Keep and eye on the batteries... when they allow this far of a discharge and go into cell reversal often they are much weaker than the rest of the batteries. I would have the customer cycle them once or twice a week to the 85-90% SOC, just to test how healthy the battery bank is.
To do so, disconnect the AC input to the inverter and let the inverter power some loads until the Magnum says they are 10-15% down... Then reconnect the AC input. I would do this for 4 weeks. After about a month,get them charged up to what you think is full then do a load test, find out what the C/10 discharge rate is and apply that amount of DC current load, you should get that amount of current for at least 5 hours before the voltage drops below 2.0 volt per cell. (50%) state of charge. Measure each battery every 1/2 an hour with a volt meter... battery voltage shouldn't drop near (assuming 12v cells) 12 volts for at least 3.5 to 4 hours. You will need a current meter to monitor the amount of current you're drawing from the battery. Variance can be +/- 10 to 15% depending on the type of loads you place on the battery bank, this is why it's nice to have a linear load tester... Good ones run about $15-20K... My guess is you have a couple of failed, or weak cells, that are aggravating the overall issue. Hope this helps... ________________________________ From: RE-wrenches [re-wrenches-boun...@lists.re-wrenches.org] on behalf of RE Ellison [reelli...@gmail.com] Sent: Friday, December 19, 2014 7:16 AM To: RE-wrenches Subject: Re: [RE-wrenches] Magnum System - Discharged Battery Bank First time I ever saw one of the bank of 80 cells are just about put me in a panic Had no idea they could do that either Bob Ellison Steve Higgins Technical Services Manager P: +1.902.597.4020 M: +1.206.790.5840 F: +1.902.597.8447 Surrette Battery Company Exclusive manufacturer of [cid:rolls7dbc5a]<http://www.rollsbattery.com> On Dec 19, 2014, at 9:48 AM, Corey Shalanski <cshalan...@joule-energy.com<mailto:cshalan...@joule-energy.com>> wrote: Update on my investigation: I visited the customer's house yesterday to set up a pulse charger. Much to my surprise the three batteries that originally registered negative voltage are now reading positive. Does this make sense - are batteries able to shift between negative and positive voltages at such a low charge level? I do not see any evidence of distorted cases. On Thu, Dec 18, 2014 at 7:58 AM, <j...@asis.com<mailto:j...@asis.com>> wrote: I second tump. Most likely a bad /cell battery took out the system. As these are VRLA batteries, I'm curious do,the cases look damaged such as expanded or sunk in? Jay Peltz power _______________________________________________ List sponsored by Redwood Alliance List Address: RE-wrenches@lists.re-wrenches.org<mailto:RE-wrenches@lists.re-wrenches.org> Change listserver email address & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://www.mail-archive.com/re-wrenches@lists.re-wrenches.org/maillist.html List rules & etiquette: www.re-wrenches.org/etiquette.htm<http://www.re-wrenches.org/etiquette.htm> Check out or update participant bios: www.members.re-wrenches.org<http://www.members.re-wrenches.org> This email and its attachments have been scanned by mailWatch E-Mail Firewall for viruses, spam, and malicious content. The information transmitted in this email is intended only for the entity or person to which it is addressed and may contain confidential/privileged material. If you received this in error, please contact the sender and delete the material from any computer. Any review, retransmission, dissemination, or other use of this information by persons or entities other than the intended recipient is strictly prohibited
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