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Howesight
Samba Member
Joined: July 02, 2008
Posts: 3274
Location: Vancouver, B.C.
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 Posted: Tue Mar 23, 2021 2:40 pm Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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Guys, don't forget that the aluminum jacket on the LiFePo4 cells that is covered by the blue plastic IS ATTACHED TO ONE OF THE CELL TERMINALS ON EACH CELL. The blue plastic is, thus, an insulator.
Installing these cells in a vehicle that pitches, sways, bumps and grinds means that the blue plastic insulation can easily be abraded away when rubbing against metal or other coarse/pointy/abrasive materials.
I realize not everyone buys in to the benefits of compression plates on the LiFePo4 batteries, but the larger the cells, the greater the need for and benefit from compression plates. Obviously, the plates increase the physical dimensions of your battery and make an under-the-driver-seat installation impossible for the 280Ah class. FWIW, I keep my stock of spare parts and emergency bits (zap straps, tire repair kit, ign coils, light bulbs, ign. switch, hardware, gorrilla tape, etc) under the driver seat. If I have a failure requiring access to these items, they are all in one place, not in various crevices and nooks.
This insulation aspect is important. I would hate to see LiFePo4 installations result in a spike in the current rate of Burnt Vanagon Syndrome.
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'86 Syncro Westy SVX |
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fxr
Samba Member
Joined: December 07, 2014
Posts: 2325
Location: Bay area CA
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| Posted: Tue Mar 23, 2021 3:08 pm Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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There is just room lengthwise to allow thin 'cutting board' separators in that position and one underneath. It's the height that's the problem, especially once even the thinnest of connectors is bolted to the terminals. The seat (OK, an OEM seat might be different) would have to rise by at least an inch. That creates a literal head-room problem...
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Jim Crowther
1984 1.9l EJ22 Westy Wolfsburg Edition
Vespa GTS 300 |
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MayorMcCheese
Samba Member
Joined: October 07, 2009
Posts: 659
Location: Lancaster PA
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| Posted: Tue Mar 23, 2021 5:14 pm Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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| Surely it's the ground terminal that's attached to the outer casing. |
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dobryan
Samba Member
Joined: March 24, 2006
Posts: 16503
Location: Brookeville, MD
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fxr
Samba Member
Joined: December 07, 2014
Posts: 2325
Location: Bay area CA
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| Posted: Tue Mar 23, 2021 5:50 pm Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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| MayorMcCheese wrote: |
| Surely it's the ground terminal that's attached to the outer casing. |
It's the positive terminal of each cell. That is also connected to the negative of the cell up the chain in the battery. So two adjacent cells have 3.2V between their respective outer casings and almost zero resistance in the cell - these casings must NOT touch, and none of them must touch the chassis!
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Jim Crowther
1984 1.9l EJ22 Westy Wolfsburg Edition
Vespa GTS 300
Last edited by fxr on Wed Mar 24, 2021 9:27 am; edited 1 time in total |
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kguarnotta
Samba Member
Joined: April 01, 2004
Posts: 1160
Location: Woodstock, NH
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| Posted: Tue Mar 23, 2021 5:52 pm Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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"...and under the rear seat is heated."
I put my battery under drivers seat. I like tucking it away - but did not realize how important keeping battery warm for charging time...
When i get into that again - I'll put it under the rear seat.
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-Kevin
Lincoln, MA
'86 Triple Knob Syncro w/EJ22
'78 Westy
'69 Single Cab
'65 Kombi - EZ-Camper |
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owokie
Samba Member
Joined: May 21, 2003
Posts: 533
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| Posted: Tue Mar 23, 2021 5:55 pm Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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| fxr wrote: |
| MayorMcCheese wrote: |
| Surely it's the ground terminal that's attached to the outer casing. |
It's the negative terminal of each cell. That is also connected to the positive of the cell down the chain in the battery. So two adjacent cells have 3.2V between their respective outer casings and almost zero resistance in the cell - these casings must NOT touch! |
False, the case is positive. The big issue would be cases contacting chassis, not each other. |
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Howesight
Samba Member
Joined: July 02, 2008
Posts: 3274
Location: Vancouver, B.C.
