NERDville Project J-Who?!

hbpowerwall

hbpowerwall

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One of the elements of these projects that I find wasteful is the charging and discharging of the cells. Can I suggest that the charging is done by a solar/wind/hydro input option, that the discharging current is used productively to run the system via storage to a battery pack and that that pack can then be used to run the arduino/diagnostics element of the system!

Viva Jehu!

R.
 
Youngseal said:
One of the elements of these projects that I find wasteful is the charging and discharging of the cells. Can I suggest that the charging is done by a solar/wind/hydro input option, that the discharging current is used productively to run the system via storage to a battery pack and that that pack can then be used to run the arduino/diagnostics element of the system!

Viva Jehu!

R.
Click to expand...

charging with solarpanels/turbine is a good idea.
But your idea on discharging comes with i problem that your load is not constant.
correct me if i am wrong.

Lux,
 
The best sugegstion that has come from this is to charge the following cells with the ones that are discharging, which is a KICK-Ass idea. Think about it, your speeding the the whole process up by some 50% as your not only discharging one cell but your charging the other. The main hurdle here is to discharge at a constant 1A, but what if the cell your charging has just started or just finishing, the current is greatly reduced here. My thoughts are to distribute this discharging currennt over 4 cells. OR have the surplus current to make up the 1A sent to a MOSFET, which is the bit of energy you waste. I think that to me sounds like a compromise both on the electronics as well the recycling of the stored energy. SHARE YOUR THOUGHTS
 
I am noe electronics guru but the idea of using the discharge current of 4 cells would give a more usable energy to charge another cell or 2.
 
I have the Revolectrix PowerLab8 and they designed it with the option of being powered from a battery bank. It is admittedly more expensive than the IMax or similar chargers, but you can charge and discharge at over 1kW back into the battery bank to recover some of the energy. It also can balance charge 8s up to 3A per node.
 
BRIEF Update.

I've been busily working on this project and touched base with a few other YouTubers who are ahead in the game with the electronics. I'm hoping to share some exciting news on my next Youtube update for Project Jehu

I've been mainly exploring The Grid design and have made a scale prototype, which I was not happy with at all. My main concern was lack of ventilation and so have redesigned this so that the cells are more open to allow for air to ventilation easily and keep the cells cool during charge and discharge.

Check out some pics and they will be updated on my Channel.

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some more pics.

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this will be the new design i'm testing:


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It's funny you should say that. Didn't want to say it but may as well as this is a great forum. Me and Chris are Collaborating Projects to make the ULTIMATE charger. Hopefully will announce this shortly on the channel very soon. There are a few other engineers who have offered help which means the project is finally taking momentum.
 
I have two thoughts about the new grid design.
1) Make the top and bottom sides solid plastic, if you make it too open the fans will only cool the nearest cells and nothing else. Would keep dust and muck out of it also.
2) Bevel the edges of the holes so cells are much easier to drop in.
 
Hi :) I love this project and will help however I can. I think the concept chosen is by far the best. I understand you guys must be busy, festive season and all but I would love to see an update on general progress :)

Reducing power consumption is important to me as it will be running on a boat and minimising power usage is critical! Discharging from charged batteries is brilliant.

Is the plan still to use a minimal amount of TP4056's (maybe one - Increased time 30 fold, but accurate mAH - I am struggling with this), or some other way of uniform charging to prevent discrepancies in mAH with different chargers/dischargers, or is this something that has already been addressed?

As posted on one of NERDville's Video, but thought I would add it here - When the lid is lifted you wont be able to see the LED's. and will have to close the lid to check and reference which may be dead/charging/discharging. Probably not a big deal, but may make it easy for user error and/or excessive opening/closing lid. Possible fixes - Reference numbers or LED's on both the lid and next to batteries? See through lid with LED's next to batteries?
 
The problem with discharging cells to charge more is that current runs down hill as it were. As the battery discharges the voltage drops and as it charges it goes up so what you end up with is the transient current dropping to 0 as the batteries equalize in voltage (somewhere around 3.5V probably), this is effectively battery balancing.

Maybe with some clever circuitry you could use the beginning of discharge to initial charge a cell but it wouldn't be much, you'd still need a charging circuit and you'd be making it much more difficult to measure the discharge current accurately. We're not really talking about much power here either, for a 2200mAh cell, 4.2V x 2.2Ah = 9.24Wh (upper limit as voltage drops over discharge), for perspective this is a 1kW kettle running for about 3 seconds. Even over 6000 cells this is only 60kWh or about 7.50 and these cells are going to "save" that much energy every complete cycle for 100+ cycles so losing that little bit of energy would only account for an additional 1% efficiency loss still far better than a coal/gas station when you assume solar/wind is 100% efficient.

I also don't think this keeps with the KISS mentality. I thought 1.0 was awesome, 2.0 was novel, but when 3.0 was shown I could immediately see it was going to be the superior solution. Probably the best use for the discharge energy is going to be as a 60W fan heater in the shed ;)
 
pelecypod said:
The problem with discharging cells to charge more is that current runs down hill as it were. As the battery discharges the voltage drops and as it charges it goes up so what you end up with is the transient current dropping to 0 as the batteries equalize in voltage (somewhere around 3.5V probably), this is effectively battery balancing.

Maybe with some clever circuitry you could use the beginning of discharge to initial charge a cell but it wouldn't be much, you'd still need a charging circuit and you'd be making it much more difficult to measure the discharge current accurately. We're not really talking about much power here either, for a 2200mAh cell, 4.2V x 2.2Ah = 9.24Wh (upper limit as voltage drops over discharge), for perspective this is a 1kW kettle running for about 3 seconds. Even over 6000 cells this is only 60kWh or about 7.50 and these cells are going to "save" that much energy every complete cycle for 100+ cycles so losing that little bit of energy would only account for an additional 1% efficiency loss still far better than a coal/gas station when you assume solar/wind is 100% efficient.

I also don't think this keeps with the KISS mentality. I thought 1.0 was awesome, 2.0 was novel, but when 3.0 was shown I could immediately see it was going to be the superior solution. Probably the best use for the discharge energy is going to be as a 60W fan heater in the shed ;)
Click to expand...

i really like your idea of heater as a load.
maybe you can put the load resistors on a aluminium plate and place your coffee or tea on it so it keeps it warm :D
 
You seen the videos on the "davidcandlelight" channel ?
Would be an alternative to 3D printing, for those that don't have access to one.
He had someone laser cut Plexiglas sheets.

Battery pack with replaceable cells
Construction / teardown
 
 
 
Hey nerdville,
No updates on your work? Im really curious:)
 
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