Questions tagged [lead-acid]

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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Two 12 V lead-acid batteries unevenly loaded

A contractor installed a battery-powered lift in my house. It contains 3x2 12 V lead-acid batteries (2x12 V in series, 3x24 V in parallel) which are charged in every station of the lift. The lift is ...
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Durability of a battery

I have a device that consumes 10W and I have a 12V x 4.5Ah = 54Wh lead-acid battery, does that mean that my device can work continuously for 5.4 hours? Does the same concept apply to lithium batteries?...
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Can I charge lead-acid batteries with more current than their rating?

I have a solar charge controller with these specs: Type: PWM-Type Solar Charge Controller, 30A, 12V/24V Battery type: DC 12V/24V (auto-detect) Charge current: 30A Discharge current: 30A USB output: ...
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BMS with lead-acid battery pack

I assembled a lead-acid battery pack with six batteries. Is it possible to add a BMS for a lead-acid battery?
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Why is my lead acid battery suddenly dead?

I have a 12v 12ah sealed lead acid battery that was used 3 years in a battery friendly environment. Now I wanted to use it to power a security camera. I use a cv cc buck converter as a charger. I ...
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What's the minimum float voltage to maintain a small lead-acid battery?

I wish to 'float' a Yuasa Y7-12 7 Ah, 12V sealed lead acid battery. On Battery University it says that a voltage of 2.25-2.3 V per cell (so 13.5 - 13.8 V) will allow a lead-acid battery to regulate ...
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New deep cycle batteries produce low capacity and strange voltage behaviour

Batteries: Royal 1150k 105ah(20h) Reserve capacity 180min(25A) Inverter Load :27.5amp(constant)..measured. My battery is lasting 30mins on this load. When starting discharge from full it quickly drops ...
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How can a solar battery charger without separate load connection include three stage charging?

As you may know, there are several solar battery chargers (e.g. mppt Victronenergy ones) that only provide 2 connections, one to the battery and one to the solar panels. So, no separate load ...
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Resistive current sensor shows reading when I connect it in series with a battery while no current is flowing through it

I need to monitor the charge and discharge current of two 12V lead-acid batteries in series using an INA219 current sensor, and a 0.75 mOhm shunt. At first, I placed the current shunt in the low side ...
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Why do I hear hissing sounds when I discharge my sealed lead acid batteries at high currents?

I've been doing some discharge tests in order to figure out the Peukert exponents of two sealed lead acid batteries with capacities 7 and 9 Ah, in addition to an initial current of 2.1 and 2.7 A, ...
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12V boat lead acid battery suddenly failed

Battery on boat and powered by solar panels started acting really weird suddenly exactly a week ago. App shows voltage went from minimum 12.3V to min 6V in a day. On board voltmeter showing 11.9-12.2 ...
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Is battery charge efficiency related to its self-discharge?

I've read a couple of research papers and technical user manuals concerning SOC estimation, all of which mentioned both charge efficiency and Self-discharge but did not mention whether these effects ...
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DIY lead acid battery

I need a battery to act as capacitor for a small generator (~7V peak) which does not produce smooth DC. Normal capacitors are unable to deal with ~0.2 second dead time when load is attached, lithium ...
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Power camping lantern with 12v AGM battery

I have a 3 AA battery powered LED camping light/lantern. It draws (measured with a multimeter in series) about 18 mA when ON and 0 mA when OFF (ON/OFF controlled by a switch button). It’s ON all night ...
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Can you use a 12V lead acid battery to switch a contactor?

So I'm making a manual precharge circuit for a solar car's motor controllers, and need to use a 12 V source to switch a contactor on/off thus switching between a resistive path and a short circuit ...
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Charge a 12V 90Ah led acid battery using 12V 20A SMPS

Let's assume I have a 12V 90Ah battery and 12V(15v max) 20A SMPS. I want to use this SMPS to charge the battery. I heard that 1/10 of the battery current is good to charge the battery. So that means ...
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Circuit to charge three lead acid batteries in parallel and discharge them in series

I have three 12V lead acid batteries. I want to charge them in parallel and discharge them in series. I designed a circuit using switches and SPDT switches. The simulation works, but I was hoping a ...
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Can I directly connect four lead acid batteries for UPS (MeanWell ADD-155C)? Which voltage should I set?

