June 4, 20233 yr Hi all, You know what to do when you switch on the battery and hear a poof and smell smoke right? Just switch off and press the Undo button. Yeah right, I wish. I connected a Giter "48V" lithium battery to a Full Circle Solar 5kw. It's been working for months on lead acid. I switched on using the DC breaker and then heard a clicking/sparking sound (not relay) and the inverter display is blank and switches on and off rapidly in a loop. After the initial WTF moment I started looking at numbers and saw this... Measured Battery Voltage 53.5V DC input 48V DC charger output 54V The battery is nominal 48V and operates to 57.6V. I think it must be a 16 cell and not the usual 15 cell. Is it possible that the voltage is too high for the inverter or was it inrush current or something else that killed it? All I can see are some low voltage caps 16V being bulged around the 7912 (-12V) regulator. Could the damage be limited to this or should I look further? Am I wasting time trying to repair it? Any advice will be highly appreciated.
June 5, 20233 yr 28 minutes ago, PsyWulf said: You skipped the Capacitor precharge when changing to Lithium Yes. Some battery BMSs limit the current on start-up; some just disconnect on overload. It sounds like yours is the latter. Hence the twitching at the start. This twitching isn't good for the inverter, but you may well have gotten away with it. 6 hours ago, RudShep said: The battery is nominal 48V and operates to 57.6V. I think it must be a 16 cell and not the usual 15 cell. Is it possible that the voltage is too high for the inverter or was it inrush current or something else that killed it? Anything less than at least 60.0 V, and with many models, about 66 V, is most unlikely to be the problem. If you pre-charge, you'll possibly find that it works just fine. 6 hours ago, RudShep said: All I can see are some low voltage caps 16V being bulged around the 7912 (-12V) regulator. That's unfortunately common. You might as well replace some capacitors around that area while you have it open as a precaution. I recently had one of my inverters fail due to dried out capacitors, and it ended up twitching for hours when I wasn't home. That ended up damaging the solar charge controller. Recapping the power supply fixed the twitching.
June 5, 20233 yr 3 hours ago, PsyWulf said: You skipped the Capacitor precharge when changing to Lithium Not to mention that you can also damage or shorten the lifecycle of the inverters capacitor bank.
June 5, 20233 yr 1 hour ago, BritishRacingGreen said: you can also damage or shorten the lifecycle of the inverters capacitor bank. And these capacitors protect the MOSFETs from blowing up.
June 5, 20233 yr What I use is an cars old ballast resister connected on series screwed together back to back works great to charge those caps slowly and these resisters are cheap and can be bought at your local car dealers .
June 5, 20233 yr 1 hour ago, GMAC said: What I use is an cars old ballast resister connected on series screwed together back to back works great to charge those caps slowly and these resisters are cheap and can be bought at your local car dealers . At less than 3 ohm IIRC there is still quite some current flowing through this kind of resistor. I prefer something around the 22 ohm value.
June 6, 20233 yr On 2023/06/04 at 9:35 PM, RudShep said: Hi all, You know what to do when you switch on the battery and hear a poof and smell smoke right? Just switch off and press the Undo button. Yeah right, I wish. I connected a Giter "48V" lithium battery to a Full Circle Solar 5kw. It's been working for months on lead acid. I switched on using the DC breaker and then heard a clicking/sparking sound (not relay) and the inverter display is blank and switches on and off rapidly in a loop. After the initial WTF moment I started looking at numbers and saw this... Measured Battery Voltage 53.5V DC input 48V DC charger output 54V The battery is nominal 48V and operates to 57.6V. I think it must be a 16 cell and not the usual 15 cell. Is it possible that the voltage is too high for the inverter or was it inrush current or something else that killed it? All I can see are some low voltage caps 16V being bulged around the 7912 (-12V) regulator. Could the damage be limited to this or should I look further? Am I wasting time trying to repair it? Any advice will be highly appreciated. Hi @RudShep whats your progress on this failure. You mentioned smoke, is that IGBTs failure? Edited June 6, 20233 yr by BritishRacingGreen
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