Postby SR » September 3rd, 2018, 3:35 pm
Written by Scottie Johnson owner of xs power batteries
A lot to read, but worth the 10min it will take if you’re undecided on what type of battery to use…
Now that there is likely a more attentive audience, and to help cut down on the incoming messages about the JY competitor’s truck catching fire, I want to offer up some info for those who care to hear it about lithium, AGM and the risks involved in using either. This is in no way to take anything away from JY or any company that makes either product, as we offer both, and still believe there is a place for both.
With regard to using lithium in a car audio build… there are inherent risks any consumer is taking simply by having this product installed in a vehicle (Lipo, LiFePO4, LTO, LMNO, or any other). We make this clear to every customer using our product. Regardless of the charger you use, lithium is volatile by its very nature by comparison to AGM. In the last 11 years since we first started offering lithium options to the public, we have witnessed everything imaginable in both our own R&D, as well as what has happened in the field to us and other companies that we compete against. We have been very fortunate to never have had any fire claims to date (knock on wood) but we are very well aware that at any given time, a simple mistake can be made either in our process, or by the customer to end this streak. Numerous times, we’ve seen a lithium battery that was used and working perfectly the day before just go up in flames for no apparent reason while just sitting all by itself, not connected to anything. So the thought that a lithium battery that is always charged with a lithium charger will never catch fire, is false. It is also very incorrect to believe that as long as you only charge your lithium battery with your alternator that you are also safe. Although an alternator regulator will typically lower it’s voltage once the alternator is warm, it will still provide enough current to send a lithium battery into thermal runaway if it continues to charge the battery once it’s full… especially if the battery was used all day at an event and then connected for the long drive home. A very likely scenario could be that the vehicle is used at an event all day, driven home and parked in the garage, and sometime in the middle of the night, the battery catches fire and takes the car, equipment, and entire house down with it. If the vehicle is placed on charge at the time, the chances are far more likely, especially if the wrong charger type is used.
In this particular situation, it was stated that the vehicle caught fire during a demo, which would indicate that the charger used was not the immediate reason for this type of failure. It is possible that the customer could have used his AGM charger and always turned it off once it reached the float stage, which would be no different than using a lithium type battery charger. It is also possible that the AGM type charger was used, and nothing was ever actually damaged in the battery and this incident was unrelated to the charger used at all. On several occasions, I have seen audio lithium companies say that you can use any charger you want, and charging with your alt is fine too, which is false. At the same time, it is also possible that by using the wrong type charger, a cell was damaged, which lead to a failure that resulted in the fire. In situations like this, it is impossible to know for sure, but it is important to be aware that even if you use the correct charger, that this could still happen. Lithium is much more energy dense than AGM, so if there is an internal failure in an installation like this, all of the energy that is connected to the failure point will dump into that single point, which causes a bad situation to become much worse.
By comparison, I’m sure many have seen what happens to an AGM battery that has either reached the end of its life and no longer accepts charge, or is overcharged, or exposed to extreme heat and relative high charge voltage simultaneously. The battery will overheat, which causes the plastic housing to soften, and the pressure builds inside. As the pressure builds, the battery will begin to swell and eventually if the charge is not stopped, the case will crack and relieve the pressure. All in all, it’s a pretty uneventful situation… just a little smelly. In my 25 years of experience with AGM batteries, I have never seen an AGM battery actually “explode” although they may look like they have from the swelling. The only way this would happen would be if they were mounted in a completely sealed chamber and gasses expelled as they were in thermal runaway are somehow ignited, then the gas would be what explodes, not the actual battery. Flooded, or wet cell lead acid batteries are very different from AGM. Since they are not sealed, they generate gas by design. It is never recommended to use wet cell batteries inside a confined area, especially in the passenger compartment. During charge, it is very possible that a flooded battery could ignite internally on its own or from a nearby source like an amplifier, subwoofer, etc. When this happens, there is an actual explosion, that can cause damage to anything within an 8’ radius depending on the size of battery/battery bank. This is likely the most common cause of automotive, boat, and golf cart fires in general.
Regardless of the type of battery product, it is always possible for there to be a problem with the wiring, which could cause a fire all on its own simply from the extreme amount of energy storage in the vehicle. The easy part is educating yourself to minimize the risk. So, as a consumer, how do you best protect yourself from having something like this happen? The first step is to be aware of the risks. 1.) Knowing what not to do is half the battle. 2.) Stop buying inexpensive, or home-made products from small time builders. There are certain processes that must be followed when building lithium batteries that a guy in his garage at home is not likely to know. If you’re lucky, you’ll get by with a battery that just doesn’t work after a couple of years. If you’re unlucky, you could lose your car, house and everything in it. 3.) In a lithium installation, install them in a way that you can get them out quickly in an emergency. 4.) Use the proper charger for the application, and stop charging once the batteries are full (this includes from the alternator). 5.) Pay attention! If your batteries are getting hot to touch, let them cool down. Watch your voltage/capacity. If you are constantly completely draining your battery/bank, it is going to fail or at the very least, it won’t last as long as it should. Don’t let your battery/bank rest in a low state of charge. It’s not good for either type, and specifically with lithium, if you fully discharge a lithium battery and try to charge it with more than 1-2A of current, you are likely to cause immediate damage to it. 6.) Don’t combine AGM with LiFePO4 batteries. We’ve been saying this from the very beginning. Just in the short time you let the bank sit overnight, the difference in resting voltage from one chemistry to another will drain the lithium to less than 50% state of charge, and that’s assuming the AGM is fully charged. This is why your alternator hates life when you first start the vehicle up with an AGM/LiFePO4 combo setup. The lithium is sucking up all the current it can from the alternator, which builds heat internally, and uses up the cycle life of the battery. Better quality lithium batteries will deal with this better than cheap ones, but they will all suffer from it, no matter how well they are built.
As long as some common sense and a decent amount of precaution is taken, you should be fine, but even then, accidents or unexpected failures can happen. XS Power will continue to offer AGM, Lithium, and Ultra Capacitors, and even plan to release some other new tech soon. Hopefully some good comes out of this situation and some of the carelessness I’ve seen recently gets cleaned up so nobody gets seriously hurt or injured. We can’t keep accidents from happening, but by being a little more responsible, we sure can prevent a lot of bad situations from becoming reality…….
