anyone built any rv or home systems using these? It appears to be a very clicky network of posters on any forum that mentions it. Everything I have read turns into a pissing contest so I figured if any of the slightly friendlier seabreeze crew have ventured there. Seems it can be done at a decent price if your prepared to diy.
Select to expand quoteTurtleHunter said..
anyone built any rv or home systems using these? It appears to be a very clicky network of posters on any forum that mentions it. Everything I have read turns into a pissing contest so I figured if any of the slightly friendlier seabreeze crew have ventured there. Seems it can be done at a decent price if your prepared to diy.
I am waiting for a price to drop to reasonable levels. Tesla and otheres now manufacture battery at $150-200 per kW. What you pay now on EV is 3-5 time that and quality is very poor. I have few projects waiting beside my solar catamaran.I have nice electric ATV with died lithium battery 80v100Ah . I substituted for now with lead acid- which means that I have now 300 kg batteries - that doesn't help much on hilly bumpy terrain. In two years new lithium should come on market at reasonable prices and quality.
Next project is off the grid weekender home. I decided to stick with lead acid gel batteries for now. Same reason as above.
Turtle Hunting is a definite No No on the Queensland coast unless you are an indigenous "hunter and gatherer".
However the "indigenous hunter and gatherers" have had a sniff of the money they can get selling turtle and dugong meat.
Law says they can "hunt and gather" it and share amongst kin but no provision is made for selling.
The "Law" applies to everybody. End of.
Call that a thread hijack if you want Turtle Hunter but your handle suggests a lack of understanding.
Select to expand quote
I am waiting for a price to drop to reasonable levels.
What?? For turtle meat??
what are you on about cisco. Do you want to hear the story about my user name or have you got a comment regarding the subject lifpo4. For what it's worth the green turtles are the only ones you want to eat I hear.
Macro I figured you would pop your head up regarding this as it could of made your cat viable.
The tech isn't that expensive and actually works out cheaper over the long run but try and learn on the forums and everyone ends up fighting over the different methods of charging or balancing. It's usually between those that have done it cheap and those that want to sell all the bling. One side say's it's easy the other say's it needs all this bling to make these dangerous temperamental cells work. So far i havn't bought anything but am looking at spending less than a redarc lead acid system but going from 500 cycles to anywhere above 2000 (maybe up around 8000)
Select to expand quoteTurtleHunter said..
lead acid system but going from 500 cycles to anywhere above 2000 (maybe up around 8000)
That is the point. At this moment most of BMS are so bad that you hardly get 1 year of your expensive lithium battery pack. That is why I am waiting for big , good manufacturer coming into market. Something like PowerPack from Elon Musk
U need to declare your peak amp requirements.
Lifepo4 has REALLY bad sag, so in my applications I avoid them and build my own LiPos... just as stable if you keep them within their nominal range 3.6-3.9v/cell.
I use A123 cells and build all my packs but these are for light EV use rather than large scale. I agree price wise their use is suitable if you build your own and source reasonable cells that have been matched by someone who knows what they are doing. I bought my cells through Asia about 5 years agog all matched closely and they have performed extremely well.
I don't use a cell based BMS system as I have too many failures from them discharging cells below 2.2V and now use a separate RC charger that balances the cells precisely although slowly, but as my cells are matched closely this doesn't take much time.
My recommendations would be
1 Get cheap cells that have a proven performance from a reputable seller.
2 Make sure cells are matched as close as possible.
3 Design your cells scalable if you are combining smaller cells into larger packs, this will allow cells to be removed and changed if they fail.
4 BMS I have not good advice here good luck but make sure you can change the variables when charging or discharging rather than a dumb charger.
5 Don't fully charge your cells to 3.6v but bring them back to 3.55v as it will extend the life cycle a lot.
6 Don't discharge your cells below 80% with less equals better. I never go below 50% and I have not lost capacity at all in my packs.
7 Use quality fuses and good wire.
8 If you got the money get A123 20amp pouch cells they are the ducks nuts, these cells are on steroids, treat them nice I think you would get double or triple life from other cells.
I gained all my info from www.endlesssphere but that's more into light EV type projects but does have some info on larger storage projects.
Good luck with it and stay safe if you start to build your own battery system as I have had a one or two catastrophic shorts that have given me some bad burns.
Good article here TH www.pbase.com:443/mainecruising/lifepo4_on_boats&page=1
Maybe of help/interest also ? www.cruisersforum.com/forums/f14/lifepo4-batteries-discussion-thread-for-those-using-them-as-house-banks-65069.html
Thanks guy's good to see others are testing the water with new tech (although after reading all the forums it does almost seem old). I have been looking just at the prismatic cells as charge and load rates will be relatively small compared to what you guys use in EV so volt sag is no problem (hopefully).
Also I agree bms cell balancing seems pretty unreliable/inificient and hard on the cells as well as the fact it's not needed under low charge/load conditions while keeping away from the top and bottom of the charge cycle .
I am also amazed at the charging process that the leading brand companies are using for rv use. They seem set on making it as complicated as possible yet are still spending way too much time charging around 3.6v/cell for balancing every cycle???
I want to make a small bank for powering a portable fridge and learn a bit but are looking at only charging to 3.4v/cell with solar/dcdc and 240 so to keep the soc well bellow 100% to allow for some float charging time. i.e. solar gets to float by lunch and is still there to power loads.
I did read a heap of the cruisers forum too amonst others and I can't believe how off track and abusive it is. It makes seabreeze look pretty good. It would be like coming on here and all the shops slagging each other and never getting to the point of the post.
Select to expand quotecisco said..
Turtle Hunting is a definite No No on the Queensland coast unless you are an indigenous "hunter and gatherer".
However the "indigenous hunter and gatherers" have had a sniff of the money they can get selling turtle and dugong meat.
Law says they can "hunt and gather" it and share amongst kin but no provision is made for selling.
The "Law" applies to everybody. End of.
Call that a thread hijack if you want Turtle Hunter but your handle suggests a lack of understanding.
lifpo4 isn't the same as other lithium cells macro. They say they are almost impossible to blow up and if you keep your soc between 20 and 80% there is no need for expensive controllers that fail.
Thanks for the article firebob was interesting but slightly different scale to my beer fridge battery.
Fly surfer very low c rate just running a fridge but may be .3c charging (still very low relatively)
I will post some updates once I go from research to building and using.
Select to expand quotecisco said..
Turtle Hunting is a definite No No on the Queensland coast unless you are an indigenous "hunter and gatherer".
However the "indigenous hunter and gatherers" have had a sniff of the money they can get selling turtle and dugong meat.
Law says they can "hunt and gather" it and share amongst kin but no provision is made for selling.
The "Law" applies to everybody. End of.
Call that a thread hijack if you want Turtle Hunter but your handle suggests a lack of understanding.
Any opportunity
Select to expand quotehoop said..
Any opportunity
Like you. Following me around are you??
