₦airaland Forum

feflo:
Battery Maintenance

Deep cycle batteries (lead-based) such as those used in off-grid solar power systems have much thicker lead plates than car batteries to make them last longer. Deep cycle batteries should never really be discharged to below 20% of their full capacity, because internal resistance causes heat and damage when they are recharged.

Renewable energy systems usually use a low-charge or low voltage warning light or a low-voltage cut-off switch to prevent the type of damage that will shorten the battery’s life.

Battery shelf life can be extended by storing them at a lower temperatures, because the chemical reactions in the batteries are slower. However, in order to reach their maximum voltage, batteries must be returned to room temperature. Therefore, most deep cycle battery manufacturers do not recommend refrigerating batteries.

While conventional deep cycle battery systems generally require a significant amount of oversight, the next generation of energy storage (lithium-ion) features highly automated management systems; with maintenance and monitoring basically nil.
Battery safety, explosions and other hazards

A battery explosion is caused by the misuse or malfunction of a battery, such as attempting to recharge a non-rechargeable battery or short circuiting a battery.

Explosions are most likely to occur when a short circuit generates very large currents. In addition, deep cycle batteries can release hydrogen when they are overcharged (due to electrolysis of the water in the electrolyte). Normally the gas dissipates quickly. However, this gas can be ignited by a nearby spark (for example, when removing the jumper cables).

Note: hydrogen gas production isn’t an issue with lithium-ion batteries.

Attempting to charge a battery beyond its electrical capacity, ie overcharging, can also lead to a battery explosion, leakage, or irreversible damage to the deep cycle battery. It may also cause damage to the components in which the overcharged battery is used.

When a conventional battery is recharged at an excessive rate, an explosive gas mixture of hydrogen and oxygen may be produced faster than it can escape from within the walls of the battery, leading to pressure build-up and the possibility of the battery case bursting.

In extreme cases, the battery acid may spray violently from the casing of the battery and cause injury.

Deep cycle batter explosions can also occur in maintenance free lead-acid batteries if the valves fail or are blocked. The pressure rises within the cells until a short-circuit ignites the hydrogen-oxygen mixture. Such explosions can cause severe injury. The problem can be detected in most batteries if the sides appear swollen, or if the battery feels hot to touch.

Culled from http://www.energymatters.com.au

feflo:
Sealed Lead Acid Batteries

Sealed lead acid batteries are also known as valve regulated lead acid (VRLA) batteries, recombinant batteries and often called maintenance-free lead-acid batteries. Examples of VRLA batteries are:
• Absorbed glass mat (or AGM)
• Gel cells

The term “seal lead acid battery” is misleading: a sealed battery would be a safety hazard due to overpressure risks the battery is overcharged. There is always a safety valve present, hence the name valve-regulated. Even the term “valve regulated” does not really describe this technology. These are really “recombinant” batteries. This means that oxygen evolved at the positive will mostly recombine with the hydrogen ready to evolve on the negative and thus prevent water loss. The valve is only a safety feature in case dangerous amounts of hydrogen are produced.

Flooded Lead Acid Batteries

Flooded lead acid batteries, or wet cells, are the oldest type of rechargeable battery still in use. This type of battery contains a liquid in an unsealed container. This means that the battery must be kept upright and in a well-ventilated area to ensure safe dispersal of the hydrogen gas produced by these batteries during overcharging. The lead-acid battery is also very heavy for the amount of electrical energy it can supply.
Flooded lead acid batteries require period monitoring and topping up with distilled water. Despite these disadvantages, flooded batteries have high surge current, easier to troubleshoot and are relatively inexpensive.

Gel Batteries

A gel battery (also known as a “gel cell”) is a sealed valve regulated lead-acid deep cycle battery and has a gel electrolyte. Unlike flooded lead-acid (wet cell) batteries, these batteries do not need to be kept upright. Gel cells virtually eliminate evaporation of the electrolyte, spillage (and subsequent corrosion issues) common to the flooded lead acid battery, and boast greater resistance to extreme temperatures, shock, and vibration. As a result, they are often used in automobiles, boats, aircraft, and other motorized vehicles.

