Battery ideas

[Mr.G]

I was thinking about dividing the ES into two batteries block which would be capable to operate like parallel or as two independent batteries to ensure capability to simultaneous charge and discharge to the pack.

Then I realized, what if the ES is divided into even more small blocks where each small block have an electronic circuit which will operate like some kind of switch with hysteresis.

- I've imagine system with two buses (charge and discharge) and the return (so 3 power wires).
- Each line will have current sensing circuit to monitor the current demand for discharge / ability to charge.
- Whole ES will be created from small battery blocks (cells) which are connected to both of these buses through a control circuit.
- The circuit on each battery cell will monitor the voltage level (charge level) and will automatically connect the battery cell to the representative bus (to charge bus when the cell is empty or to discharge bus when the cell is charged).
- The circuit will also maintain hysteresis of the connecting to a bus. Thats mean while the cell is about <30% of capacity it will be automatically connected to charge bus and stay there till it's charged at least to 80% or more.
- All battery cells will be interconnected with CAN interface.
- A master control unit will monitor all the cells and also the energy demand / ability to charge.

In such system you will be capable to simultaneously charge and discharge the ES and also you are protected of losing the whole ES if some of the batteries die (this cell will be disconnected from both buses). Regarding to the circuit I think it's not to hard to have some FETs / IGBTs and few OAMPs and small MCUs for the battery cells.

[NTS]

I was thinking about dividing the ES into two batteries block which would be capable to operate like parallel or as two independent batteries to ensure capability to simultaneous charge and discharge to the pack.

Why? There is a loss associated with putting energy into a battery and taking it back out. And also in the necessary AC/DC conversion and back. So if possible you would always use the energy from the generating component directly into whatever other component is asking for energy an only put the excess into the battery or take extra from the battery when the supply and demand don't match.

Then I realized, what if the ES is divided into even more small blocks where each small block have an electronic circuit which will operate like some kind of switch with hysteresis.

All large batteries are actually make out of a set of connected small cells. Google for how the battery-pack in a Tesla car works for example.

[Mr.G]

I know battery is made from cells, but the electronic on the cells is what matters to make a difference.

Regarding to the first point - yes you can still maintain the "shortcuts" for direct power delivery. Problem is I don't know the "numbers" for the ES usage. It may be that way that there is no need to have such system as I describe, but on some point it can be useful (or not )

[flynfrog]

You are sort of describing auto balancing and is pretty common for Li chemical battery packs. Its done more to keep all of the cells in the pack at the same level or charge or balance. As pointed out earlier it does not make sense to use and charge at the same time. You either have net energy into the pack our out of the pack never both I cant think of any advantage to doing on a per cell basis.

[WhiteBlue]

The basic problem is the discrepancy between power and energy density of the different types of storage devices. So far the best performance compromise is reached when bunching ultra caps and conventional lithium iron or phosphate cells together. Red Bull did that. You have to deal with the higher complexities of such a split system, but you do get performance gains from it. The stupid thing in F1 are the rules which introduce many unnecessary limitations which you do not find in LMP1. Hence we will see the more interesting solutions there.

[Greg Locock]

Good to see f1 innovating. we ran 2 battery types for good reasons in 1993

[autogyro]

Good to see f1 innovating. we ran 2 battery types for good reasons in 1993

Didn't one come from a sponsorship deal Greg?

[trinidefender]

I was thinking about dividing the ES into two batteries block which would be capable to operate like parallel or as two independent batteries to ensure capability to simultaneous charge and discharge to the pack.

Then I realized, what if the ES is divided into even more small blocks where each small block have an electronic circuit which will operate like some kind of switch with hysteresis.

- I've imagine system with two buses (charge and discharge) and the return (so 3 power wires).
- Each line will have current sensing circuit to monitor the current demand for discharge / ability to charge.
- Whole ES will be created from small battery blocks (cells) which are connected to both of these buses through a control circuit.
- The circuit on each battery cell will monitor the voltage level (charge level) and will automatically connect the battery cell to the representative bus (to charge bus when the cell is empty or to discharge bus when the cell is charged).
- The circuit will also maintain hysteresis of the connecting to a bus. Thats mean while the cell is about <30% of capacity it will be automatically connected to charge bus and stay there till it's charged at least to 80% or more.
- All battery cells will be interconnected with CAN interface.
- A master control unit will monitor all the cells and also the energy demand / ability to charge.

In such system you will be capable to simultaneously charge and discharge the ES and also you are protected of losing the whole ES if some of the batteries die (this cell will be disconnected from both buses). Regarding to the circuit I think it's not to hard to have some FETs / IGBTs and few OAMPs and small MCUs for the battery cells.

There would never be a case like this. If there is a situation where you are taking energy out of the ers-h and want to both put it every into the battery pack and drive the ers-k then you do that. If you want to use all to drive the ers-k then bypass the battery and put the energy straight into the ers-k. Or if you are braking and want to keep the turbo spooled then you take energy from the ers-k and while some goes to the battery the rest is sent to the ers-h to keep the turbo spooled.

What situation would you ever need to charge and drain the battery pack that can't be sorted out by just bypassing the battery pack altogether and send the energy from the source straight to load.

[Mr.G]

Yes, I realised that later, but I was too late
I was more focused on the idea of the "two way" baterry storage, than of the current rules.

I think the system as I described may work, but is not good solution for today F1.

[langwadt]

Yes, I realised that later, but I was too late
I was more focused on the idea of the "two way" baterry storage, than of the current rules.

I think the system as I described may work, but is not good solution for today F1.

I don't see how there would ever be a case you would charge and discharge at the same time
it would be like borrowing money to save up

it either you have too much energy or too little energy, if you have too much you charge, too little and you discharge

[Greg Locock]

Good to see f1 innovating. we ran 2 battery types for good reasons in 1993

Didn't one come from a sponsorship deal Greg?

No I think we paid for both. Less enigmatically, the rules for the 1993 solar car race were that you could have 5 kWh of batteries. We worked out that since we could expect a charge in the evening and morning of perhaps 1.5 kWh that we could get away with a 2kwh rechargeable battery (gates gel lead acids) and 3 kWh of lithium dry cells, from SAFT. This gave us the 5 kWh battery for about the same weight as the best at the time (silver zincs) for a fraction of the cost.

We were allowed to race with that combination but the use of primary cells was made illegal thereafter. So for the next race we used silver zincs and supercaps. After that of course LiPolys came in and battery choice became a non issue.