I was quite pleased to find that the solar street light I opened recently had a LiFePO4 (Lithium Iron Phosphate) cell in it. They are really well suited to that application due to their long term stability and superior number of charge/discharge cycles. The downside is that they are much bigger for a similar capacity. But that's not an issue in an application like this. Especially given the size of the battery compartment in the light.
Here's a link to Rich Rebuilds little incident. It's spectacular and also educational.
https://www.youtube.com/watch?v=WdDi1haA71Q
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
http://www.bigclive.com/coffee.htm
This also keeps the channel independent of YouTube's advertising algorithms allowing it to be a bit more dangerous and naughty.
Here's a link to Rich Rebuilds little incident. It's spectacular and also educational.
https://www.youtube.com/watch?v=WdDi1haA71Q
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
http://www.bigclive.com/coffee.htm
This also keeps the channel independent of YouTube's advertising algorithms allowing it to be a bit more dangerous and naughty.
Since you mentioned practicality of solar Christmas lights.. Yay Clive!! I have played with a standard sized garden "solar bank", panel about 95mmX80mm with lithium Ion, as well as many 50×50 with NiMh. The NiMh units all had 600 or 800mAh and "high" operating current of 35 to 50mA and drained the cell whether or not connected to a string of lights. My load was the magnet wired seed/fairy lights that required only about 15mA but unfortunately could not span even one cloudy summer day. One unit that is NLA had 2mA operating I. I imagine that's either about protection from overcharge or poor design. The lithium bank had 8mA drain, auto-dimming, a cheapo 1200mAh cell, and performed well even during the winter solstice near Toronto, Canada. Not super bright, but indeed super pretty. Partially thanks to you I have custom 12/24" pitch fairy lights… Beware of the wasteoids!!
I would love to buy some dedicated LiFePO4 protection boards but the usual sites lump them into the 18650 boards. I think I found some.
Another point of having two MOSFETs, even if there wasn't the diode issue, is that it allows it to independently block charging vs discharging. When the battery is at its max voltage, you want to be able to prevent further charging, but you don't want to prevent discharging (which would just make the battery useless), and likewise when it's too low, you want to prevent further discharging but don't want to prevent somebody being able to charge it back up to make it useful again…
I started buying only LiFePo, because in Arizona and West Texas, the denser/standard lithium battery packs for jump starting a car or charging a phone will expand. Never had one explode, but it's not worth the risk. I even used a permanent car battery size for a few years, and it had no trouble in freezing 🥶 or burning 🥵 temps.
Big Clive I found 1 problem with your video tesla battery's are li-ion not lifep04 so richs fire was li-ion not lifep04
Lifep04 are not as dangerous as you are thinking 🤔 😉 😏 😄 p.s. I love both of your channels ave is a great channel too check it out people
Great video , thanks, it will be interesting to see how this technology develops. It seems to have a lot of potential.
Hey BigClive, Pro Tip that I use at my Aerospace job; Score the heatshrink and then hit it with a heat gun and let it split itself.. 😛
Lithium Ion Vs Lithium Iron.
What a wonderful language we use.
Check out Jack Ricards you tube videos on his EVTV channel. He goes into great detail on the safety of LIFEPO4 calls compared to other chemistries and advocates their use in electric vehicles. The only production EV using LIFEPO4 cells is the Tesla Model 3 standard range and only starting very recently. My 2019 model 3 uses the Tesla 2170 cells which are not LIFEPO4.
The Tesla cells are not LIFEPO4 cells. They are much higher energy cells.
question is, can i do a direct swop say on an LED lantern or and USB FAN. Where it's connected to an 3.7v 18650 2500mah or 3000mah. then connect it to a 32650 with bms 5000mah? (excluding the physical size of 32650 is obviously bigger battery.. but charging and lifecycle and safety wize) can one do a direct swop. to get more capacity and longer lifetime for fan or LED lantern?. They both normally charge the internal battery from a 5V source via USB cable (micro usb or usb-c)
How is life cycle determined in lifepo4 batteries?….Thanks
any thoughts on using say a 36v 16a lifepo4 battery in my e bike. i see them for about £200 on ebay, has anyone got any experience? my last battery 36v 10a normal li ion battery only lasted about 2 years , would like something that lasted longer if possible
Life – po 4
Excellent video. I like to tinker with things myself and learning about batteries has helped me. I have two solar street lights. Two things I look for is:
1. How much does the solar panel actually output
2. What type of batteries are in it and are they actually rated for the capacity spec
Well I found that the panel indeed outputs what the specs stated on the listing.
But with the batteries this is where they go cheap to save money. Usually some used grade b cells that are 40-70% rated capacity. Which is why most people find that the solar light stays on for half or less than what stated. Most cases there is more room in the casing to upgrade the battery capacity.