Lithium Batteries, who has them?

[Izabarack]

Regarding mounting or installing of individual cells, can LiFePo cells be mounted on their side like gell cells?

Iza

[T1 Terry]

Regarding mounting or installing of individual cells, can LiFePo cells be mounted on their side like gell cells?

Iza

No idea where this post went, but take 2
This depends on the cell type, cylindrical cells can generally be mounted any which way because they do not have a fluid electrolyte as such, pouch cells can be laid flat generally because the electrolyte is trapped in the individual packages. Prismatic cell can be mounted on their skinny side or up the right way only, not on their fat flat side or upside down. The reason for this is the electrolyte is fluid and the separator is one long sheet wrapped between the 2 active plates to keep them apart, but also allow the electrolyte and therefore the lithium ions to pass from plate to plate. Laid on their flat side would allow the plates on the top to dry out, no electrolyte, no lithium ion movement resulting in lost capacity. Apparently it does return when mounted the right way up again, but I've never tried that one.

T1 Terry

[dapope]

Mine have been on the flat side for the last 8 months, however will go to skinny sides next and see what happens

[T1 Terry]

The next episode:
An LiFe lithium battery can be made up in different ways using different cell types (naturally the same type throughout the battery) and different capacity cells. Cylindrical cells, pouch cells and prismatic cells are different forms of cell but still the same chemistry. As few photos so you can better identify what they look like so a mental picture can be formed when a certain type of cell in mentioned.

18650 cylindrical cells.jpg

18650 cells built as a battery.jpg

Pouch cells.jpg

pouch cells built up as a battery.jpg

prismatic cells.jpg

prismatic cells assembled as a battery.jpg

All of these types can and are used to build LiFe house batteries, yet not all are suitable for the job. Cylindrical cells are best suited for propulsion use, they have a high discharge rate and high charge acceptance rate, great for an electric vehicle, of no real benefit for house battery application. These are the type of cells used by Tesla, a different chemistry but still the same oversized torch batteries, just lots of them and they fluid cool/heat them to keep them within their happy operating range.
House batteries don’t need a high discharge or recharge rate, what they need is stability over the temp range people find bearable without needing special heating or cooling set ups and long cycle life, pouch cells and prismatic cells fit into this category. The next thing is they need to be easily accessible and easy to handle if a cell needs to be changed for whatever reason. Let’s face it, mass produced products are going to have a few failures slip through the quality inspection process and accidents can happen and a cell or a few cells may get damaged. The advantage with LiFe batteries built up from single cells is an individual cell can be replaced if it fails, much cheaper than the whole battery. This puts pouch cells out of the game due to the complicated connection process, so prismatic cells are by far the most suited to this application. No doubt I am now on a few battery resellers hit list after revealing this bit of information as their product doesn’t fit this description.
Tomorrow, what size cells builds a better battery and what needs to be done to prepare the cells for use as a house battery.

T1 Terry

[Dot]

= shite M8

[Izabarack]

No idea where this post went, but take 2

Thanks Terry. I have prismatic and the question was more to understand options in how and where to mount. A bit of forward planning for as soon as the current AGMs GoFinish.

Iza

[T1 Terry]

No questions, no comments? Am I getting to techo or not techo enough?

T1 Terry

[generdawg]

No questions, no comments?

Not sure if this fits here. If not, please feel free to relocate post.

You may recall that I would like to fit lithium, but have postponed the exercise until the AGM's are near death.

I would like the advantage of having enough battery power to run the aircon during the night.
Also recall that my solar real estate is minimal.

So my question is; would it be practical to install enough lithium, complete with the switch gear and accessories to run the aircon and make up what the minimal solar supply lacks with daytime generator (EU20i) charging if necessary?

dawg

[SteveW]

Don't be fooled by the silence, Terry. I am listening intently - but not qualified to make comment.

[Mrcoolabah1au]

Ok how do we become qualified?