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11-20-2019, 02:17 PM
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#1
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Bus Crazy
Join Date: Apr 2019
Location: SW USA
Posts: 2,064
Year: 2003
Coachwork: IC / Amtran
Chassis: CE300
Engine: International T444e
Rated Cap: 23
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Battleborn LiFePo4 batteries & paralleling
Aside from the basics, I know very little of LPF in regards to BMS &/or wiring configurations. For many reasons, not the least of which being the hot-ass battery-killing climate we live in, I'm now pulling a 180 on my planned AGMs & strongly reconsidering LiFePo4 batteries.
Battleborn - made in the USA w/ a 10-year warranty - are tops on my list. Unfortunately, the only 24V batteries they make are 50AH, so I need 4 (minimum) for 200AH.
If I was paralleling 4 LA batteries I - well - I wouldn't be paralleling 4 LA batteries period. But the Battleborn folk say their internal BMS makes it A-OK. Is this true?
If I go this route, I plan on fusing each leg. Anything else I should be doing? Are there other options @ the same ~ price point ($4k for 200AH @ 24V) that you'd recommend over these?
For what it's worth, I checked out Bioenno, which I've used for other stuff, but the biggest 24V they make is 100AH, and they recommend to avoid paralleling.
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11-20-2019, 02:22 PM
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#2
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Bus Geek
Join Date: May 2016
Location: Eastern WA
Posts: 6,402
Year: 2002
Coachwork: Bluebird
Chassis: All American RE (A3RE)
Engine: Cummins ISC (8.3)
Rated Cap: 72
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Have you considered 6 volt or 12 volt batteries in series?
I am using 4 L-16 batteries in series. That yields a 24 volt 400 amp hour bank.
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11-20-2019, 02:31 PM
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#3
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Bus Geek
Join Date: Nov 2016
Posts: 2,775
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Assuming you are set on LFP rather than lead
Drop-ins are really not the way to go.
Either go all the way to packaged systems like Victron or Lithionics, or DIY the learning curve with bare cells.
I would not parallel more than a couple strings, 3 at most. BB's internal BMS will do nothing wrt the meta-balancing issues.
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11-20-2019, 02:32 PM
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#4
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Bus Nut
Join Date: Aug 2018
Location: Santa Rosa, CA
Posts: 251
Year: 2007
Coachwork: ICCORP
Chassis: CE300
Engine: DT466
Rated Cap: 16
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I use two Renogy LiFePo4’s 170ah @ 12v in parallel for 340ah @ 12v. You can certainly do a parallel/serial config to get 340ah @ 24v. It would be pricey but it’s certainly doable.
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11-20-2019, 02:45 PM
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#5
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Bus Crazy
Join Date: Apr 2019
Location: SW USA
Posts: 2,064
Year: 2003
Coachwork: IC / Amtran
Chassis: CE300
Engine: International T444e
Rated Cap: 23
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Quote:
Originally Posted by PNW_Steve
Have you considered 6 volt or 12 volt batteries in series?
I am using 4 L-16 batteries in series. That yields a 24 volt 400 amp hour bank.
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That is EXACTLY the same bank I had planned before I started worrying about heat killing my $2700 investment. A line of thought I started going down thanks to your comments in the 'battery tender' thread, Steve
Obviously, there are other advantages - weight & size - but the main reason I'm now toying with the idea of LFP is our heat.
If I'm off base, let me know! I'd love to stick with my original plan which cost way less up-front dinero!
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Our Build: Mr. Beefy
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11-20-2019, 02:57 PM
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#6
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Bus Crazy
Join Date: Apr 2019
Location: SW USA
Posts: 2,064
Year: 2003
Coachwork: IC / Amtran
Chassis: CE300
Engine: International T444e
Rated Cap: 23
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Quote:
Originally Posted by john61ct
Assuming you are set on LFP rather than lead
Drop-ins are really not the way to go.
Either go all the way to packaged systems like Victron or Lithionics, or DIY learning curve with bare cells.
I would not parallel more than a couple strings, 3 at most. BB's internal BMS will do nothing wrt the meta-balancing issues.
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That's pretty much what I was concerned about. And no, I'm not really wanting to spend the time to become a proficient battery-builder. I've already got more new-to-me skills to count on my must-learn list.
