HELP- Solar Generator Charging problems!

[Candela]

Hi there,

I recently built me a solar generator according to the instructions from this YouTube video series:

https://m.youtube.com/playlist?list=...flegLuuvLEyMrU

I slightly modified it, instead I used:

100ah agm deep cycle battery (12v)
200w folding panel (12v)
300 pure sine wave inverter (12v)

Now, everything seems to have been connected correctly, gadgets all turn on/off accordingly, but I am having issues with charging.

When I try to connect my Solar Generator to my solar panels; or Battery tender, both of them cause a quick increase in charging. My battery goes from 12.7 to 13.4 within a minute and when I disconnect it, it drops just as quickly?

Where may the problem be?


Also, at what level will a battery be "considered" topped off; and/ or too low?

[Mike90250]

without watching the questionable video,
When a charge source (solar, grid) is connected to the battery, in order to charge the battery in a reasonable amount of time, higher voltage is used to force power into the battery. When the higher voltage is removed, the battery quickly drops to it's quiescent voltage.

A lead acid battery should be charged to about 14V (read the spec for YOUR battery in CYCLE service). AGM (sealed) batteries have a different spec than flooded batteries, you need to correctly set your charge source for your battery, or you risk ruining your new AGM batteries.

When you replace the batteries, get a pair of 6V golf cart batteries and wire in series, you still get the same storage [ 12V, 200ah ] but avoid the pitfalls of parallel batteries.

[Sunking]

When I try to connect my Solar Generator to my solar panels; or Battery tender, both of them cause a quick increase in charging. My battery goes from 12.7 to 13.4 within a minute and when I disconnect it, it drops just as quickly?

Where may the problem be?

Problem? What problem? The problem is the piece of meat between your ears in need of food or thought. You just do not know what you are doing and have a lot to learn. Assuming the batteries are good it means your batteries are charged up, and your charger is in FLOAT mode. Discharge your battery and that problem goes away. Quit watching You Tube.

Also, at what level will a battery be "considered" topped off; and/ or too low?

A fully charged AGM battery that is disconnected and allow to rest should measure 12.6 to 12.7 volts. All you need to worry about is setting you charge controller Bulk/Absorb voltage to the right voltage somewhere around 14.4 volts, and Float around 13.5 volts. Check you battery manufacture specs.

[Candela]

OK, so its might be all in my head and everything is good!

Yes, I am still a newbie to this solar stuff and yes I have watched some YouTube videos at times, which were very helpful, I have also sat here quietly reading through these forums for 2-3 months.

Thanks to this forum, It has given me a better understanding on Solar, 2 thumbs up!!

I guess I need read thru my charge controllers manual (Morningstar 15amp) and adjust it accordingly.

So, my last questions to you veterans on here, some say to extend my battery life, I should never let it go under 80%, some say you can take it as low as 50%-20% without effecting its life cycle.

How low do you guys take your battery before recharging it, and if 12.7v means is topped off, when will I need to recharge it ?

Thanks in advance for your help

[Sunking]

You design a battery system to only use 20 to 30% of the capacity per day. This means everything has to be designed to do what you intend it to do. 90% of DIY grossly under-size everything. For FLA never go below 50% DOD and for AGM 80% DOD. The deeper you discharge any battery, the fewer cycles.

You charge after every use ASAP. All you need to remember is to keep a PB battery fully charged at all time to maximize cycle life. You have to design the system to replace what you use at night to be fully recharged the next day. The battery is sized to last 2 or 3 days to cover cloudy spells, and the panel wattage must be sized to recover from a deep discharge. Thus is why you need a generator for those cloudy spells or you go dark.

[solardreamer]

Do you no longer recommend "maximum smoke" charging method of setting bulk=absorb=float for solar charging? I had changed charging method based on one of your previous posts and getting better results so just wondering if there is some issue found recently with the charging method. One thing I wonder about is the long term effect of having the higher float charging voltage. Thanks.

...

A fully charged AGM battery that is disconnected and allow to rest should measure 12.6 to 12.7 volts. All you need to worry about is setting you charge controller Bulk/Absorb voltage to the right voltage somewhere around 14.4 volts, and Float around 13.5 volts. Check you battery manufacture specs.

[Sunking]

Do you no longer recommend "maximum smoke" charging method of setting bulk=absorb=float for solar charging?

Yes but there caveats that go with that. If you find in winter months your specific gravity is not getting up to where it should be, then YES raise the voltage up incrementally until you get up to where you want. But as the days become longer, if your panel wattage is sufficient, you should be lowering the voltage. Hopefully by summer you can actually use 3-Stage. If not you know you do not have sufficient panel wattage.

If you look up the major manufactures like Trojan and Rolls they give a range of voltages and applications. For daily solar users, 3-stage algorithm is gone and called a Daily Charge and is a range of 2.4 to 2.5 vpc or 14.4 to 15 volts on a 12 volt battery (6-cells.)

Bottom line is this. You have two choices of undercharged and overcharged with a cycled battery. Only Emergency Stand By Systems use a Float Charge Algorithm can balance on the razors edge. With undercharged you suffer from lower capacity, less cold weather tolerance, and significantly shorter cycle life. With overcharged you benefit full capacity, good cold weather performance, and longer cycle life with respect to under charging. Just do not exceed 2.5 vpc for extended periods of time. If that is not enough, then you know you do not have near enough panel wattage. The tell tale sign of significant over charging is excessive water use and the smell of rotten eggs.