TME - Tejera Microsystems Engineering — The Xtrema Charger - ripoff, junk
More than a year ago, I needed to buy a powerful lithium battery charger. I looked around the web and found this Xtrema product which claimed to output the highest power of them all. The maker also claimed to give post-purchase technical support by issuing new firmware versions. I had quite high expectations of this product.
I knew that it would come without the ability to use mains voltage right away, so I bought a power supply locally. This was a part of the deal, even though competing products already come with a wall plug as standard.
Then the real problems started. I discovered that this product's firmware is perhaps as botched as the first edition of Windows 95! The first thing that will probably annoy you is a certain probability that an error will appear the moment you try to start the charging. Sometimes you have to try to start it several times until it finally keeps running. It is a software problem - I have checked with different batteries, measured voltages and everything is connected properly. Nothing is corroded.
The same error BAL_ERR_03 can also randomly pop up during the charging cycle, there is about 5% chance that the cycle will be interrupted, forcing you to go and check if it's still running. The voltages are good as checked by me and when restarted, it usually runs well to the finish.
Then the capacity indicator. It suffers from an overflow error and won't show capacities correctly when it exceeds 9999mAh. It starts counting from zero, then it starts displaying gibberish.
The charger says that it has a protection against charging deeply discharged batteries. When a cell is below 3V, the charging won't start. I, however, often run into situations where one of the cells has about 2.7V and while this is not too bad and won't damage the battery, the charger will still refuse to operate and I have to connect it to an E-flite charger to get it past the limiting voltage and only then will Xtrema be vouchsafed to work.
The hardware of the charger is not perfect either. When operated at its maximum rated current, it will emit odor. I believe that the silicone insulating pads between the transistors and the case produce the smell.
The firmware update is useless. In a year and half, NOTHING was issued to fix the problems. The beta they have posted on the website gives the BAL_ERR_03 even more often, so I had to revert to the previous version.
I have brought up all these points and more to the staff of TME, but they either didn't respond at all, or they sent back a random snippet of the manual that didn't help at all.
Their product is JUNK and their technical support is USELESS! The charger that is sold for $177 as a "SALE" price is actually worth $40 as a competitive price. I will not do business with this company anymore and will prefer China-made chargers. They are of better value and don't have ridiculous flaws. A $55 Chinese charger comes with both car battery and mains power input, has a full-aluminum blued body, the functions are also selected using a big display and it is RELIABLE.
TME, grow some spine and stop making your country ashamed!