GT500 sees battery as DC Supply - RC Groups
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Aug 10, 2017, 12:42 AM
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GT500 sees battery as DC Supply


I have a 24V SLA battery bank that I occasionally use with my GT500. I use the regenerative discharge feature to put my LiPos into storage charge, and put that energy into the SLA batteries. It typically works as expected. But occasionally, if I discharge a second batch of batteries, the GT500 will run for a minute then display an error message saying it detects a DC supply present and will not allow regen discharge. To get past this error message, I need to select a different supply without regen discharge, and discharge my lipos into the resistive load. Why would the GT500 see the battery as a DC supply?
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Aug 10, 2017, 07:56 PM
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The GT500 senses a DC supply if the input voltage rises above a certain threshold during the time when the regenerative amps is low.

Could you pls post your charger settings as well as specs of your SLA battery bank? If we are able to replicate the symptoms, perhaps we can fine tune the code to get the correct behaviour.
Aug 10, 2017, 08:43 PM
Registered User
Thanks for the reply. I'm including a photo of my current battery settings. I've tried adjusting these settings to overcome the DC supply error message, with no success. The batteries I'm using are Enersys Cyclon "E" cells, VRLA batteries. The are 2.0v 8.0Ah cells in series. The application sheet for these cells can be found here.

http://www.enersys.com/WorkArea/Down...et.aspx?id=491
Aug 11, 2017, 06:44 AM
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Thanks for the link.

May I know the total discharge amps as well and if you are discharging from 1s packs?
Aug 11, 2017, 04:00 PM
Registered User
I am typically discharging various 3S packs into the SLA battery. My discharge rate would depend on the battery, typically a 1C discharge, and would be between 1A and 2.2A. I haven't used this feature a lot, I don't recall if I have parallel discharged any batteries. If so, the peak discharge current would have been 8.8A.
Aug 12, 2017, 01:56 AM
Registered User
Thanks, we'll look into it.

Meanwhile, if you haven't already done so, I suggest checking the connections to make sure they are tight and both input and output cables are in good condition. If you have another SLA supply battery, it would also help to see if the spare SLA pack produces the same symptoms.
Aug 17, 2017, 07:31 AM
Registered User
Hi trimmkm,
I have not been able to reproduce the symptoms of the error message. I'll probably need more info from you to proceed. Could you email me at fong@revolectrix.com to discuss?
Aug 22, 2017, 06:47 PM
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Thomas Cummings's Avatar

Forgive off topic but relevant question...


I am using a Bump Controller and a Dual Powerlab 8x2 and attempting to use the regenerative discharge mode.

My power supply consists of four (4) 12V lead acid deep cycle batteries.

What is the appropriate "Regen Max Limit" (Voltage) setting? Is it 14.4V or would it be 4x14.4V?

I believe that the Supply Low Limit setting is multiplied by the detected number of deep cycle batteries, and I am wondering if this setting is multiplied as well?

Thanks in advance for the help!
Aug 24, 2017, 12:32 PM
Registered User
Quote:
Originally Posted by Thomas Cummings
I am using a Bump Controller and a Dual Powerlab 8x2 and attempting to use the regenerative discharge mode.

My power supply consists of four (4) 12V lead acid deep cycle batteries.

What is the appropriate "Regen Max Limit" (Voltage) setting? Is it 14.4V or would it be 4x14.4V?

I believe that the Supply Low Limit setting is multiplied by the detected number of deep cycle batteries, and I am wondering if this setting is multiplied as well?

Thanks in advance for the help!
Yes, the Regen Max Limit will also be multiplied by the detected supply voltage 12/24/36/48v.
However, I'm not certain the Dual PL8x2 will allow the full 4x14.4v termination voltage - that *may* exceed to overall max input voltage which is safe for the charger ... it's possibly that it may terminate regen charging at a slightly lower voltage .... 4x14.4v=57.6v which is significantly higher than the max rated input voltage of 52v.
I'll check with our PowerLab engineer to see if there are other internal max volts limits that take affect.
Aug 24, 2017, 01:52 PM
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Thomas Cummings's Avatar
Kelly,

As always, a big THANK YOU for all you do for us here!

Thomas


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