Lipo vs lifepo4

[hellosailor]

Some of those aircraft were lost due to batteries being carried as cargo. Which has the FAA and TSA and everyone else quite unhappy about whether they should ban laptops and cell phones and everything else from the cargo hold. Or maybe the cabin. Or maybe set a size (watt-hours) limit on battery powered equipment. Or...All anyone can agree on, is that they can't understand all the subtleties yet. In the R/C hobby communities, apparently fire-resistant battery cases are becoming common, as they're also getting tired of things going up in flames at random times.

And the acrid stench of a lithium battery fire makes them quite impractical for toasting smores.

[john61ct]

As long as everyone realizes all this talk of fire danger applies to LiPo and NMC

Not to LiFePO4/LFP, at least no more than lead when properly installed and maintained.

[hellosailor]

US car owners get taken to hospitals something like 10,000 times per year, often with eye damage from exploding lead acid batteries while incorrectly jumping cars. (That's one reason car chargers these days often will simply refuse to even power-up on a truly dead battery.)

So yes...we forget there are some problems wit conventional batteries as well.

But I think "every" lithium chemistry is finickier than lead, and with the greater energy storage capacity, comes with greater fire starting abilities, and the potential for a better show.

Heck, if I find a nice rectangular cast iron Dutch oven in a thrift store...I know where my cell phone and tablet are going to start spending the nights. As the innkeeper(?) said to Inspector Clouseau, "Yes, but thet's not *mah* dog."

[newhaul]

Originally Posted by hellosailor

US car owners get taken to hospitals something like 10,000 times per year, often with eye damage from exploding lead acid batteries while incorrectly jumping cars. (That's one reason car chargers these days often will simply refuse to even power-up on a truly dead battery.)

So yes...we forget there are some problems wit conventional batteries as well.

But I think "every" lithium chemistry is finickier than lead, and with the greater energy storage capacity, comes with greater fire starting abilities, and the potential for a better show.

Heck, if I find a nice rectangular cast iron Dutch oven in a thrift store...I know where my cell phone and tablet are going to start spending the nights. As the innkeeper(?) said to Inspector Clouseau, "Yes, but thet's not *mah* dog."

I had one explode on me just unhooking the charger . It was on the work bench in my old shop. ( and yes the charger was unplugged ) .deep cycle Fla

[john61ct]

Sorry but calling out fearmongering.

Yes sh1t happens.

But reducing your ignorance, learning how to care for your electric system properly will reduce any risks (lead or LFP) to **way** below those you take on every day e.g. driving on public roads, eating animal products or taking a shower.

Any battery or bank should be retired when capacity has declined by 20-30%.

Yes most people keep using them until their outward symptoms make it clear they passed that point years ago.

So if you really want to be safe, start doing regular 20-hour load tests! Should be doing that anyway, best feedback if you're taking good care.

Too much trouble?

Then don't talk about the danger anymore.

[Maine Sail]

Originally Posted by newhaul

Just got a message from the supplier and these $1.50 an ah batteries are what I am going to get . Turns out they are lifepo4 not Lipo now do I get 4 of the 100ah. Or 2 of the 160ah batteries. Replacing 440 ah of Fla gc2's. I estimate my daily to be about 50ah a day once I install the refer.

We can't help you if you don't supply a link to the product. EditI did find the 100Ah claimed model..

13.6" X 10.3" X 2.4" and 11 pounds including a case and internal BMS...... Not so much.... They are simply selling bovine dung and can only be lying about Ah capacity.

A single 3.2V CALB 100Ah cell weights 7.24 pounds or 28.96 pounds for a four cell 12V nominal pack. 29 pounds is just the bare cells no jumpers, bolts, BMS or case and this is a legitimate 100Ah LiFePO4 cell.....

There is a boat load of snake oil Li stuff foisted upon uneducated buyers via places like AliExpress. Unless you know who the actual manufacturer is, and they all "claim" to be, but are not, and you have taken the time to fully educate yourself then venturing into house bank territory via Aliewhatever is most likely to get you scammed out of your hard earned money.

I have purchased a lot of cells from AlieExpress for destructive testing. One thing I have learned is that the cells and batteries sold there are either rejects or counterfeit. Not a single cell I have purchased from AlieXXX has delivered its rating. Even when I buy "matched cells" they can vary in capacity by as much as 20%.. Remember all the rejects from somewhere have to go somewhere else and that seems to be eBay, AlieExpress etc....

