A type of very common chemistry system used batteries using lead and sulfuric acid. fully charged it will have a voltage of 13.8 V. These batteries are used in automotive and robotics environments.

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Many questions about charging a lead acid battery

Well, I have a 12V 9AH SLA Battery, and I use a 7815 + a diode in series to charge it, (I really wanted to build a charger using the L200 or the LM317 but I couldn't find any of those in my city). So, ...
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55 views

How to check what is the percentage of charge in my lead acid battery?

http://www.allbatteries.co.uk/media/pdf/AMP92108_FR.pdf I want to know how much percentage of the battery charge is left without buying any fancy equipment to measure it.
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70 views

What voltage and current do I need to charge a 4V Acid Battery?

I need to charge a 4V Lead Acid battery, but it is not clear what charging current and voltage I need. I checked many datasheets for 4V acid batteries, but I did not find anything that determines ...
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56 views

Switching Lead-Acid battery charger

Sorry if this question is a bit broad, or too part-suggestiony. I've been trying to find a good solution for over a month (and three board revisions) now, and I hope someone has an idea I haven't ...
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59 views

making battery charger for lead acid battery 6v

Hello so I was just given a 6v 4.5 Ah (4500mAh) sealed lead acid battery. I have never made a battery charger before but would like to make one now for this battery as it is for a robot I'm building. ...
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105 views

Some 12 volt sealed lead acid battery questions

(Update posted at bottom, I think it's solved but still open to advice) I recently received 2 12v 7ah batteries I ordered to replace the old ones in an electric skateboard. Upon receiving them, I ...
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110 views

To pulse or not to pulse

It is accepted practice to maintain lead acid batteries at a float voltage of roughly 2.3 Volts per cell .The precise value depends on battery type and battery chemistry and ambient temperature .We ...
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96 views

Is this a viable mini wind turbine setup?

I'm going to build my first wind turbine. I have already constructed the prop, 5 blades 50cm long from PVC pipes. I've searched for a decent sized motor and charge controller. The turbine will be ...
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195 views

Charging lead acid battery using boost/buck converter

I plan on permanently connecting a 12v lead acid battery to my home made wind turbine (dc). I already have a dc-dc buck/boost converter so I wonder if i can use that to charge the battery. ...
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56 views

Battery support capacity for inverter supply of 30A over 3hrs

I need to determine the 12VDC Ah capacity of a battery pack, to provide current to a 30A 120VAC circuit thru an inverter with 88% efficiency, where the voltage must not drop below 10vdc, over a period ...
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396 views

controller circuit for charging 12V 7AH Lead Acid battery from main source and Solar source

I need to have a controller for charging a 12V 7AH battery and provide uninterrupted supply. The source for charging would be 12VDC from a PSU or if there is a failure in that from a solar panel. I ...
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70 views

Lead Acid Battery Voltage rises very quickly

I am working on a charger for the first time. m charging a lead-acid battery (6V) by supplying a voltage of 7-7.2V & 100mA. But the voltage rises from 6.10 to 6.30 in just 5-10 seconds. What ...
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515 views

How do I charge a 6V, Lead Acid, 4.5 Ah battery using a 3W solar panel?

I have a solar panel with ratings: Vmp=8.8V and Imp=0.3A Using this i have to charge a 6V Lead Acid battery whose capacity is 4500mAh. I have searched the internet a lot and tried many circuits but ...
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1answer
77 views

Is it possible to regenerate lead-acid battery kept always charged?

I have a APC Back-UPS 280 I use for my server at home, and since power rarely fails, it is barely used. It only keeps the battery charged. The battery is 12 V, 7 Ah. After about 18 months it started ...
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248 views

Charging lead acid batteries using DC-DC Buck Converter

Is there any disadvantage using an 18V 2A transformer with an adjustable DC-DC buck converter(link below) to charge a 12v 7Ah battery ? I know that the charging current must not exceed C/10 (700mA ...
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108 views

Engine cranking corrupts SPI driven 7segment display

I am driving six 7-segment displays with SPI using MAX7219 and ATmega128. This is for displaying various engine parameters like rpm, oil pressure etc. for large marine diesel engines (>100 kW). The ...
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1answer
61 views

When does a battery self-discharge?

