LiFePO4 Batteries: Discussion Thread for Those Using Them as House Banks

[FlyingCloud1937]

Originally Posted by goboatingnow

The issue of brass to aluminium, to copper to stainless is common all through the electrical systems of typical boats. With Care and some compounds it causes no problems, even with poor care it causes " little" real problems.

" marinized Lifepo battery, ?" , few companies really make marinized anything ! ( including LA batteries )

Dave

Really

this boat came to me looking like this




Then I did this



then I did this



and this



where will your Li-Ion be in the next five years?

Lloyd

[T1 Terry]

Originally Posted by FlyingCloud1937

You decided..

Seems Terry is the only one tuning into what are real issue.

but answer me this?

15 years from today's date will you know what is wire aboard your marina neighbors boat?

Lloyd

Is the concern about possible battery fires due to an out of balance battery pack? Let me put your mind at ease, these cells do not burst into flame if over charged, they will vent a vapour similar to boiled petrol but adequate ventilation will disperse this before a major fire situation developed. Even dead shorted these cells won't burst into flame, I'll see if i can find the link to a few cell tests that shows just how tough these cells are.

T1 Terry

[FlyingCloud1937]

Originally Posted by T1 Terry

Is the concern about possible battery fires due to an out of balance battery pack? Let me put your mind at ease, these cells do not burst into flame if over charged, they will vent a vapour similar to boiled petrol but adequate ventilation will disperse this before a major fire situation developed. Even dead shorted these cells won't burst into flame, I'll see if i can find the link to a few cell tests that shows just how tough these cells are.

T1 Terry

No I'm not thinking that bats will burst into flames.

I'm thinking more about the boat bursting into flames.

One from the potential, and next from the lack of history...nothing vetted in the marine industry should be afraid.

My biggest issue is from people like Goboatingnow...

as the pics I just posted show, the original wring from factory install, through multiple owners.

until I corrected those sins.

While not directly battery related.

This whole caviler attitude, is the issue.

I am going to guess that I understand Li-Ion better then all, you might be the exception...but only to the nuance of hyper mileing the use without BMS.

I'm not sure that a real BMS isn't required.

Lloyd

Lloyd

[T1 Terry]

I found the You tube video, that is 2/0AWG cable that's smoking and around $250 per cell, what waste, but interesting all the same.

LiFePO4 test - borrowed - YouTube

As far as a BMS, every battery needs some sort of BMS, they would be over charged or completely flattened without some form of battery management. Active battery management on a 4 cells in series battery is waste of time and money and adds a real chance for a BMS board to fail and drag the cell flat. BMS systems that control the battery charger should be banned, set the charger for 3.45v per cell and use the BMS as a passive warning system and you won't have any problems. Expect a micro processor to be smarter than you are is asking for trouble. If you want a semi automated charging system, use the cell logger to turn the charger off when a cell hits 3.6v, you can check out why one cell went high at you leasure, even if the other cells only reached 955 charged, you still have a lot of stored energy to use before the next recharge is required.

T1 Terry

[Lagoon4us]

Lloyd has hijacked this thread with constant negative remarks, he has done it before to other good threads, frustrating good people to the point of not bothering sharing the knowledge, i think he needs to back off as he has no intention of any positive input.

The thread prior to his 'de-contributions' was a good one/best one, informative and fresh, there are 6 or so very VERY knowledgeable people here that are being treated as fool's by his incessant one track jibe's.

Had enough of his rot....rant over, Ciao Lloyd it needs to be said, you are a tosser!

[FlyingCloud1937]

Originally Posted by Lagoon4us

Lloyd has hijacked this thread with constant negative remarks, he has done it before to other good threads, frustrating good people to the point of not bothering sharing the knowledge, i think he needs to back off as he has no intention of any positive input.

The thread prior to his 'de-contributions' was a good one/best one, informative and fresh, there are 6 or so very VERY knowledgeable people here that are being treated as fool's by his incessant one track jibe's.

Had enough of his rot....rant over, Ciao Lloyd it needs to be said, you are a tosser!

dear lagoon,

really,

I thought this thread was about using Li-ion on boats.

It seems Terry-1 the original Li-Ion guy here understands my point. Sorry you don't.

I think even Main...ail understands my point.

If I'm not cheering to your satisfaction does that make me wrong and you right.

Lloyd

[hellosailor]

"Which clearly appears to have a copper neg. post with what appears to an alum..nut"
What makes you think ALUMINUM for anything? Those nuts look like generic standard zinc galvanized steel to me.

How do you figure those hoofbeats mean zebras?

[goboatingnow]

No I'm not thinking that bats will burst into flames.

I'm thinking more about the boat bursting into flames.

One from the potential, and next from the lack of history...nothing vetted in the marine industry should be afraid.

You are degenerating into a troll here, people are taking T1Terry out of context, he actually has to keep correcting people that are applying what he said incorrectly.