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| Posted: Tue Mar 23, 2021 6:09 pm Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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I couldn't recall, when writing above, what the polarity of the aluminum case was, but they definitely need to stay insulated from each other and from any other metal.
Fxr: Good to know the 280 class cells will fit with a high-mounted seat. Some people can use a high-mount driver seat, but not me or Mrs. Howesight. She is a legitimate 6-footer and once you add the 'high hair" from camping hygiene - - well, you get the picture.
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owokie
Samba Member
Joined: May 21, 2003
Posts: 533
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| Posted: Tue Mar 23, 2021 6:30 pm Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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| Howesight wrote: |
I couldn't recall, when writing above, what the polarity of the aluminum case was, but they definitely need to stay insulated from each other and from any other metal.
Fxr: Good to know the 280 class cells will fit with a high-mounted seat. Some people can use a high-mount driver seat, but not me or Mrs. Howesight. She is a legitimate 6-footer and once you add the 'high hair" from camping hygiene - - well, you get the picture. |
Nice image. For clarity, there is not a "3.2v" delta between cell cases, there is a 0.0v difference if you're balanced. Cell to cell contact, you're just running a combination series/parallel circuit and dropping your overall pack voltage, right? Cell to chassis, yes, big problem, though one limited by your BMS on the negative side limiting flow. I was, granted, a B- physics student so anyone feel free to correct me, not that anyone around here needs permission. |
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shagginwagon83
Samba Member
Joined: February 07, 2016
Posts: 3800
Location: VA/TN
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| Posted: Tue Mar 23, 2021 6:39 pm Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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| owokie wrote: |
| I was, granted, a B- physics student so anyone feel free to correct me |
There is a flaw in your 'infinity battery' term, but that term convinced me to get one.
I have 150aH under the drivers seat. It feels pretty protected. However I'm gonna be ditching it and going with 310aH somewhere else. I really love the user who installed theirs next to westy water tank. I have my heater in that same area and think that would be a great spot!
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Brandon
"Jo Ann" - '83.5 Westfalia EJ22e w/Peloquin
Instagram @joannthevan |
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owokie
Samba Member
Joined: May 21, 2003
Posts: 533
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| Posted: Tue Mar 23, 2021 6:48 pm Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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| shagginwagon83 wrote: |
| owokie wrote: |
| I was, granted, a B- physics student so anyone feel free to correct me |
There is a flaw in your 'infinity battery' term, but that term convinced me to get one.
I have 150aH under the drivers seat. It feels pretty protected. However I'm gonna be ditching it and going with 310aH somewhere else. I really love the user who installed theirs next to westy water tank. I have my heater in that same area and think that would be a great spot! |
Good call. Also, me and your boy Jeff both have them by our water tanks, ain't no other spot.... |
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shagginwagon83
Samba Member
Joined: February 07, 2016
Posts: 3800
Location: VA/TN
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| Posted: Tue Mar 23, 2021 7:07 pm Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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| owokie wrote: |
Good call. Also, me and your boy Jeff both have them by our water tanks, ain't no other spot.... |
Well speaking of water he couldn't think straight for an hour after he received news there was a puddle under his LT 
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Brandon
"Jo Ann" - '83.5 Westfalia EJ22e w/Peloquin
Instagram @joannthevan |
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Howesight
Samba Member
Joined: July 02, 2008
Posts: 3274
Location: Vancouver, B.C.
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| Posted: Tue Mar 23, 2021 7:09 pm Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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I used to use the cubby next to the water tank for my shore power cord, 120V electric space heater, 12V air compressor and odds and ends. Now it houses the LiFePo4 battery, 60 amp fuses, and the low-amp fuse panel.
With 280Ah of LiFePo4 in the cubby and a CDH tucked tightly under the bench seat, I have no need for those items and cleared the lead-acid battery and VW rear heater out from under the bench seat. It's a net gain of space under the bench seat - - and I didn't have to sacrifice that precious space under the driver seat! 
