I have been experimenting with battery assembly projects for a couple years. My first opportunity was an electric forklift upgrade from lead acid to lithium iron phosphate The project really opened my eyes to the benefits of the battery chemistry. It was the golf cart upgrade that made me rethink battery installation for water proof. A few drops of overnight rain instantly corroded the lithium. I have used heat shrink on large objects for shipping . 7 mil blue roll material is very robust. Uline has it. Used after assembly before install. My battery boxes were bought to fit the 16S4P assembly It is important to fit a couple of space fillers between your batteries and box side. I shaped foam to fit snug. Thank you for your interest. Cheers
Terminalift LLC
9444 Mission Park Place
Santee, CA 92071
Ph: (619) 562-0355
F: (619) 562-2060
On Sunday, February 9, 2020, 6:11:01 PM PST, THOMAS VANDERMEULEN <tvinypsi@gmail.com> wrote:
Larry,
Really interesting information.
I'm very curious about your sources of materiel (batteries, boxes, BMS, etc) and about your overall design & approach.
In particular it's interesting to me that you employed a waterproofing solution similar to what's used for small packs built from cylindrical cells for thinks like electric bikes; i.e. shrinkwrapping.
ABYC standards require that the batteries be enclosed and insulated from potential short circuiting which it seems your approach probably fulfills. You might try sending them an email asking the question. I found them to be responsive.
Do you have four separate BMS units, or are your 12v modules tied together into one system? Are monitoring individual cell voltages? I'm curious about how you're connecting the sensing wires to the batteries. Does your BMS also implement cell balancing? Are you monitoring cell temperature in any way?
I'm using 16S x 200Ah LiFePO4 prismatics and have also chosen to segregate them into four 12v units. I'm running the sensing wires through waterproof (Molex) connectors, one connector per 12v group, to facilitate disconnecting and carrying each 4-cell package off the boat for winter storage or servicing.
I've built my 4-cell units into boxes to constrain the cells from expanding during charging and discharging, which understand is important for preventing the internal structural changes that can arise inside an expanding cell. Do feel the shrinkwrapping you used is strong enough to accomplish this, or did you use constraining plates of some kind inside the package?
I have not yet found a correctly sized box to hold four of the 200Ah CALB cells I'm using. What are the interior dimensions of the boxes you are using? Are they hard plastic, or HDPE instead, & wall thickness, plz?
I hope you're not annoyed at all the questions!
[-tv]
Thomas VanderMeulen
"Grace O'Malley"
Cape Dory 27
Monroe, Michigan
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