Yeah, both of those are outside my price range. Relion makes one that's a little bit better regarding cost. Is that a reputable manufacturer?
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Go away. 'Baitin.
Our Build: Mr. Beefy
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11-20-2019, 03:01 PM
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#7
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Bus Geek
Join Date: Nov 2016
Posts: 2,775
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No idea.
Stick with quality deep cycling lead then, IMO
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11-20-2019, 03:50 PM
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#8
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Bus Geek
Join Date: Dec 2015
Location: pa
Posts: 2,527
Year: 98
Coachwork: 1. Corbeil & 2. Thomas
Chassis: 1 ford 1998 e350 4x4 7.3 2 mercedes 2004
Engine: 7.3 powerstroke & MBE906
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We converted our old electric cars from lead to lion. For one we used a Nissan leaf pack ..$3400 included shipping...the other Chevy volt pack with cosmetic damage from a local junkyard...$900...
We ran 1/2 the Nissan leaf pack in parallel to the other half.. No cooling or BMS.. After two years...daily charge... the cells drifted 50 mvolt.
Cells out of automotive applications are very well matched..
Temp and cooling is not a problem unless you have prolonged large charge or discharge currents. Not something you have in a house battery. 200 amp per cell is not a problem.. If you parallel 4 sets if a Nissan leaf ..Like others have done... Then you will have no issues.. Just stop at 4.0 volt and not lower then 3.4 volt..
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11-20-2019, 03:57 PM
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#9
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Bus Geek
Join Date: Nov 2016
Posts: 2,775
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IMO the LI chemistries used in EVs pose too much fire risk for use in mobile living spaces once removed from their protective systems.
LFP is the only mainstream one safe enough.
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11-20-2019, 04:28 PM
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#10
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Bus Nut
Join Date: Dec 2017
Location: Southern Maryland
Posts: 505
Year: 1986
Coachwork: Gillig
Chassis: Phantom
Engine: CAT 3208
Rated Cap: 87, says Gillig...
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Quote:
Originally Posted by john61ct
IMO the LI chemistries used in EVs pose too much fire risk for use in mobile living spaces once removed from their protective systems.
LFP is the only mainstream one safe enough.
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You say "IMO" but then you state "LFP is the only mainstream one safe enough" is if it is a fact. Please stop...
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11-20-2019, 04:30 PM
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#11
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Bus Geek
Join Date: Dec 2015
Location: pa
Posts: 2,527
Year: 98
Coachwork: 1. Corbeil & 2. Thomas
Chassis: 1 ford 1998 e350 4x4 7.3 2 mercedes 2004
Engine: 7.3 powerstroke & MBE906
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I hear you on that but then I had one of the two car battery in our econoline explode..... I had a top and acid come out of an exploding forklift cell..... Hydrogen... Sofar no problems with the lithium...
I will take my chances
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11-20-2019, 06:50 PM
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#12
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Bus Geek
Join Date: Nov 2016
Posts: 2,775
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Yes lead batteries can explode too.
Still stand by my statement, if you want to so science experiments with LI chemistries other than LFP keep it in the back shed.
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11-20-2019, 07:12 PM
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#13
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Bus Nut
Join Date: Dec 2017
Location: Southern Maryland
Posts: 505
Year: 1986
Coachwork: Gillig
Chassis: Phantom
Engine: CAT 3208
Rated Cap: 87, says Gillig...
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Quote:
Originally Posted by john61ct
Yes lead batteries can explode too.
Still stand by my statement, if you want to so science experiments with LI chemistries other than LFP keep it in the back shed.
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And again, opinion as fact; please stop, and go help D&D build his PV system.
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11-20-2019, 07:45 PM
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#14
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Bus Nut
Join Date: Aug 2018
Location: Santa Rosa, CA
Posts: 251
Year: 2007
Coachwork: ICCORP
Chassis: CE300
Engine: DT466
Rated Cap: 16
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There’s a HUGE difference in the chemistries between Lithium ION and LiFePo4. The former is what you hear about catching fire. The later is much more stable and what is used in these types of applications.
Please be sure your knowledge is applicable to the situation before offering it - especially with opinions.
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11-21-2019, 11:26 AM
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#15
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Bus Nut
Join Date: Apr 2018
Posts: 421
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Read this carefully:
https://lithium-car-battery.3dcartst...%20Strings.pdf
I have 32 3.2V 30amp Lifepo4 pouches that I'm wiring in series and parallel to get 24v and 120amps. This would be annotated as 8S4P, or 8 in series and 4 in parallel.