I want to power my Mikrotik HEX POE switch which accepts up to 57V DC through a DIY UPS. I want to build it from a MeanWell ADD-155C which haa battery connector (<...
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How to regulate voltage from marine battery? [closed]

I have a telescope with a number of components that run on 12vdc. I want to create some sort of power regulator to supply power to my components without frying anything. Is there some kind of voltage ...
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Can I run a hairdryer from a 2000W pure-sine inverter connected to my starter battery, if my engine is running?

I'd like to occasionally be able to use a 1600W hairdryer for ~10 minutes. Maybe once a week, but only ever after a significant drive (and hence a well-charged starter battery.) My starter battery is ...
3 votes
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How does this circuit work? (24 V lead-acid charger)

How should this circuit be controlled to ensure that the backup battery is properly charged? The battery is a 24 V lead-acid battery. This is a circuit diagram of a UPS device. A PWM signal is ...
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Stepper Motor Driver Current Regulation: Lead Acid Batteries

I'm controlling two NEMA 34 6A stepper motors through HSS86 stepper motor drivers. The drivers take AC and DC, between 20 and 80v. I'm using them to control a golf cart via remote control, and I ...
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How to calculate watt hours gained charging battery?

I need an estimate of how many watt hours a battery has gained after charging to a certain number of volts. With a 12 V, 50 Ah lead-acid car battery, charged from 12.5 V to 13.0 V, is it as simple as ...
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Keeping sealed lead acid battery bank in good condition - and science behind

I will have 2 lesuire batteries on the boat. The bank will be 12 V and 150 or 220 Ah (not sure yet). I am trying to find out if constantly delivering low current (say 0.1) before charged and later ...
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How to measure the voltage of a battery under load to roughly estimate remaining charge?

I am designing a system where I'll need to use a micro controller to measure the voltage of a 12V lead acid battery to determine it's state of charge. I was planning to simply use a voltage divider ...
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Lead acid battery charger

I designed the below circuit. The relay open above 13V and close below 13V. How can I make relay open above 14V and close below 12V? Tell me if the circuit have major problem. Thank you.
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What are the differences in procedures in charging lead-acid batteries vs. lithium-ion batteries?

So I thought that lead-acid batteries are preferred, because you would only need to apply the maximum specified voltage (mostly 14.4 V for pure lead-acid and 14.7 V for the AGM/EFB, correct?) and ...
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SLA battery + MPPT use in a go kart

I'm building a hybrid PV/battery kart that is intended to weigh 120 kg with driver and average 30 km/h on a flat tarmac go kart track in full sun. I'm expecting that to require average power of 48 V x ...
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How to fix oscillation of an 'over-discharge protection' circuit for a lead-acid battery

I've created a circuit to protect my lead-acid battery from over-discharging. I used the following circuit diagram. Over-discharge protection circuit for a lead acid battery: For understandable ...
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Add old lead acids to parallel or replace them

I have some old lead acids they are the same brand they bought at the same time SLA maintenance free 12 V @12 Ah. I have measured their current capacities with a dummy load to about 3.6 Ah and 6 Ah. I ...
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Why does output voltage drop when charging battery? [closed]

I'm an electrochemical engineer. I saw a video showing although the output voltage from transformer is about 16.5V without connection, the voltage immediately drops to 9.86V, slightly higher than the ...
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What is the optimal current for charging two 12V batteries in series?

I have to charge two 12 V, 184 Ah lead-acid batteries in a series circuit. I have read that the provided current should be the 10% of the Ah rating of the battery, e.g. in this case it would be 18.4 A ...
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Safe Continuous Discharge Rate of a Car Battery

I have a car battery (Varta Silver Line of Products) that's rated at 110Ah, and 900A Cold Cranking Amps. The marketing of the battery from different sources says "huge reserve capacity" but ...
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Why are lead acid battery cutoff voltages inversely proportional to discharge time and is it OK to discharge down to 1.6 Volts per cell at C0.25?

