Re: [electricboats] 15 KW DC l electric conversikon

I will send pictures. I found some great plastic heavy duty battery boxes at a marine supply store. Try west marine. Very sturdy boxes designed for batteries. I also found a husky storage box at Home Depot. I used in my golf cart project   Nice size for 12 v set up. mil thickness is 7 shrink wrap.  Used for covering large cargo for transport   

​Terminalift LLC

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Santee, CA 92071

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On Sunday, February 9, 2020, 6:10:53 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 things like electric bikes; i.e. shrinkwrapping.

ABYC standards require that the batteries be enclosed and insulated from potential short circuiting, requirements which it seems your approach probably fulfills.  You might try sending them an email asking the question, though.  I found them to be responsive.

Do you have four separate BMS units, or are your 12v modules tied together into one system?  Are you 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 breaking apart the pack so I can disconnect and carry 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 I understand is important for preventing the internal structural changes that can arise inside an expanding cell.  Do you feel the shrink-wrapping 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]