Battle Born Lithium

free radical wrote:
Will Prowse dyi solar chanel has great info

https://youtu.be/gOqQp2Xjr6U

Will Prowse is great and so is his solar forum !

12V LiFePO4 100Ah $555 Battery: Version 2! Easier to Assemble with Al Case Cells

That video is about 9 months old. People on his forum DIT Solar Power have stepped it up to the next level

Direct from China- 280AH x 8 (560 Ah @ 12V) for 1260.00 USD Delivered

pianotuna wrote:
I was under the impression that 1C was a "rule of thumb" with LI for current (amps). So a 300 amp-hour LI should laugh at a load of 130 amps continuous.

iirc the Battle Born can do 3C for five minutes.

It just depends on what the components are on the inside (or outside if it's a diy). That is why I said not all dropins are created equal. Some are constructed of many cylindrical cells, some pouches and others prismatic cells.

Not that I could charge or discharge my cells that are rated for 3c (battery bank 1,500a) an 10c pulse but limited to 400a by the 2 400a continous duty selenoids on the charge/ discharge.

The economics of it all are interesting. It would matter what the specs and costs are for that 250AH BB compared with their 100.

Say that Relion 300AH is limited to 100 amps and you need 130 amps. The cost is about $1,000 per 100AH.

To get the extra 30 amps you would need two of those 300 8Ds for another $3,000. $6,000 for 130 amps!

So if you went with 100AH batts that can do say 50 amps each and got three, you spent the $3,000 and get 150 amps.

If two 100s can't quite do the job you want so you need a third, will a 250 do it for less cost than three 100s? Can you get the extra 30 amps with an extra 50AH or do you need an extra 100 so the 250 won't do?

It can come out to anything, depending on the actual specs and costs, but does show, as was mentioned, that you really need to check those specs and costs to compare with your planned use.

BFL13,

A flooded 100 amp-hour battery does "best" at about 30 amps demand. It can do far more than that number. Look at the huge draw from a starter motor.

The SiO2 can do 9C for one second.

I truly doubt a 300 amp-hour LI is going to only allow 100 amps continuous.

Itinerant1 all other things being equal, the more cells the greater the continuous current capability. The trade off is the greater the number of cells the lower the mean time before failure. i.e. increased risk of failure over a given period of time.

FWIW, my 200a/hr drop-in was at 55% SOC this morning, so for test purposes I kicked on the 100a capable ProSine 2.0 charger (solar OFF) and the amps settled in at about 50a. In about 15 min time SOC is up to 68% - this is just a quickie, back of the envelope’ stat...Sure Li cost more, and it’s strictly up to the end user to determine the cost/value proposition - But as a former 16 yr 6v GC devotee myself (and a mostly desert dry camper), the rapid receptivity rate during solar harvest makes Li the hands down Best option ...as I write this SOC is now at 71%, charger amps running at 50.3a...

Another thing is that for capacity estimation purposes only, I can see no real need to subtract say 10% from the ‘top end’ because this IS truly usable, though I do accept the idea of 10% off the ‘low end’...

3 tons

Another factor is if you needed a little more capacity in the bank with Li it came out in an earlier thread you should not mix say a 200 with a 100 like you can with "ordinary" batteries.

So the 250AH size in one batt might be useful where if you did have a 200 already but needed another 50, you could not get a 100, but would have to get another 200. So be sure to do your your sums first and get the 250 instead of the 200.

You really need to know what your draws will be, which few people have any clue about estimating. I suppose asking about costs for Li is the same as other things---if you have to ask, you can't afford it!

Amp limit is determined by the BMS to protect the battery and internal connections.
The actual battery cells could melt down the whole package with no BMS.

Interesting read and good info, but a thousand dollar battery will never be in my rig. I do boondock, but my last Trojan T105's lasted 8 years and a few gallons of gas for my Onan keeps them up and happy. Enuf said.

"Enuf said".

Yes, it's understandable that for the average rv'er that only weekend camps or does little boondocking and rather be tied to a power pole or run a generator the cost can be overwhelming. But it is coming down especially if you diy and build the batteries from cells.

As a fulltime Itinerant that doesn't want to be a slave to a generator or rv parks with a lot of choices for boondocking. I took that rv park money that would of been paid out and put it into the system (batteries, inverter/ charger and solar) on the 5th wheel, which for "return on purchase" was 400 days of boondocking. Now with over 1,471 days boondocked out of 1,620 since install it has paid for itself and then some, plus a better rving experience out and away with nature. Quietly

If I can help or show what some of the benefits may be with LFP from my experience living off of them in an everyday use, great. But one still has to think "what if". Being out and away with a shutdown of power and not knowing what to do next can be a rude experience and an eye opener. Do your homework first.

Bottom line though use what best suits you for the conditions. There is no perfect way, just possibly more convenient. ;)

Itinerant1 has a magnificent system, one that any rv'er would be proud to own and use. All the "electrics" are from one company which ensures that they will "play well together".

For personal reasons, I would have gone Victron, or Outback instead of Magnum.

For technical reasons I would have moved to 48 volts for the battery storage.

There are 48 volt DC air conditioners.