Originally Posted by newhaul

Why disable the temp compensating on the solar?

I mean no disrespect in saying this but if you have to ask why you don't use LA temp compensation with LFP, you are simply not yet ready to be investing in LFP . Please keep reading and researching....

[newhaul]

Originally Posted by Maine Sail

We can't help you if you don't supply a link to the product.

There is a boat load of snake oil Li stuff foisted upon uneducated buyers via places like AliExpress. Unless you know who the actual manufacturer is, and they all "claim" to be, but are not, and you have taken the time to fully educate yourself then venturing into house bank territory via Aliewhatever is most likely to get you scammed out of your hard earned money.

I have purchased a lot of cells from AlieExpress for destructive testing. One thing I have learned is that the cells and batteries sold there are either rejects or counterfeit. Not a single cell I have purchased from AlieXXX has delivered its rating. Even when I buy "matched cells" they can vary in capacity by as much as 20%.. Remember all the rejects from somewhere have to go somewhere else and that seems to be eBay, AlieExpress etc....




I mean no disrespect in saying this but if you have to ask why you don't use LA temp compensation with LFP, you are simply not yet ready to be investing in LFP . Please keep reading and researching....

but how does one learn if they don't ask questions? Also the temp compensation I actually have never seen it written to be specific to LA batteries. So I asked the question.

Also as cheap as they are I don't expect them to be top shelf . If they perform adequately on the bench then they go into the boat and I will post the results.

[Maine Sail]

Originally Posted by newhaul

but how does one learn if they don't ask questions? Also the temp compensation I actually have never seen it written to be specific to LA batteries. So I asked the question.

Also as cheap as they are I don't expect them to be top shelf . If they perform adequately on the bench then they go into the boat and I will post the results.

You're not getting a 100Ah LiFePo4 battery, no matter how good they work. They simply can't beat physics, unless they lie.. By physics I mean there is no way to fit 100Ah (ampere hours) of LFP into that weight & size box at 12V nominal.

In other words if I slap a pork label on a goat, and sell it to you as pork, do you have pork or goat meat....?

[newhaul]

Originally Posted by Maine Sail

You're not getting a 100Ah LiFePo4 battery, no matter how good they work. They simply can't beat physics, unless they lie.. By physics I mean there is no way to fit 100Ah (ampere hours) of LFP into that weight & size box at 12V nominal.

In other words if I slap a pork label on a goat, and sell it to you as pork, do you have pork or goat meat....?

I fully realise that I am getting at best 50ah and at worst I'm losing a couple hours worth of my labor. On this project but as I said its for testing and worst case I will have one heck of a backup battery for my tablet.
( as to the other question doesn't matter pork or mutton you are getting grease in a can.) I'm Scottish so either is fine . Keeps things moving along.)

[john61ct]

Originally Posted by newhaul

Also as cheap as they are I don't expect them to be top shelf.

Like saying "it's OK if they're second-rate strawberries" when you're actually getting currants.

How will you know how to charge them? You won't even know what chemistry they are?

Here's where you **do** get into fire risk territory.

[newhaul]

Originally Posted by john61ct

Like saying "it's OK if they're second-rate strawberries" when you're actually getting currants.

How will you know how to charge them? You won't even know what chemistry they are?

Here's where you **do** get into fire risk territory.

By taking a look under the hood how else. I won't have any issues testing will not be on the boat and will be conducted in my welding booth. Basically fire proof with exhaust system.
Thank you everyone for the words of caution. I had intended to fully vet the battery before putting myself at risk.

[newhaul]

Here is a screenshot of the specs for the battery I am going to order if it doesn't cost more to ship than to buy it. Still waiting to hear the shipping costs.

[john61ct]

So that's a different one, 6.8 lbs to get how many AH?

Sure if it's a cheap science project and you know how to keep safe, go for it.

But me, soon as I see any sign of dishonesty from a vendor - especially batteries or solar, and hate to say it, but **most** especially mainland Chinese selling direct online - I keep looking elsewhere, don't waste my time looking at them any further.

[newhaul]

Those specs were actually for the 80 ah ( claimed by them ) unit .
I actually expect just under half the ah they rate it at.
Besides its winter need something to occupy myself with.

[newhaul]

Also those were the specs I was able to dig up from outside source and not the seller.