroll about 3/4 down the page, where you'll find the BLT series specially for trikes... :)
Hi Tom, thanks for explaining about the differing battery plates, I will be sure to consider this when purchasing, those PV1's you have sound fantastic,
BruceM, good day to you, point noted in charging forklift batterys, I could kick myself now, two years ago I gave in and sold a forklift battery pack, 48 Volt 800AH, and to make matters worse I saw no point in keeping the 48 volt single phase charger that came with the truck, I got this truck for pennies, and was offered good money, should have thought it through.
Ronmar, thanks for the 24 / 48 month info, did not know this, other than the above which was my own doing I have never had bettery problems, always check and dont abuse them.
Thanks again jonathan, I had been told many years ago that caring for batterys correctly was the key to long life and good financial return, by an old friend who has since passed on, its all coming back to me now, this man was a genius regarding generators, when everyone else was beat they eventually came to him, he lived in an old airfield hut, no grid power, used milk float batterys, anyway, I would like to thank you all for your help, its time for me to start looking for batterys, God bless, John