Cheap LiPo 12v batteries

[Itinerant1]

It should see it and disconnect it "if" it has a hvd, but will it be in time to stop a thermal run away?

On the prismatic cells it "should" pop the saftey valve and vent.

On the drop ins with many cylindrical cells what will happen?

[jcussen]

Have not heard of any battery fires on the new Tesla 3, [165000 sold] so maybe Tesla found out a way.

[Smitty77]

So assuming that $4k cost included the batteries and the transportation to you door - thats ~$285 per 100AH. With a range of 2000-5000 life cycles, assuming you (or someone) were to stay at the 40-50% SOC range, conservative to hope to see 3500 cycles out a bank. (Probably much more, but other things then AH's In/Out impact Life Cycles.) At 3500 cycles, that would hair over $.08 (.082, rounding to 3 decimals) per cycle per 100 AH.

Lifeline L16's 6V X's2 to get to 12V and 400AG are about $1350. Which is about $337 per 100 AH.

Lifeline 8D's 12V 255 AH are about $699. Which is about $274 per 100 AH.

I won't do the math on the per Life Cycle, but 1000 Life Cycles at a 50% SOC, or just a little short of 2000 Life Cycles at a 70% SOC.

And yeah, the regular comments about less weight, faster charging, steady discharge rates, etc., etc.

You can see why as the process come down on lithium batteries, the pendulum will most likely continue to them becoming the RV'ing favorites over the years ahead...

And my post purpose? Just thinking out loud, and enjoying the ongoing info sharing on this forum!

Best to all,
Smitty

[jcussen]

Originally Posted by Smitty77

So assuming that $4k cost included the batteries and the transportation to you door - thats ~$285 per 100AH. With a range of 2000-5000 life cycles, assuming you (or someone) were to stay at the 40-50% SOC range, conservative to hope to see 3500 cycles out a bank. (Probably much more, but other things then AH's In/Out impact Life Cycles.) At 3500 cycles, that would hair over $.08 (.082, rounding to 3 decimals) per cycle per 100 AH.

Lifeline L16's 6V X's2 to get to 12V and 400AG are about $1350. Which is about $337 per 100 AH.

Lifeline 8D's 12V 255 AH are about $699. Which is about $274 per 100 AH.

I won't do the math on the per Life Cycle, but 1000 Life Cycles at a 50% SOC, or just a little short of 2000 Life Cycles at a 70% SOC.

And yeah, the regular comments about less weight, faster charging, steady discharge rates, etc., etc.

You can see why as the process come down on lithium batteries, the pendulum will most likely continue to them becoming the RV'ing favorites over the years ahead...

And my post purpose? Just thinking out loud, and enjoying the ongoing info sharing on this forum!

Best to all,
Smitty

Your math is right, and considering big rv manufacturers can buy in bulk and get a much better price than you or I, lithiums will probably be standard on higher end coaches in the next 10 years or so. Almost a necessity when you consider how many coaches come stock with electric only fridges.

[radar]

Originally Posted by jcussen

Have not heard of any battery fires on the new Tesla 3, [165000 sold] so maybe Tesla found out a way.

I believe they are well over 300,000 sold now. Essentially about a thousand per day. That’s not including model S or Model x.

[Finance]

Originally Posted by 10 fan

All 7 in parallel, 12v I made buss bars, no fuses for each battery. 400a fuse for each inverter, 150a fuse for house 12v and I put the original 350a inverter fuse on the cable going to the bi directional relay because there was no protection.

Personally I’d install a terminal mount fuse at each battery. All batteries fail eventually. If one fails open circuit in parallel no sweat. If it fails with a shorted cell then six batteries will discharge into 1.

[jcussen]

Originally Posted by radar

I believe they are well over 300,000 sold now. Essentially about a thousand per day. That’s not including model S or Model x.

Have you read any reports of battery caused fires on the 3?

[radar]

Originally Posted by jcussen

Have you read any reports of battery caused fires on the 3?

Not one on the model 3.

There have been 44 on the model S but I don’t think any since the software update.

They actually track it and make it public now. EV’s are considerably less like to experience a fire than a liquid fueled car. And if on autopilot considerably less likely to be in an accident.

http://https://teslamotorsclub.com/blog/2019/07/18/tesla-releases-q2-safety-report-adds-vehicle-fire-stats/

[glasman98001]

Hi everyone,,,,well i found some of these lithium batteries the o.p posted about,,,,wondering if u would have to put a battery moniter on each battery if they are run parallel ? they are 45amp ea so i would run 4 of them parallel. Any other words of advisement before i go down this road ? Oh yea,,,, there is more of them left if anyone interested ...in washington state...

[10 fan]

Originally Posted by Finance

Personally I’d install a terminal mount fuse at each battery. All batteries fail eventually. If one fails open circuit in parallel no sweat. If it fails with a shorted cell then six batteries will discharge into 1.

I have not seen or heard of anyone doing this as a necessary step. Will give some thought to this in the future, Thanks.

[twinboat]

This is what's used in large battery banks in the marine industry.

Fits right on the battery + terminal and you pick what size fuse up to 300 amps.

[10 fan]

Originally Posted by twinboat

This is what's used in large battery banks in the marine industry.

Fits right on the battery + terminal and you pick what size fuse up to 300 amps.Attachment 254165

Thanks, that looks like an easy change with my buss bar set up. When I get home there are 6 more panels waiting for the second string and I just installed the new BIM so the alternator can help. I want to try one AC off of each inverter at the same time. If that works I can decide on the fuse size.

[trackvw]

there were some of the green ones like the first photo at my local electronic swap meet is morning ,

$100 each if you happen to be around Orange County , CA to pick them up......