The original Winston LP12V80AH battery - after 3 years at 98AH!
The photo shows the LP12V 80AH battery produced by Winston (ThunderSky) in 2010. After 3 years of continueous use it gives 98 AH (!) of real capacity. After the warranty period, the battery was modified by the user to get access to each cell and to monitor the voltage of the cells, using the CellLog8.
What can be said? It seems better than “ideal dream”. But it is not a dream, it is the reality of the LFP technology. With LFP cells energy storage is possible!
Connecting LP12V batteries - serial and parallel
We always recomend to make paralel connection first before making the serial connection. With parallel connection the two (or more) batteries are managed (monitored) as one block.
The LP12V20AH battery with improved terminal connectors
For starting applications you can improve the performance of the LP12V20AH battery by using more robust copper terminals.
Replacing OPTIMA Yellow 65AH with 60Ah Winston LP12V60AH
The Chrysler Voyager (now Lancia Voyager) has the Optima Yellow 65AH starting battery. We have made replacement with Winston LP12V 60AH model. The Optimal lead-acid has 28 kg. The Winston lithium battery has 12 kg. In cold weather, you can see the difference in starting the car immediatelly.
Example of discharge of 20Ah cells at 360A (18C)
The graph shows discharge characteristics of 12V batteries using 20Ah cells at 360A.
Building a LiFePO4 battery - charging and initiation
Check a useful article published by one of our customers.
An electric car using the LFP batteries for the traction.
Lithium Battery 12V/180Ah (LFMP12V180AH)
A large capacity 12V battery consisting of 4 cells. A simple solution for a variety of the 12V applications. Ideal for an energy supply in off-grid installations, boats, caravans, etc. It is a completely preinstalled battery.
The initial charge: The battery must be charged to full and each cell needs to be balanced before using.
Download the specification file: GWL-LFMP12V180Ah.pdf
This is a special time-limited offer.
The specification for the 12V LP models of the LiFePO4 batteries
Check the updated version of the specification for the 12V block models of the LP batteries. Download the PDF file here.
FAQ: What is the charging voltage of the 12V battery? 16V or 14.4V?
Question: Some web pages and the GWL blog says that the final voltage of the charge for 12 LP battery is 16V. But some other pages and some charger specifications give information about charging to 14.4 ~ 14.6V. What is the difference?
Answer: The maximal charge voltage for the LiFePO4 technology is 4.00 per cells (16.00V per battery). This is the recommended charge voltage for the initial charging to balance all the cells to the same full level. Check the explanation here.
However for the long term use it may be better not to charger to full, but to charge to a lower voltage to get the maximal life-span. For example charging to 3.65V per cell is considered to be around 85% charge. It works very well for 1000, 2000, 3000 and more cycles. That is why some of the chargers (example the TC-Charger models) charge only to 3.65 V per cell (14.6V per battery). See the additional information at this post.
LP 12V/20A – customer reference – 530 cycles
I am using LiFePO4 batteries for 1.5 year in a cyclic use. The energy drop after 530 cycles is in average about 2 percent. The batteries have always had higher capacity than given by the manufacturer. At this time they still have higher capacity than the nominal value - in average 110%. I am using 12V/20Ah batteries. I have altogether 50 batteries. The weakest of them still has 21 Ah of useable energy. To get ideal performance, it is best to keep the voltage of each cell in between 3.0 to 3.5V. When voltage is dropping bellow 2.8V the battery may become misbalanced and the cells may be damaged.
Harvesting the power of the sun
We have set up a new configuration to test the solar charging of LFP batteries. Two solar panels (217Wp each) are in a serial string to charge a 48V/90Ah battery pack made of 4 pcs of LP12V 90AH batteries.
During a sunny day in October, we are able to gain more than 2 kWh of energy from the 2 panels. (38Ah at 53V = 2kWh)
Our tests have a multiple purpose: to test the solar charging, to examine different solar controllers, to study the charging of the LFP batteries and finally to make a working solution to disconnect from the grid for ever.
If you are interested in these solutions, keep checking our blog or contact us directly.
FAQ: Replacing the SLA batteries
I want to replace the lead acid 12V 100Ah stating battery. Which LFP model can I use?
Answer: The performance of the LFP batteries concerning the starting current is excelling the performance of the SLA (lead-acid) batteries. Our tests and the tests of our customers show that the LP12V 40Ah battery can replace any SLA starting battery (even the 100AH, or 150 Ah models). Even big diesel machines can be started from the LFP battery at very cold weather.
For long term use and massive deployment, we suggest to make testing for each application to make sure that the replacement LFP battery will work properly for long time.
FAQ: battery quality, the new 12V LP models
FAQ: What is the real experience with LiFePO4 batteries?
Answer: The Winston Battery (formerly Thunder Sky) has been producing the LiFePO4 batteries since 2004. The first large volume customers were from the USA. These American customers have been using the LFP batteries from some 5 ~ 6 years with full satisfaction. (Even though there were some problems with the quality of the cells from some of the early production batches.) It is important to note that over the years the technology has been developing. The new LiFeYPO4 technology is much more stable and production quality also continues to grow.
FAQ: I purchased a new LP 12V battery. Why is the battery different from the model I purchased several years ago?
Answer: The original Thunder Sky 12V LP batteries used to have electrochemical balancing (with a floating electrolyte). There were produced from 2007 till spring of 2009. Later versions contained individual cells with mechanical separation. The production of the original LP batteries was stopped in 2009. The news models (40Ah, 60Ah, 90Ah) are produced using individual single cells that are selected in the factory to match the performance and capacity.