Charging batteries with Outback

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My RE system: Flexpower Two: (2) FXR3048A, (2) FM80, MATE3s, FlexNetDC
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Charging batteries with Outback

Post by raysun » Thu Jan 02, 2020 2:16 pm

Inadvertently ran an interesting demonstration in battery charging yesterday.

Our battery is fully charged daily as we generally use 50% of capacity between sunset and sunrise. The system is pretty well configured, and Bulk proceeds to 85% SOC, then Absorb takes over for 2 hours, taking the battery to 100% SOC, wherein Float is maintained until sunset.

Last evening, with the battery at 80% SOC, and my wife's Christmas lights blazing away to increase average consumption nearly 6 fold, I ran the generator a bit to put more charge on the battery. We were leaving early in the morning and I didn't want to risk too low an SOC causing a system shutdown prior to solar charging coming up to strength in the morning.

The inverter charger did its typical Bulk until about 92%, then switched to Float. I allowed it to Float until about 95% SOC.

Notice that Absorb was skipped. This due to the fact the battery had not dropped below the REBULK voltage, so no time was added to the Absorb timer.

This morning, the battery was again at 80% SOC and the FM80s ran their normal charge routine. At 85% SOC, the Absorb cycle executed for 2 hours until charge parameters were met, and system switched to Float.

The difference is the battery had dropped below REBULK voltage to sufficiently add time to the Absorb timer.

It's nice to see equipment working as designed!
Last edited by raysun on Thu Jan 02, 2020 2:36 pm, edited 1 time in total.

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Gwendoly Espe
Applications Engineering
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Joined: Wed Feb 22, 2017 10:04 am

Re: Charging batteries with Outback

Post by Gwendoly Espe » Thu Jan 02, 2020 2:29 pm

Thanks for sharing! \:D/
Gwendoly Espe
Applications Engineer

Alpha Technologies Inc. / OutBack Power Technologies
3767 Alpha Way Bellingham WA 98226 USA

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