The fact is , whatever you think of me, Li is a safe stable technology, especially LI Ferrous. It can take more abuse then LA, its easier to charge then LA and it has characteristics that really shine in Boat applications , unlike say AGMS

The boat is far far morel ikely to burst into flames for lots of reasons that have nothing to do with Li, just making off teh cuff remarks like that adds nothing to the rational debate.

I fully agree with LAgoon, this was a purely technical thread looking at the processes and procedure to apply such cells, it has been ruined by troll like comments

If you ( or any one else ) has specific data relevant to the use of these cells then BY ALL MEANS , contribute, else stop spouting unsupported hearsay, or misrepresenting situations, or talking about irrelevant issues, like insurance. Its clear you will not be going near Li. Leave the rest of us to get on with that bit.

Thanks

Dave

[dansken]

Dear Lloyd,
You have now made your point and everybody following this tread and the other associated treads understand that LiFePo4 is beyond your level of comfort. And, that you otherwise haven’t got anything constructive to contribute.
Please stop posting here

[senormechanico]

Originally Posted by catakate

If one is idiotic enough to measure cell's voltage over a 30' cable, that's his problem. From reading this thread I understand all those testing these products are aware of that, so what is your point?

At the risk of further thread drift, let's just say that "30' cable" is .050 standard ribbon cable.
The total length of the loop from the batteries to the meter and back is therefore 60'.
Resistance of the aforementioned cable is 6.49 ohms per 100'.

Resistance of Wire (Wire Resistance Calculator)

Therefore 6.49x0.6=1.08166 ohms.

The standard digital meters in use today have an input impedance of 11 meghohms, or 11,000,000 ohms.
Therefore, the voltage drop across the ribbon cable is about as close to near zero volts as you can get.

BTW, I am a retired electronics servicer.
Your move.

[deckofficer]

As I wiped a tear from my eye upon seeing the destruction of those cells I have to wonder if the guy has the coin to toss like that, why wasn't the camera recording the test of better definition? Even the lowly GoPro (which I have one) would have been a vast improvement.

Thanks for sharing T1 Terry.

[NahanniV]

Originally Posted by hellosailor

"Which clearly appears to have a copper neg. post with what appears to an alum..nut"
What makes you think ALUMINUM for anything? Those nuts look like generic standard zinc galvanized steel to me.

How do you figure those hoofbeats mean zebras?

The nuts are non magnetic and quite soft (easily scratched), almost certainly aluminum.

Originally Posted by senormechanico

"......
Therefore 6.49x0.6=1.08166 ohms.
......

6.49x0.6=3.894 on my calculator, but 3.894 times almost zero current is still "about as close to near zero volts as you can get".

I plan to monitor my cells remotely (<10'), might use twisted pairs if noise becomes a problem.

I have my 4x400AHA cells in parallel charging now, but the best I can manage with my power supply is about 6A (with external fan).

I'm starting to think about switching them to series and charging with a 40A 12V charger, then topping up any individual cells that need it.

Cheers,
JM

[ColdEH]

You would think that someone would make gold plated connectors .

Or even send them out for plating, anyone have any thoughts ?

Regards

[T1 Terry]

I have a 40 amp 12v switch mode charge I bought from evilbay that will charge 1 cell if I want. I'm not saying these chargers are suitable for use on a boat, it's a much tougher environment there, but the principle may be the same.
After 2yrs and a lot of feed back from other systems I had a hand in one way or the other, the easiest was to balance a pack appears to be topping up the lower cells rather than draining the high ones. If you find one cell repeatedly reaching 3.6v well before the others, top up the lowest cell, but do it at the 3.6v end, not at the bottom of the charge or part way through, the cells end up a long way out of balance if you attempt to do that.
As many have mentioned, the length of the cable feeding a meter only will have no effect on the reading, but a bad joint will. If you find a cell reading a long way different to the others, double check at the battery itself before you start attempting to balance the cells, you may be trying to fix something that isn't a problem and in fact create one instead.
I like using the Junsi cell loggers from the hobby suppliers, cheap and reliable, use 2 plugs that require purchasing separately, install one with a long cable so the logger lives with you other monitoring gear, the other plug leave at the battery, it makes it quick and easy to do the balancing that way and will very quickly point out a wiring problem as apposed to a cell balance problem.
I like to use trailer wiring harness cable for the extension, way overkill as far as size but it won't fail due to conductor fracturing when the going gets rough, it's already a twisted set and it's quick and easy to fit and identify at each end.
Don't be tempted to use any of the logger wires as a power supply no matter how small the load maybe, it will cause you never ending headaches with fluctuating readings that just don't make sense.

T1 Terry

[mcarling]

We have decades of data showing that lead acid batteries are unsafe and unsuitable for use on boats. If Lloyd wants to keep using them because we have only years of data showing that LiFePO4 batteries are safe and suitable for boats, that's his business, but I don't want be next to him in a marina.