Battery Levels Belo 50 percent

[Neilthurston99]

Hello

I am an absolute newbie to solar energy.

I am using lead acid batteries which I understand should not be run on less than 50 percent of charge to avoid damage to the batteries.

I am setting up a solar powered system remotely and will probably visit around once per week.

I have bought a 1000w Renogy Inverter and yet to buy a battery shunt / monitor system.

Any guidance on how I can set up my system so battery charge levels do not fall below 50 percent would be much appreciated.

Cheers

Neil

 

[BryceFreeman]

All-in-one inverter charger can do it as most of them can set the cut off point of discharging. You can set the minimun soc to 50 percent to avoid damage to the batteries. Since you have bought a 1000w Renogy Inverter, you may consider a mppt charge controller with this feature.

 

[chrisski]

Shut the inverter off when not in use. It probably has a 10 watt idle draw and will draw 250 watt hours a day. On a smaller system with just one 100 ah battery, that's 1/4 your usable production. If you go away and you come back after a cloudy week, this could drain the battery.

Other than that, figure out the electricity you want to use in watt hours, and use a solar calculator like in my signature block to determine how many panels to get.

Lead acid batteries top out at a 10% - 30% charge rate, more like towards the 10, so your solar charge controller should not exceed that limit. some are adjustable, others will put out to a max advertised. That is about 150 watts of panels per 100 AH of battery pack. So in addition to sizing a lead acid battery bank for watt hours, you also have to size it to be charged no higher than this max rate.

Since you already have an inverter, I would not get an all in one. I also don't like all in ones because they tend to have higher idle draw.

If you wanted to, you coudl get a battery shunt with a programmable relay to automatically shut off the inverter.

 

[Zwy]

Hello

I am an absolute newbie to solar energy.

I am using lead acid batteries which I understand should not be run on less than 50 percent of charge to avoid damage to the batteries.

I am setting up a solar powered system remotely and will probably visit around once per week.

I have bought a 1000w Renogy Inverter and yet to buy a battery shunt / monitor system.

Any guidance on how I can set up my system so battery charge levels do not fall below 50 percent would be much appreciated.

Cheers

Neil

You also need to get to 100% SOC on a very regular basis to avoid damage to the batteries. If the 100% SOC thru absorption is not reached, sulfation on the plates will lead to an early death, possibly less than 1 year.

That is the major problem with lead acid batteries on a solar system. Absorption charge takes time, as the lead acid battery nears 100% SOC, the internal resistance increases and the charge rate lessens. The problem is solar input is only during daylight hours so time is limited which is opposite what your batteries need.

It can be done but requires basically a split bank where one half is in use while the other is being absorption charged to 100% SOC with a charger. This does require a much larger PV system and a large lead acid bank. Keeping the bank being used above 50% can be difficult.

Given the price of LFP cheap batteries today, you would do better to use the lead acid as a reserve when there are several days of limited PV production while using the LFP for the majority of needs. You don't state what your system specs are and how it is used. It could be your needs might be met with lead acid but most likely you aren't reaching 100% SOC and killing the batteries.

 

[mikefitz]

Hi Neal, in the UK quality lead acid batteries are expensive, all the low cost lead batteries on the market will not last long in a solar charged system with an inverter. Consider Fogstar lithium batteries , at £370 for 105Ah,

Lithium Leisure Battery - Fogstar Drift 12v 105Ah

105ah 12v Fogstar Drift Lithium Leisure Battery | Grade A LiFePO4 cells, JBD BMS, Bluetooth, Heating | Lowest Prices in the UK. 10 Year Warranty.

www.fogstar.co.uk

Compared to a quality lead battery, at £ 245

Victron 110Ah AGM Dual Purpose 12V - Deep Cycle Battery | Climbingvan

The Victron 12V 110Ah AGM Dual Purpose Leisure Battery is a VRLA (Valve Regulated Lead Acid) battery.. They are a deep cycle AGM battery, with excellent high current performance. This makes them suitable both as a leisure battery, and as a starter battery. 110Ah capacity Suitable for 12V...

climbingvan.co.uk

Perhaps more details of your proposed setup would help, what is electrical load?

 

[Neilthurston99]

Hello

I am an absolute newbie to solar energy.

I am using lead acid batteries which I understand should not be run on less than 50 percent of charge to avoid damage to the batteries.

I am setting up a solar powered system remotely and will probably visit around once per week.

I have bought a 1000w Renogy Inverter and yet to buy a battery shunt / monitor system.

Any guidance on how I can set up my system so battery charge levels do not fall below 50 percent would be much appreciated.

Cheers

Neil

Shut the inverter off when not in use. It probably has a 10 watt idle draw and will draw 250 watt hours a day. On a smaller system with just one 100 ah battery, that's 1/4 your usable production. If you go away and you come back after a cloudy week, this could drain the battery.

Other than that, figure out the electricity you want to use in watt hours, and use a solar calculator like in my signature block to determine how many panels to get.

Lead acid batteries top out at a 10% - 30% charge rate, more like towards the 10, so your solar charge controller should not exceed that limit. some are adjustable, others will put out to a max advertised. That is about 150 watts of panels per 100 AH of battery pack. So in addition to sizing a lead acid battery bank for watt hours, you also have to size it to be charged no higher than this max rate.

Since you already have an inverter, I would not get an all in one. I also don't like all in ones because they tend to have higher idle draw.

If you wanted to, you coudl get a battery shunt with a programmable relay to automatically shut off the inverter.

Hi - Much appreciate the advice and I am very much interested in a programmable inverter. I am currently looking at the Koolertron - this seems nice kit but I would appreciate any ideas ?

Thanks again for taking the time to reply.

Neil