Lithium batteries explained. gas variables pogil answers

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First part: Cranking performance. LFP has linear power delivery between 10% to 90% state of charge (SoC), a usable cranking range of 10% to 100% SoC, Lead acid, by comparison, has non-linear current delivery and a usable range between from 50% to 100% SoC. Furthermore, we have to consider the charge interface. This is the amount of current which the battery will deliver or receive. (Read my previous post about charging rates and optimal performance.) Which is 2C (200% of capacity) for LFP and C/5 (20% of capacity) for AGM. Now, because the optimal charge interface for LFP is greater than capacity this means that all of the capacity is available, compared with just 20% of the AGM. Then we apply this to the usable capacity. this means that the LFP can crank all the way down to 10% SoC, however, the AGM is limited to just 20% SoC at a time, it then needs recovery time before it can perform again. This all means that LFP cranks better when compared with AGM.

Second part: Loss improvement. The current flow rate in and out of the battery is governed by the batteries internal resistance. The current flows easier into and out of the LFP, because of its lower internal resistance when compared with AGM. This lower resistance also means that alternator becomes more efficient, in doing so it reduces the load on the engine. Therefore more power to the back wheel. la gas prices A small gain, but still gain. The mass of LFP can be kept low because of the larger usable range advantage which I explained in the previous post. With this reduced mass there is further small gain, as this improves the power weight ratio.

Oh, and wait until Lithium Nano-carbon becomes a thing. This will blow away all another lithium-ion tech. It will be the energy storage solution which will cure the range issue for electric vehicles. And solve the problem for usable renewables such as wind, solar and tidal power. but we are 5-10 years away from a point where this will be affordable.

Second part: Loss improvement. The current flow rate in and out of the battery is governed by the batteries internal resistance. The current flows easier into and out of the LFP, because of its lower internal resistance when compared with AGM. This lower resistance also means that alternator becomes more efficient, in doing so it reduces the load on the engine. Therefore more power to the back wheel. A small gain, but still gain. The mass of LFP can be kept low because of the larger usable range advantage which I explained in the previous post. With this reduced mass there is further small gain, as this improves the power weight ratio.

Part Three: Reliability. A battery’s life expectancy is expressed in the number of cycles. This is how many times it can be discharged and recharged again. The deeper it is discharged the shorter its life becomes. We use Depth of Discharge (DoD) for this rather than State of Charge (SoC). However DoD is just the inverse of SoC. As such, 10% DoD is 90% SoC. 50% DoD is 50% SoC, 90% DoC is 10% SoC. types of electricity tariff Got it? For AGM you can cycle to 20% this is several thousand times. (This is what makes them suitable for starter applications.) However to 50% DoD this drops to between 150 and 300 cycles. And 10% DoD this plummets to just a handful of times. This reduction is caused by the creation of lead sulfate. Lead Sulphate is a crystal structure. Deeper discharge creates more crystals, increased time create larger crystals. Larger crystals are harder to break down, which makes the battery harder to recharge. They’re also brittle and can snap off from the plates. This process is called Shedding. This crystal formation and shedding reduce the amount of available reactive material. Therefore reducing the battery’s capacity. Eventually lowering it too far for it to continue delivering current at an effective level. Also, these crystal need space to expand into, this causes plate distortion. If the plate distorts too much, it puts positive and negative plates into contact with one another. It forms a short circuit and makes the cell inoperative. This turns a 12V battery into a 10V battery. Making instantly useless! Now, let us look at LFP: To around 20% DoD this is more than twice that of AGM. k electric bill statement Even when you take LFP to 90% DoD you can still get between 2,000 – 3,000 cycles. Which, as you can see, is significantly higher than AGM. LFP battery structure is also better than AGM: AGM uses six 2V cells in series to make 12V. LFP uses sets of cells in parallel, with for sets of 3.2V cells in series to make 12.8V. If one cell in that parallel set fails then it only loses capacity. There is rarely a short, so it still remains at 12.8V. and therefore functional. gasbuddy touch LFP batteries have a higher voltage in which they become inoperative. Normally this is around 8-10V, whereas AGM can be recharged from as low as a few millivolts. To solve this high problem LFP use a battery management system (BMS) but I will cover that in my next post. So, in short, LFP is more reliable when compared with AGM.