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shagginwagon83
Samba Member
Joined: February 07, 2016
Posts: 3800
Location: VA/TN
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| Posted: Tue Mar 23, 2021 7:13 pm Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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| mikemtnbike wrote: |
| I'm pretty sure Shaggin is wanting his van to be a mobile danceravepartydiscopowerstationbar. Hence, 310ah. |
Damn right. But also, I was in a situation where I was camping for a week straight with little to no solar. I love the idea of letting engine run for 1 hour = 60ah. That essentially is a days worth of electricity.
Granted 60 amps is gonna put a hurting on that alternator! The 60amp DC-DC unit was same price as Victrons 30amp unit.
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Brandon
"Jo Ann" - '83.5 Westfalia EJ22e w/Peloquin
Instagram @joannthevan |
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ProspectiveOwnergon
Samba Member
Joined: May 22, 2020
Posts: 211
Location: SoCal
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| Posted: Tue Mar 23, 2021 8:07 pm Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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| Any reason to get the Renogy 50aDCDC vs the 30a? I am running the stock alternator and will only be plugging in 1/100w solar panel. Saves about $40. |
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xoo00oox
Samba Member
Joined: February 11, 2010
Posts: 2672
Location: East Nassau, NY
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| Posted: Wed Mar 24, 2021 5:49 am Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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| shagginwagon83 wrote: |
| mikemtnbike wrote: |
| I'm pretty sure Shaggin is wanting his van to be a mobile danceravepartydiscopowerstationbar. Hence, 310ah. |
Damn right. But also, I was in a situation where I was camping for a week straight with little to no solar. I love the idea of letting engine run for 1 hour = 60ah. That essentially is a days worth of electricity.
Granted 60 amps is gonna put a hurting on that alternator! The 60amp DC-DC unit was same price as Victrons 30amp unit. |
Do you think it would overheat the alternator by continuously pulling 60 amps? |
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vwhammer
Samba Member
Joined: May 20, 2006
Posts: 998
Location: Boulder CO.
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| Posted: Wed Mar 24, 2021 6:33 am Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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So this would not work for drivers seat in vans that have cabinets but has anyone considered bumping the back wall out a bit to fit the 280ah cells or bigger?
Perhaps then they can be laid on their side with all the terminals pointing backwards. and no fear of shorting on a seat.
I am considering trying this out when it comes time to buy and mount my batteries.
it's a pretty flimsy bit of sheet metal and you could just bump out the whole area to make a sort of false wall were wiring and the like could be hidden.
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Pretty normal daily driver build
https://www.thesamba.com/vw/forum/viewtopic.php?t=708418&highlight=
4x4 build
https://www.expeditionportal.com/forum/threads/volkswagen-vanagon-4x4-conversion.162055/ |
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erste
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Joined: March 29, 2013
Posts: 1110
Location: San Francisco
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fxr
Samba Member
Joined: December 07, 2014
Posts: 2325
Location: Bay area CA
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| Posted: Wed Mar 24, 2021 9:27 am Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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| owokie wrote: |
| fxr wrote: |
| MayorMcCheese wrote: |
| Surely it's the ground terminal that's attached to the outer casing. |
It's the negative terminal of each cell. That is also connected to the positive of the cell down the chain in the battery. So two adjacent cells have 3.2V between their respective outer casings and almost zero resistance in the cell - these casings must NOT touch! |
False, the case is positive. The big issue would be cases contacting chassis, not each other. |
Corrected, thank you! 
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Jim Crowther
1984 1.9l EJ22 Westy Wolfsburg Edition
Vespa GTS 300 |
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buspor63
Samba Member
Joined: February 17, 2005
Posts: 1179
Location: Knoxville,TN Where America stops for gas
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| Posted: Wed Mar 24, 2021 8:34 pm Post subject: Re: LiFePO4 Batteries: Discussion Thread |
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| Howesight wrote: |
I think that using up that 310Ah will be more of a chore than re-charging. So far, I am not seeing any appreciable net discharge in my 280Ah battery, but it is early days and I have just been running my TF-65 fridge at 25F plus some use of my CDH. But so far, I am seeing that I would really have to work at creating loads that would use up the 280Ah of capacity. I suspect that the 30 amps from the Victron might well be enough
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So, what I gather here is, spend more on batteries and the DC/DC and skip the solar and solar charge controller.
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Imagine that, theres not an "h" in either Westfalia or Syncro? |
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