Hi Wrenches, I wanted to follow up on my results, as it relates to some current threads on Boot-strapping discharged Lithium batteries.
This off-grid project had 3 x 20 kW 48V stacks of Lithium batteries, made by GSL Energy. They sat in an abandoned construction site for 18 months powered off, discharged, through a winter down to -40. At least 3 electricians had worked on this job previously & gave up. The Sol-Ark 15K inverter was installed, but poorly. Everything was dead no power, and no generator pass-through. I temporarily re-wired the generator feed to the load panel as there was no transfer switch installed. The Champion 8.5 kW gen is a poor choice for this system but that's another topic. I warmed it up, gave it an overdue oil change, as it was going to get some use in the coming days. The building had been heated for the last couple weeks and everything was well above freezing. Opening up the stacks found 4 x 12V 400 Ah Lithium batteries, with an external BMS system but no BMS on the individual batteries. Each 12V battery measured around 2V. I disconnected the buss bars and using a 30V 30A power supply set to 27V & charged the 12V batteries in pairs for 30 minutes each. Monitored temperature - didn't rise. They held voltage after that charge. Removed the 30V charger, reconnected buss bars, and wired in a DLS 45/13 power supply and repeated process on the other stacks. Let them charge up for 12 hrs. The BMS powered on. Voltage was now 53V, but the BMS refused to engage the final contactor labelled K3. The display on the battery was showing the SOC at 0%, 0A in, but voltage correct. I surmised that K3 contactor was SOC controlled. I re-wired the DLS chargers so that the CT's would register input current and kept charging. No change. I was able to WhatsApp message, through an interpreter, to support @ GSL Energy with their +16hr time zone. They weren't much help, but gave me some clues. Through trial and error by reprogramming batteries as individual stacks and disconnecting the CANbus cables, got each battery to fully power up and engage K3 contactor. The CAN combiner box was improperly wired. Remedied that, and was able to get the three stacks all working together. Removed the DLS chargers, re-wired the generator input, powered up the Sol Ark 15K and it was behaving oddly. Would power up OK but no AC output unless the generator was run briefly. Finally got it to fully power up, left the system on overnight. Next morning, the K3 contactors opened and system was off. Reset the batteries and re-powered, but no AC output from the Sol Ark. I found the WiFi Dongle and got that online via Starlink. Got Sol Ark tech support on the phone & they got right at it. Impressed. They did a firmware update, factory reset, and reprogram since we just didn't know the history. They also advised the GSL Energy batteries were not data compatible, so disconnected the CAN port to run the batteries open loop. The system then operated properly. Let the generator charge via Sol Ark until all batteries at 100%. Left lots of lights on overnight, batteries were at 80% SOC in the morning, power still on. Put a 4 kW load on the system and battery voltage held. Charged back up with PV that I wired in while waiting for batteries to charge. The batteries appear fine. Time will tell. I hear that Lithium batteries can't tolerate freezing. If this was a FLA or AGM bank at near 0V in -40 they would have frozen, split open, caused a mess, and be destroyed. I'd sure not recommend anyone abusing batteries like this, but it seems Lithium is more tolerant than initially thought. Kevin From: RE-wrenches <re-wrenches-boun...@lists.re-wrenches.org> On Behalf Of White, Will via RE-wrenches Sent: Monday, November 25, 2024 10:16 AM To: RE-wrenches <re-wrenches@lists.re-wrenches.org> Cc: White, Will <will.wh...@fluke.com> Subject: Re: [RE-wrenches] [EXTERNAL] Frozen LPF batteries - damaged or salvageable? My understanding is that if lithium-ion batteries freeze, they're destroyed with no hope of recovery. Like Jay said, I'd call the battery manufacturer and ask them. Let us know what they say. Thanks, Will ________________________________ From: RE-wrenches <re-wrenches-boun...@lists.re-wrenches.org<mailto:re-wrenches-boun...@lists.re-wrenches.org>> on behalf of Kevin Pegg via RE-wrenches <re-wrenches@lists.re-wrenches.org<mailto:re-wrenches@lists.re-wrenches.org>> Sent: Friday, November 22, 2024 12:54 PM To: re-wrenches@lists.re-wrenches.org<mailto:re-wrenches@lists.re-wrenches.org> <re-wrenches@lists.re-wrenches.org<mailto:re-wrenches@lists.re-wrenches.org>> Cc: Kevin Pegg <kp...@energyalternatives.ca<mailto:kp...@energyalternatives.ca>> Subject: [EXTERNAL] [RE-wrenches] Frozen LPF batteries - damaged or salvageable? CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe. Hi Wrenches, I've been asked to take on a project that was abandoned for 16 months. It has 3 stacks of 400Ah 51.2V Lithium batteries (gsl-energy) tied to a Sol-Ark. It was running at one point spring of 2023 with generator charging but has been offline dark for over a year. PV is still in crates. The batteries sat in an unheated unfinished building winter 23/24 and it would have got down to -40C (-40F) for weeks during winter cold snaps. The BMS did not power on, did not spend time troubleshooting during the initial assessment as I wanted to learn more. The battery specs say storage no colder than 0c (32F) and operation no colder than -20c (-4F). What I am trying to determine is if those batteries are salvageable, or damaged and if we should just replace them with new. I am also tempted to replace the sol-ark, haven't worked with that brand before but am not impressed with what I have heard from other people's experiences. Kevin Pegg EA Energy Alternatives Ltd. 37471 Hwy 16 E Telkwa, BC V0J 2X2 ________________________________ Please be advised that this email may contain confidential information. If you are not the intended recipient, please notify us by email by replying to the sender and delete this message.
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