Mine are different than yours as I have the aluminum tab instead of bolts on each cell, but the idea is still the same. Look at the first two diagrams carefully, and figure out what your configuration is. It sounds like yours is going to be a 4S1P (meaning you only have 4 cells in series), so you can wire yours up like the first diagram.
I'm not sure how the internal BMS works... but for an external one check out the wiring diagram here: https://www.electriccarpartscompany....agement-System
In fact, you should explore that site to get some different options ( https://www.electriccarpartscompany.com/) sometimes the shipping can be painfully long, but you can't beat the prices and quality. Warning: Carl is a one man shop there, and demand is high, so your best bet is to call your order in. I already had my batteries, and I have an AIMS 24v inverter charger and MPPT controller, so all I got from them was the BMS and 8 balancers.
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11-21-2019, 11:53 AM
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#16
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Bus Geek
Join Date: Nov 2016
Posts: 2,775
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Quote:
Originally Posted by Pizote
There’s a HUGE difference in the chemistries between Lithium ION and LiFePo4. The former is what you hear about catching fire. The later is much more stable and what is used in these types of applications.
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Yes that is exactly what I'm saying.
LFP is just one of many dozens of LI chemistries.
It and LTO just happen to be exceptionally safe, compared to those used in EVs in recent decades.
LCO NMC NCA LMO all are much too risky for amateurs to play with anywhere near a living space, especially in a mobile context.
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11-21-2019, 12:52 PM
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#17
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Bus Nut
Join Date: Dec 2017
Location: Southern Maryland
Posts: 505
Year: 1986
Coachwork: Gillig
Chassis: Phantom
Engine: CAT 3208
Rated Cap: 87, says Gillig...
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Quote:
Originally Posted by john61ct
Yes that is exactly what I'm saying.
LCO NMC NCA LMO all are much too risky for amateurs to play with anywhere near a living space, especially in a mobile context.
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We "amateurs" who choose to "play" with EV batteries are clearly incapable of doing so safely; so says the official skoolie.net lord god of solar. I yield my time back to John...
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11-21-2019, 01:09 PM
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#18
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Bus Geek
Join Date: Nov 2016
Posts: 2,775
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All the Lithium Manganese and Lithium Cobalt based chemistry cathodes have major negative temperature coefficient issues.
The car manufacturers spend millions on active liquid-based TMS designed by professional engineers to ensure the battery packs are maintained within a safe temperature range.
By amateur I mean everyone else, and certainly not meant to disparage.
But pulling packs out of scrapped vehicles removed them from those protective systems, and there aren't many even qualified engineers I'd trust to reverse-engineer the latter.
Not to mention BMS issues, ensuring multiple levels of failsafe HVC / LVC at the cell / group as well as pack- voltages,
and then the last-ditch temperature cutoffs at both ends, needed both for safety and pack longevity.
A set of LFP prismatics is not just safer but so much simpler to implement, why would you want to use any other LI chemistry?
Saving a few bucks is not a good enough reason.
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11-21-2019, 01:30 PM
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#19
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Bus Geek
Join Date: Nov 2016
Posts: 2,775
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Especially given the fact that even a brand new from the factory EV pack (unobtainium) will have 90+% less cycle longevity than an LFP bank.
Makes the cost of LFP per Ah per year actually much much lower, even if you **were** able to properly engineer all the protective systems.
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11-22-2019, 12:38 PM
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#20
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Bus Crazy
Join Date: Apr 2019
Location: SW USA
Posts: 2,064
Year: 2003
Coachwork: IC / Amtran
Chassis: CE300
Engine: International T444e
Rated Cap: 23
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Well, I've come full circle.
I'm going to build my own LFP battery after all. Been reading up on the topic since making this post & it appears to be within my capabilities. Plus it sounds like a lot of fun.
2p8s of CALB 100h prismatics, for ~200AH @ 24V. Even when topped off w/ a spendy BMS it prices out to about what a comparable AGM bank would cost, at almost 1/4 the weight. And about $1300 less than the Battle Born batteries of the same capacity, without the excessive parallel connections.
Best of all, while the bus is parked here in the summer, I can easily just pull the pack & bring it inside.
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