I want to measure lead acid battery self-discharge but I not sure when to trigger the self-discharge measurement algorithm. Is it constantly self-discharge or only in standby mode (no load)? If a ...
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1answer
180 views

Can I use 15V 2A transformer with this circuit?

I m trying to build a charger circuit for a 12V 7Ah Sealed Lead Acid Battery. I found this circuit online and it uses 15V-0-15V 1A Transformer as AC input. Circuit Source I have a 15V-0-15V 2A ...
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832 views

Simple piezo buzzer circuit--could I power it using a large battery?

I am fairly new to electronics. I was thinking about a simple circuit and was wondering if it would theoretically work or not. Say I wanted to connect a 12V Piezo buzzer to a switch and a large ...
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1answer
83 views

battery chargers - AGM and lithium

I am working on an inverter with a battery charger for a 24V,200AH AGM battery pack. The battery charger current can be adjusted from 10 to 50 amps. Now, I want to be able to also a charge a lithium ...
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454 views

Do I need to fully drain lead acid battery before charging them? [closed]

This is a follow up question based on this. I have an ebike which uses lead acid battery, my question is do I need to fully drain it before charging it again? How about when the battery is newly ...
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1answer
72 views

Number of cycles for AGM battery with an inverter

I have an AC system which has a continuous load of 7 amps at 120 volts. To run this system, I need a set of AGM battery and an Inverter system (power factor- 0.8). The inverter is 24 volts and rated ...
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134 views

Average current from a 4V lead acid battery

I am using three 4V rechargeable lead acid batteries in series as a power source for an embedded system. The logic system taps out 8V which is fed into an LM7805 and the 12V is used as input to an ...
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1answer
102 views

Lead Acid Battery Charge C/20Ah

I need to charge a lead acid battery, I will be manually developing a program to set the current. Its the "US 12V XC2" Deep Cycle battery. Here is a link to the datasheet: ...
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How bad is it to undervoltage a 12-volt lead-acid battery?

I had a heated discussion with a few colleagues today revolving around how low voltage was alright for 12 volt lead-acid battery (They were in the opinion that the low voltage warning buzzer and ...
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269 views

Can I Charge a 12V Battery While It's In Use? [closed]

I have a Time-Clock (Where employee's check-in and check-out to track working time). Currently set up like this: 12V Adapter >> Time Clock So whenever that 12V adapter loses power, the time clock ...
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1answer
263 views

How to attain a topping charge for a lead-acid battery?

Charging a lead-acid battery involves three stages: CC, CV, and Float. I have a charge controller which charges my battery at CC to the float voltage. I would like to add a device that would charge ...
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2answers
2k views

Are sealed lead-acid batteries safe to use indoors?

I have a small, 12V sealed lead-acid battery. I know regular lead-acid batteries can be dangerous to use or charge indoors, due to the fumes they release and the potential for acid to leak out or ...
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528 views

pulse charging lead acid battries effects and side effects

I am developing a solar charger which charges lead acid batteries.I would like to clear a few of doubts on this issue. I am using IR2110 gate driver for driving 2 n-channel mosfets in an half bridge ...
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3answers
102 views

How many 115ah wet lead acid batteries are safe to charge in the same space?

We are using about 10 115ah wet lead acid batteries to provide electricity for our business in the field. At night, we charge them all in the same space. The space does have a bit of airflow, but it's ...
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112 views

What is the effect of pulsed discharge on watt hour (Wh) efficiency of lead-acid batteries?

When discharging a (lead-acid) battery you see a voltage increase (volts rise) as soon as the discharge is paused. source: http://uu.diva-portal.org/smash/get/diva2:461718/FULLTEXT01 In the quest ...
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318 views

Recommended approach to create a lead acid battery level circuit

I want to build a battery level indicator circuit for a 12 V sealed lead acid battery. The battery indicator circuit will have two functions: It will power 4 LEDs to show the level of the battery ...
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1answer
144 views

Variable Current Lead Acid Battery Charging

I'm designing a solar controller in order to charge SLA batteries. I did some research on dedicated ICs that act as controllers, and found that most implement some sort of MPPT, in order to extract ...
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1answer
317 views

