thesillym
New Member
I have not attempted it yet, but I did send an email to battery hookup to ask how they did it. They are selling individual cells now.
60VDC Lifepo4 battery 20S 280AHr. I have two of these batteries, laser welded and already assembled in nice steel container with their BMS, Fan etc.
- Thread starter Jose Arias
- Start date
thesillym
New Member
Response from Battery Hookup
Hi once you get the straps removed around the battery and remove the bolts that are holding the outer compression plate in, you will need some leverage to pry it out. Imagine standing up one of the cells and knocking it over by pushing on the top of the battery. Like a book falling. We cut the busbars and the plastic between the cells with a dremel and cutting wheel. Then we slide a strap around the top corners and use a pole with some leverage to pull down and get the cells to break out. You first need to single out the cells and get that outer plate on (off?). The part that is holding the cells together is the glue on the base. You are essentially prying with enough pressure to break that bond. Usually the shrink wrap of the cell on the bottom will break off. You don't want to use anything that would dent the cells which is why we use the straps from a ratcheting strap. Next time we break one down I can get a quick video. It's all about leverage and not damaging the cells. Human strength is not enough without leverage on these since they are built so well.
It's a shame to destroy such a well-made battery pack like that. There's nothing wrong with it; you've got factory compression, cell support, cell isolation, flexible busbars, welded connections, balance leads—all prebuilt and done for you, with A-grade cells for around the price many sellers are selling bare B-grade (or worse) cells for, where you would then have to do all the work to assemble a pack.
Just use it at 60V! While more uncommon, it's a good voltage. I special-ordered a Genetry Solar 12kW 60v inverter to use with mine, because I noticed it has a 60v transformer winding ready to go for this voltage. They are going to send me a prototype unit (at full cost, in a couple weeks) as they need some real world data to ensure that all the electronics can handle the higher voltage in a range of real-world scenarios, after which they will start advertising this voltage as supported. If you can wait for that, I believe it would be a good option based on my experience with their inverters thus far. And as others have pointed out here already, there are several MPPT options that should be able to float it to the 70v needed to charge these packs.
If that is a no-go for you, then buy these packs in multiples of four (68kWh total), modify each pack using a dremel to carefully cut the busbar connecting the last four cells to the rest of the pack, bend both sides of that cut busbar up to give you tabs, drill a hole in both tabs, and run wires with ring terminals connecting the four sets of four disconnected cells in series with each other for a fifth 48v pack. This way, you still preserve all the benefits of buying these pre-made packs with just a little extra work required in connections. Last night, I randomly stumbled upon this YouTuber who documented his version of this approach (don't know who he is, just thought the video might give y'all some ideas): DIY Solar Powerwalls Build Seven for the Price of One Part 4.
Just use it at 60V! While more uncommon, it's a good voltage. I special-ordered a Genetry Solar 12kW 60v inverter to use with mine, because I noticed it has a 60v transformer winding ready to go for this voltage. They are going to send me a prototype unit (at full cost, in a couple weeks) as they need some real world data to ensure that all the electronics can handle the higher voltage in a range of real-world scenarios, after which they will start advertising this voltage as supported. If you can wait for that, I believe it would be a good option based on my experience with their inverters thus far. And as others have pointed out here already, there are several MPPT options that should be able to float it to the 70v needed to charge these packs.
If that is a no-go for you, then buy these packs in multiples of four (68kWh total), modify each pack using a dremel to carefully cut the busbar connecting the last four cells to the rest of the pack, bend both sides of that cut busbar up to give you tabs, drill a hole in both tabs, and run wires with ring terminals connecting the four sets of four disconnected cells in series with each other for a fifth 48v pack. This way, you still preserve all the benefits of buying these pre-made packs with just a little extra work required in connections. Last night, I randomly stumbled upon this YouTuber who documented his version of this approach (don't know who he is, just thought the video might give y'all some ideas): DIY Solar Powerwalls Build Seven for the Price of One Part 4.
thesillym
New Member
I just found that youtube channel this morning LOL. Battery Hookup posted a couple video of how they are separating the cells.
Could tell us more about the packs, like what voltage the pack was at, individual cell voltage. When you took these apart did you see any signes they are used; any dust on the fan blades, behind the bms, along the cooling air path, inside the cell seperators.
If these packs are new, unused they have been sitting for two years it will be interesting to see all the cell voltage levels. Also could you post pics of any data tags pack qr code or shipping tags, would be nice to know when they came across the ocean.
If these packs are new, unused they have been sitting for two years it will be interesting to see all the cell voltage levels. Also could you post pics of any data tags pack qr code or shipping tags, would be nice to know when they came across the ocean.
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Found the pack QR code on pics from supplier website, looks like cells made 4/21 packs assembled 5/21. Theses packs appear to be from large containerized ups running 17s 1088v or grid scale peak shifting systems for solar/wind farms. I wonder where they have been sitting for two years? Is there any labeling on the outer carton, and does the serial number match the pack numbers?
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