Navitron Renewable Energy and Sustainability Forum

Energy/Electricity Storage and Use/Grid Connection => Off-Grid, Batteries & Inverters => Topic started by: sierrawhiskey on June 19, 2018, 10:58:02 PM



Title: Small Starter Solar Garage Project Questions
Post by: sierrawhiskey on June 19, 2018, 10:58:02 PM
Hi Everyone,

I've currently have this lot connected for the last 2-3 months.

Solar Charge Controller = Qaurora Tracer MPPT 10A
Solar Panel = 10W 12v Energy+ Poly Solar Panel
Battery = BMW AGM 12v 90Ah

i don't have anything connected to the battery yet, still looking for an inverter cheap enough.

Everyday it says my battery is 14.2 charged and over night it drops to 12 or below when its had no load on the battery?

Could someone explain why this is and how to fix it please

Thanks



Title: Re: Small Starter Solar Garage Project Questions
Post by: oliver90owner on June 20, 2018, 06:41:36 AM
Perfectly normal.  You won’t ”fix” it.  Do note the smile on the screen.

It is a 12V battery, not a 14V version.  Any battery requires a higher voltage to enable a current through it to charge it.  The voltages you are reporting are typical.  Automotive systems work on 14.4V regulation from the alternator.

Your ten Watt panel is just about large enough to keep your battery reasonably well charged but it is likely insufficient to actually charge the battery.  A 40W panel would be far better.


Title: Re: Small Starter Solar Garage Project Questions
Post by: linesrg on June 20, 2018, 07:41:01 AM
sierra whiskey,

You don't say what state or age the battery is. If it is used then it may well be partially dried out/ sulphated.

As oliver90owner has observed the PV panel you have isn't really adequate.

Regards

Richard