Need opinions on a portable solar battery system

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Xanavi

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Mar 24, 2021
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Milwaukee

Sun Power 50w 17.6v 2.8a direct into a TalentCell 6.8ah LiFePo4 battery with a low/high voltage cutoff circuit.


This would be for running a few fans and a small PWM heater for astronomy dew control at night.

My charging day will be usually very sunny but I would also run a 9v 0.5a fan from the 9v port.


Do you see any obvious problems with a setup like this?
 

Gary RV_Wizard

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Feb 2, 2005
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At our Silver Springs FL home
Obviously the solar panel isn't going to help at night or do much of anything except at high noon, so the question is whether the 6.5 amp-hours of battery is enough for your needs. You said nothing about actual power consumption (amps or watts for that heater and fans), so we can't even guess. Three hours use at 2 amps will drain that little battery until it recharges the next sunny day. You need to get more data on the amount of power you will expend between charge-days.
 

Xanavi

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Mar 24, 2021
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Milwaukee
The power usage is fine. Less than an amp for 6 hours max. Mostly concerned if the battery would be fully charged over the day, and if it's safe sitting there full with solar connected.

I heard hese sunflower panels with copper backplane hit full voltage with only minor sunlight, that would still charge this slowly correct?
 
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Frank B

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Apr 23, 2005
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Calgary, Alberta
The power usage is fine. Less than an amp for 6 hours max. Mostly concerned if the battery would be fully charged over the day, and if it's safe sitting there full with solar connected.

I heard hese sunflower panels with copper backplane hit full voltage with only minor sunlight, that would still charge this slowly correct?
From the specs provided on that Amazon link for the battery:

Over-charge protection, over-discharge protection, short-circuit protection.

However, this is for the supplied charger. I don't know what the specs for the charger are.

A solar panel has a rated open circuit voltage, that is, the maximum voltage it can put out when in the sun with nothing connected to it. As soon as you connect something, however, that voltage goes down. One can short out a solar panel without damaging it. The voltage just goes to near-zero. In between those two extremes, the panel will output as much power as it can, and the voltage will vary between its maximum and minimum.

I don't know if there is enough information there for any of us to give you a yes or a no on what you plan to do.
 
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