I'm sorry if this is an obvious question, but I've been scratching my head with it for a while. I am used to UPS backup batteries that have an autonomy time between 2 to 4 hours, so I have always ...
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Will powering a device with a source that can provide more current than the device needs damage the device? [duplicate]

I am trying to build a power supply for my LCD monitor. It consumes 19.5V and 1.7 amperes. I am using a 12 volt 16 ampere lead acid battery. I have used a step up boost converter to increase the ...
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What cutoff voltage should be adopted for a given current using a lead acid battery?

From what I understood about lead acid batteries their capacity is related to the current drawn: the more current I draw from a battery, the less "effective" capacity I obtain, which means ...
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Can you monitor the state of charge of lead-acid batteries through their terminal voltage if they're being used?

Lead-acid batteries have -approximately- linear discharge curves and are therefore more easily monitored through their open-circuit voltage. Is there a way to monitor their SoC without disconnecting ...
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Can I use medical injection water to fill lead acid battery?

Can I use sodium chloride injection ip (0.9% W/V) instead of distilled water to fill a lead acid battery?
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Making easy 12V 100Ah battery charger circuit at home

I need a charger for a 100Ah battery and decided to make one. Now I need to order components and am asking for some help. I'm following tutorial at this website. Here is the circuit: I'm curious why ...
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Solar MPPT, 24v deep-cycle battery wiring (Parallel and Series combined)

I'm asking here in case any of you can offer some insight, I have 4 x 110AH 12v Leisure deep-cycle lead-acid batteries; wires in series and parallel to bring the array voltage to 24v. I have 200w PV (...
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Does Peukert's Law affect charging of lead-acid batteries in addition to discharging?

From Peukert's Law, we know that when discharging a lead-acid battery, if the discharge rate is high, the effective capacity of the battery will be reduced due to the battery reaching a minimum cutoff ...
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Adding a monitor to a multi-stage lead acid battery charger; charger never idles [closed]

I have bought a cheap 24V multi-stages battery charger (Qili QL-09005-B2402000H) to charge two identical 12v lead acid gel batteries in series. I cannot link to the item because it's not available for ...
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What does "CA" stand for on a lead acid rechargable battery data sheet

I am trying to use the following NP2-12FR Yuasa lead acid battery for a portable speaker project. I'm looking at the datasheet and I am a bit bamboozled by these two graphs. What do the different ...
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Lead acid battery: What happens if very low charging current is applied for an extended period?

What would happen to a 40 Ah lead acid battery if the charging current is as low as 750 mA? Would it get charged to its full capacity, say from 12 V to 12.7 V after a long duration or go permanently ...
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Charging lead-acid batteries via a boost converter. Are my calculations right?

I want to charge my two lead-acid batteries connected in series to a stair-case lift. I do not have a proper charger (don't have ebay/amazon here) but I do have a 19V, 3A laptop charger (SMPS). I also ...
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Float charging 12v lead acid battery

I'm trying to float charge a 12v car battery with constant voltage charging set to 13.5v. At start the battery voltage was 12.65. After 2 days it's up to 13.2 which seems higher than it should be. ...
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How to charge SLA battery?

I bought an ExpertPower EXP-1270 12v 7Ah battery, and I want to know how to charge it. I don't have a battery charger, but I want to do it with my variable power supply. I had already set it to 13.8v, ...
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Stair lift lead-acid batteries - dead after 1 month

I encountered the following issue: the lead-acid batteries (2 * 12V 7Ah) that power up the stair lift motor (24V, 0.3 kW) died ...
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Expected real capacity of Pb battery

I have a 12V "non-spillable sealed lead acid battery" (the UPS type) that is labeled to be 9Ah (it is almost new). When I fully charge it and then discharge using a discharger that counts ...
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Can I wire a 12V car battery to the 12v cigeratte lighter plug?

I have a van for summer travel and I am considering wiring up a car battery directly off of a 12V cigarette port which is rated at 20A by the car company. If both batteries were well charged at the ...

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