Culled from http://www.energymatters.com.au

feflo:
More batteries

vitality22:
Engr Femi, please how much is this battery?

feflo:
Gel batteries

feflo:
Look for the buzzer, usually on the board and remove it.

Trippledots:
any flooded lead acid available 100ah or 150ah

getbizy:
Goodafternoon feflo, really liked ur tutorial on the APC UPS conversion, though u didnt reveal all.
Any particular reason as to why we remove the buzzer?
Thanks.

feflo:
I am not aware I didn't reveal all, many people called when they encountered challenge while doing it and I gladly put them through, I even sent several pictures to them to assist.

A UPS is designed/programmed to always sound alarm as long as its in UPS mode, by converting, your intention is to use it for several hours. The noise from the buzzer will constitute a nuisance if it continues sounding for hours on end thus the need for its removal.
Really appreciate your observation, will strive to reveal all on the next conversion.

Many thanks.

iamsuskay:
I really love ur articles it really interesting and educating more grease to ur elbow...plz nd plz
I need inverter setups details to power at least 8 or 5hours on 2 32'inches lcd/led t.v , one decoder, 2 standing fans nd 5 energy saver bulbs on dat I'm confused on it base on ur explanations..plz help ooo I need solid conclusion.

getbizy:
Whats the price range for the APC ups pls?

feflo:
Started the installation of 2.7kw solar system today 11th June at lekki. It includes:
1. 15pcs of 180w Yingli Solar panels
2. 48vdc 60amps epever charge controller
3. 10kva 48vdc local inverter
4. 24pcs 2vdc 500amps gel batteries
5. DC breaker, fuse box, racks etc

snipesdam:
@feflo....

I want to confirm these connections from you.

1. After setting up the fan inside the UPS. Can yo still setup another fan to bring IN cool Air from the other Side?

2. Do you also connect the UPS to AC power? (I DOUBT THIS SHAA JUST ASKING)

3. Battery terminals coming out of the UPS goes to the 100AH/200AH Battery terminal connected in series as the case maybe?

4. The charger also is connected the 100AH/200AH Battery terminals?

5. I have 1.5kva APC ups with 48VDC Charger and four (4) 200AH Batteries. Am i good to go anyheads up?

6. Also if possible can i connect a solar charger to it?

Thanks for your response in advance.

feflo:
I will attempt to answer the questions serially following your numbering sequence:

1. I don't think it's necessary, since the fan extract heat out of the system. What I may advice in this scenario is to perforate that other side instead of putting fan.

2. Yes of course, it has an inbuilt automatic change over switch, you can only activate it when the AC cord of the UPS is connected to mains.

3. Yes sir

4.Yes sir

5. Not really, the 1.5kva APC that I know is 24vdc so you'll need a 24vdc charger except your own 1.5kva is 48vdc which I very much doubt.

6. Yes sir

Many thanks.

snipesdam:
Back to Question 5.

The APC 1.5kva is exactly the same as the pictures you posted here.

So if the APC ups is 24vdc and i have 48vdc charger... What exactly could go wrong if used.. Cause i don't have money to buy another one ooo

Can i reduced my battery to two (2) thats two of 12v200AH. Since APC is 24vdc

Hugoboy:
Good day. Please how much will this kind of setup cost. I live in Oshogbo.

feflo:
It will not even work if used. Of course you can reduce your batteries to two.

feflo:
I will attempt to answer the questions serially following your numbering sequence:

1. I don't think it's necessary, since the fan extract heat out of the system. What I may advice in this scenario is to perforate that other side instead of putting fan.

2. Yes of course, it has an inbuilt automatic change over switch, you can only activate it when the AC cord of the UPS is connected to mains.

3. Yes sir

4.Yes sir

5. Not really, the 1.5kva APC that I know is 24vdc so you'll need a 24vdc charger except your own 1.5kva is 48vdc which I very much doubt.

6. Yes sir

Many thanks.