Part Four: Problems. Temperate – Battery performance is affected by temperature. At 20°C both lead acid and LFP work very well. However, the colder it becomes, the slower the chemical reaction. An LFP battery does not work well in low temperatures, the current delivery from them is a small fraction of maximum @ 0°C, and virtually non-existant at -20°C. Lead acid batteries work fine at very low temperatures. We express this ability under starting conditions with lead acid as Cold Cranking Amps (CCA). For the standard CCA:EN this is the amount current that the battery can deliver for 30 seconds and reach 1.2V per cell (7.2V in the case of a 12V battery) at a temperature of -20°C. (CCA:SAE is similar but as it is at 0°F/-18°C it gives slightly more amperes). LFP cannot be tested to any CCA standard, they do not work well at this temperature. Any CCA rating on an LFP battery is simply a guide for comparison to lead acid. However, there is a solution to this low-temperature problem with LFP. That is to heat the battery, this can be done by drawing current from it, either by attempting to start the bike at spaced intervals or by using a smaller load such as turning your lights on. How long this takes depends upon the load and the temperature. At an ambient temperature of 0°C it is normally 30 or so seconds of lights on. for -20°C it is several minutes even when using the starter for a few seconds and then waiting a couple of minutes before trying again. But for most of us, this is not an issue because we don’t ride in the cold… The next problem is capacity. This is an issue for both AGM and LFP, the motorcycle’s electrics have a load. Most of the time it is around 20mA to 30mA, sometimes higher, and rarely above 50mA. The LFP battery’s capacity compared to it’s AGM equivalent is normally around 25%. ie a 10Ah AGM would be replaced by a 2.5Ah LFP. So, the AGM will be able to stay within its SoC range for longer because its 0% SoC = flat (Static measurement is 11V for AGM, and 12.6 for LFP). Below this, the battery is considered deep discharged. The problem for the lead acid battery is lead sulphate crystal formation. Which I mentioned previously when discussing reliability. However, for LFP in a deep discharge state, there is a different problem. That is a high risk of fire. For fires to happen you need 3 things. A fuel, a source of oxygen, enough temperature to allow ignition to occur. When an LFP battery discharges the oxygen loses its bond. If you then attempt to charge the little amount remaining reactive material it can heat up very quickly. Lithium is a fuel. electricity a level physics So you have all of the ingredients for a battery fire. LFP is better than other Lithium-ion tech. but is it still a risk. Which leads me to my next post…

Part Five: Battery charging (Warning this section contains a shameless plug). Neither, LFP or AGM survive an overcharge. However, LFP will suffer permanent damage above 14.8V even if it is just for a short time. Above 15.3V some LFP batteries will instantly fail. AGM batteries will handle up to 14.7V without a problem. Over this voltage, an AGM will suffer from excess production is Hydrogen Sulphide gas (which goes bang quite well BTW). If the gas pressure becomes too high a valve is forced open, which vents off the excess gas. You may see AGM also referred to as Valve Regulated Lead Acid (VRLA). This venting will cause small losses in the electrolyte levels, which reduces the battery’s capacity. The motorcycles alternator output regulated to between 14.3-14.7V. Which ideal for both types. electricity history timeline But also worth checking to ensure you do not have regulator fault. So, both AGM and LFP are normally safe when in service. Now, what about when the bike isn’t being used. This is where correct battery support is needed using a suitable charger. Unfortunately, LFP and lead acid batteries have different requirements for long-term maintenance. LFP prefer being kept at around 70%-80% SoC, whereas lead acid is 90%-100% SoC. Outside of these ranges, a capacity loss can occur. Ideal voltages for the charger will be 13.2-13.3V for LFP and 13.4V – 13.8V for AGM. And too low a voltage will also create problems for both types. Recovery from heavily discharged states is also different, with AGM a higher voltage is required this overcomes the increased resistance of the lead sulphate crystals. With AGM below 50% DoD 15-16V is fine. However, for heavier lead sulphate formation, 20-25V is required. And in both cases, it needs to be carefully controlled. These voltages are far too high for LFP to handle, so lead acid chargers with correct recovery processes should not be used of LFP. Now for handling heavily discharged LFP you need to reduce charging current to around C/10 or C/20. This is to prevent damage or even fire. However, once the battery has raised above 10% SoC normal charging can resume. Well, this is assuming that the temperature is above 0°C. The smaller charge interface/less reactive chemistry at that temperature will just not handle the current. q gases componen el aire However, the battery will warm and start to pull more current once it has. And now for the shameless plug. www.OptiMate.co.uk this website is run by the company I work for. I know how the chargers work, and how batteries work too (as demonstrated in the above epic tome of comments). I can testify that OptiMate chargers work. For LFP you will need an OptiMate Lithium (either the 0.8A or 5A), and for AGM (or indeed any 12V lead acid motorcycle battery) you will need either OptiMate 3 or OptiMate 4.