Battery Evo, Big Battery and Tech Direct Club are all one and the same. Buyer beware. Recently I had a customer purchase a 120ah 48v ( 24v units in series). These supposedly have new A123 LFP cells in them with a 10 year warranty. These batteries were a close match in size and output to the existing batteries at a far lower price, which was important for my customer's budget. The batteries arrived quick enough and I welded together a pair of wall mounts for a clean install as well as built some independent switching along with a new pair of bus bars to handle the increased amperage.
The batteries were about 2 volts different when I turned them on so I brought the lower voltage battery up to equal the second one. Then I made sure the existing batteries in the system were at the same voltage and set the charge parameters on the inverter to be within the voltage range of all of batteries which they all had the same LFP chemistry and capacity anyway.
Things were clipping along nicely until 4:am the next morning when the Evo batteries fell off a cliff and shut down. I went to the site and started testing the equipment. The two Evo batteries showed a two volt difference in the built in display. Both showed above a minimum shutdown level though. One at 24.6v and the other at 26.5v. I proceeded to attempt to charge the lower battery again with two separate 24v chargers to no avail. The display would just shut down. I called and got through to Fred at tech support at their Washington state number. He proceeded to through some softball questions at me finally indicating that I needed to send the unit back since it wouldn't accept a charge while insinuating that there was something wrong with both of the chargers that I had tried to use. During our conversation he directed me to take the cover of and try to reinitiate the BMS by removing and reconnecting the leads. The battery re-initiated so I went on to attempt charging again after ending the call with tech support. As I hooked up the 24v charger again the BMS shut down. Wanting to get to the bottom of this I decided to do a cell check. Remember, these are purportedly brand new A123 cell packs. The results were as follows:
1. 2.627
2. 3.175
3. 3.188
4. 3.181
5. 3.161
6. 3.181
7. 3.172
8. 3.172
The obvious culprit was of course cell pack 1. I called Fred back and informed him of my findings. He told me to use the form on the Battery Evo website and get an RMA. A new battery would be sent out immediately. After a number of tries by both me and my customer to get in contact with Battery Evo a replacement was sent out along with a return shipping label for the original battery. Unfortunately, it was a battery of, as I came to find out later, lesser capacity because they were more degraded used cells. The replacement battery was of the same size and shape, it just had a multi color case instead of the black case. I called Fred again and got John on the line and told him about the battery I got that looked like it was assembled from spare parts. Eventually Fred got on the line and I asked him if I could take the replacement battery out of the multi color case and put it in the original defective battery case. He agreed that that was a good idea rather than send back a second battery.He did not indicate at that time that the cells were of lesser quality in the replacement pack.
While I was on the phone with Fred this time we were also having a discussion as to how to get the second original battery to accept a charge as it was 2 volts lower than the replacement battery. Fred had me take the cover off of that battery and jump across the BMS to activate it. Which worked. Unfortunately when I connected the 24v charge to that battery it shut down again as well. I decided to test the cells to get a better picture. So, the second original battery with purportedly brand new A123 cell packs tested as follows:
1. 3.013
2. 3.655
3. 3.156
4. 3.167
5. 3.161
6. 3.151
7. 3.122
8. 3.143
It was obvious that the #2 high voltage was causing the shutdown.
At this point I was starting to think that maybe there was some deception going on. I made that case changeover on the original battery #1 and it's replacement and made the following discovery as shown in the attached images of the cells
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These two images are of the original battery #1 and its replacement
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So it became obvious that Battery Evo, Big Battery or Tech Direct Club intentionally sent out batteries that were not what they advertised them to be. This is an ongoing experience. As of today, after requesting a refund and getting the run around I'm not sure what direction I will take. Unfortunately it won't be pleasant from this point on.
Don't get me wrong, I am 100% in favor of upcycling and reusing lithium batteries that are fully tested. I have successfully purchased and used batteries from Battery Hookup, EV West and others with excellent results. The difference was that they are up front about what they are selling and conduct real testing on their products.