144v 100ah Lifepo4 Lithium Polymer Car Battery
This makes the 400Ah LFP financial institution approx four hundred kilos lighter than the equal usable capability in lead acid. Compare the above cell block from Ali-xxxx to the photo beneath of a Lithionics drop-in battery.
CALB cells for instance are rated at 1C / 77F so a 400Ah bank ought to ship 400Ah’s with 400A load at 77F. Lead acid batteries do not like to deal with excessive discharge masses similar to inverters. When you apply a load bigger than the 20 hour Ah ranking the capacity of the financial institution gets smaller.
Please understand that any voltage below the a hundred% SoC level, of the LFP battery, wouldn't be thought-about “floating” it. If utilizing a standby voltage at say 3.35V per cell, the current into the battery will find yourself at 0A and be slightly under the one hundred% SoC point. Look at any of your tablets, cell phones iDevices and so forth. and they all terminate cost when the battery is full. They reduce in when battery terminal voltage has fallen to a preset degree, however they don't maintain a excessive voltage on a full battery. Cell drift is why particular person cell level monitoring, of per-cell voltage, is necessary in a good pack design.
There is a large variance in the high quality of LiFePO4 drop-in batteries. He just ordered it based on it’s 8D format, the claim that it was ean exact drop-in substitute for his lead acid 8D battery and the 300Ah rating.
In the first 50 cycles I truly noticed a minor bump in capability. What this implies is a 400Ah LFP battery rated at .5C can deliver all 400Ah’s at a 200A steady load.
This battery makes use of impeccably matched aluminum encased LiFePO4 cells. The cells are mounted in place by a molded jig that protects them from motion and vibration failures. The busbars are excessive grade nickel plated copper and self locking flange nuts are used to carry the cells to the busbars. The BMS used on this battery is actually FET based mostly however it is made right here in the USA and is designed to handle starting engines.
He additionally nonetheless had the temp compensation circuit lively, something that's completely not good for LFP. Stupid charging practices, like using an automotive battery charger on a ship, can wind up with a state of affairs like this. Less than half the burden of lead, Ah to Ah, and almost all the time extra compact. The 400Ah financial institution on this article weighs 134 kilos less than a 400Ah lead acid financial institution. However, to equal the usable capacity of a 400Ah LFP financial institution, on my own boat, I would have wanted approx 900Ah’s of lead acid.
Pack voltage alone tells you nothing about an individual cell going off early, solely what the overall pack voltage is. A good BMS will reduce off charging properly earlier than any damage may be carried out to a person cell. In other words he was technically over-charging his bank earlier than he even got to 14.2V, because cost fee additionally performs a job. Once his financial institution hit 14.2V the charger then continued to cost them for 4 more hours every time he went to a hundred% SoC.
Do the mathematics on a $$ to cycles calculation and you will notice that LFP wins. When doing this math do not forget that a 400Ah LFP banks has usable Ah’s when out cruising and you can simply get back to 100% SoC. To get 320 usable Ah’s from a lead acid financial institution, when out cruising, (biking between 50% & 85% SoC) you would need approximately 900Ah’s of result in equal the 400Ah LFP bank. If you'll note above that only considered one of these cells delivered it’s rated capability, cell #1. The loses of capability are probably due to the vendor utilizing bargain basement, low high quality internals.