Paul Buff
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 p.2 #9 · Vagabond II reliability | |
willowsr wrote:
Could we return to the issue of the reliability of recently shipped (last 4 to 8 weeks) Vagabond II units? Clearly, we have people reading this thread who are knowledgeable and whose information base goes well beyond the scope of a single (somewhat frustrated) user. Are there any thoughts on the reliability of comparable competing (Tronix XT, BatPac or other?) units? Regards to all, and thanks for their contributions.
Yes . . .we should have never gotten so far off topic.
We have many thousand Vag 2s in the field with a very good reliability record. The most common issue is sulfated batteries. If they are deep discharged they can be rendered useless if not recharged right away. If a battery is badly sulfated, the charger can keep trying to charge it. Because there is no temperature sensing between the charger and the battery, the charger can keep pumping current into the battery and cause heating. This is true of all SLA batteries and chargers that are not thermally connected.
But the bigger issue has occurred quite recently (in the past three months or so) and seems to stem from the most recent batch of inverters we received. We test the daylights out of these several times before they are shipped, running them unmercifully on a 2500WS Zeus pack and recharging them before shipment.
But, rather suddenly, we began to see about 4-5% of units fail prematurely in the field, in some cases on the very first use - often on a single low power light. The typical report is similar to what you see here . . . the fuse blows and/or the units smokes or refuses to operate. We are doing everything we can to identify exactly what is failing and why, as has the vendor. We believe it to be Mosfets failing from transient voltages - possibly a defective batch of Mosfets and possibly a change the vendor made without our knowledge. I have been extremely aggressive with the vendor and with our tech staff.
Of course, when this happens we do everything possible to work with the customer to rectify the issue, and I always try to put myself in the customers shoes . . . .meaning I can't blame a customer for being very upset when this happens. And, even though I am not physically in the plant overseeing the tech staff, I have been all over them on this issue and, much more so, extremely aggressive with the vendor.
It t's my understanding that we received a small number of inverters a couple of days ago with modifications intended to correct the excess failure rate and that Joe (chief technician for many years) has done everything possible to try to destroy them but has not been able to induce any failures whatsoever. I have been in contact with the vendor at least a dozen times in the past few weeks, as have my Chief Engineer and my manufacturing VP, expressing the immediate need to find and correct the issue as immediately as humanly possible. The vendor completely tests each inverter before they are shipped to us and, as I said, we test and stress each one very thoroughly before they are shipped, and neither us nor the vendor has been able to induce the type of failure reported here.
It is important to note that 95% of V2s shipped work without any issue whatsoever, other than occasional sulfated batteries. But prior to the latest batch, that number was more like 99%.
When I first started seeing reports of these failures about 90 days ago, I set to work very intensely developing the Mini Lithium, using a different, very reliable vendor (the same vendor that makes Samlex inverters) and working with six highly respected battery vendors. The battery vendor I settled on has been extremely instrumental in helping me choose and design the Lithium battery and the protection circuitry that is integral to the battery pack.
Unlike SLA batteries, the Lithium battery has on-board temperature sensing, over charge and over discharge protection, cannot sulfate and can be left in the discharged state for months without any damage whatsoever. I have torture-tested the battery/inverter combination personally, continuously firing one or two ABs or Einsteins once per ten seconds until the battery is exhausted, without seeing any temperature at the battery above 105°F. If the firing rate is increased considerably, the inverter will eventually sense over heating and shut down, then resume after a cooling period.
I wish I could say these people are nuts and there is no issue, but my conscience always demands that I tell everything I no . . the good, bad and ugly.
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