Creating a battery backup unit

I live in a area with frequent power failures lasting up to 5 hours. During this time I would like to power my router so that I can still use the internet with my phone/PC. I've looked at UPS ...
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1answer
41 views

charge a 12v battery from a cigar lighter

would I be right in thinking that to charge a 12v 7 ah sealed lead acid battery from a cigarette lighter socket on a canal boat, I would need to wire a bulb into the positive lead of the connecting ...
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488 views

Advice Running 3 10W 12V COB LED on a 12v7AH lead acid battery

I am planning on buying this LED ...
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108 views

Charging a bank of lead-acid batteries in paralel

I have a lead-acid battery similar to the one in the picture (mine is 15Ah) and I also have a spare car battery (50Ah). Is it safe, or a good idea to put them both in paralel to achieve a bigger ...
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1answer
265 views

Safe discharge cut off point for 12v SLI calcium lead acid battery

I want to make a circuit that cuts off a mains power inverter connected to a vehicle's battery. I have found, however, SLI batteries come with very sparse specifications. For example, the Varta E43 ...
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1answer
564 views

Solar charging using or not using a dummy (dump) load

I'm in the process of designing a small solar regulator / charger (no more than 5A) for sealed lead acid batteries. I have put a working prototype together and all seems to be working. However, ...
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199 views

Determine lead acid battery safe float charge level for a range of state-of-charge

My question: I want to know how to determine the highest safe voltage for a given SoC (state-of-charge). Or for a given float charge voltage, determine the lowest safe SoC. Helpful hints to the ...
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1answer
870 views

Charging Lead Acid Battery from dynamo

I want to build a Lead acid battery charger. for that I want to use a small IC engine coupled to a dynamo and the dynamo I got is rated at 12V, 35A and I want to charge 12V 7.5 Ah Lead Acid battery. ...
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220 views

Fast rising voltage on lead acid battery while charging

I have a couple of 12V sealed lead-acid batteries, which I have to charge. But when I hook one of them on the charger at 12V/1A (the battery is 10Ah) the voltage from 12.6 drastically increases up to ...
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3k views

What is the charge-discharge watt hour (Wh) efficiency for lead acid batteries at different SoC and charge current 10-35A/100Ah C10?

There is a 1996 Sandia study with the title "A study of lead-acid battery efficiency near top-of-charge and the impact on PV system design" for charge and discharge lead-acid battery amp hour [Ah] ...
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74 views

charging lead acid cells

And I have forklift battery 24V which is almost at the end of life. The 24V charger is very strong and heat battery and not working properly. I have one 12V battery charger, which works very fine. ...
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301 views

Modifying a Simple Transformer Circuit

I have a heavy 14.4V 1.5A heavy battery charger I would like to use to charge my car battery (over time, monitored for heat in a well ventilated area). When I plug the battery to the charger as is, ...
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2k views

Can I charge a Lead Acid Battery with a Lithium Ion Battery Charger [closed]

Can I use a charger meant for lithium ion batteries (eg a charger for a drill) to charge a lead acid car battery. It charges at 14.4V which is what I'm looking for (and will limit to 2Ah with ...
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4answers
363 views

Would a sulfated lead-acid battery charge at 2.1V per cell?

I'm trying to charge a 6-year-old OEM lead-acid battery in a 2008 Volkswagen Jetta with an external charger, whilst it's still connected within the vehicle. (The battery was working fine, until it ...
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551 views

Measuring internal resistance of a battery while it's being charged

I was startled to hear that there are devices out there that can measure the internal resistance of batteries, in circuit, while the batteries are being (trickle-)charged. For example, Hioki markets ...
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196 views

Charge condition of lead acid battery

I need to monitor the charge condition of an 8V lead acid battery. For monitoring purposes, I used a Beagle Bone Black (BBB) running Linux. It is also supplied via this battery. The battery also ...
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11k views

What is a safe max. discharge rate for a 12V lead acid battery?

I've got a 12V 2.4Ah lead acid battery which I plan to connect a water pump to. I've looked at various pumps, but the one I'm most interested in draws 2.2A. I'm not so interested in how long the ...