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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61 views

Is there a minimum for charging current for lead acid battery?

I've recently bought a 9 V, 3 W solar panel that I wanted to use to make a small project in my balcony, then I bought a 6 V, 4000 mAh sealed lead acid battery, I want the solar panel to always charge ...
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53 views

Lead-acid battery Polarity Swap

I’ve seen people ask how to discharge a lead-acid battery, which is easy enough. I have a lead-acid battery that I must have connected to my on-board boat charger backwards. It must have been very ...
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50 views

Charging 4 x 12V lead acid battery with solar in series or parallel?

I have a small electric vehicle that currently uses 4 x 12V 8Ah SLA batteries wired in series as its 48V battery packs. I have 2 of these packs. In order to charge the batteries, I unplug all of them,...
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55 views

How does the charging curve of a deep-cycle lead-acid battery change as it degrades?

I am designing a circuit inside a UPS that periodically tests how long the battery can power the load. It does this by breifly disconnecting the power from the UPS and extrapolating from the measured ...
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105 views

Why does my 12V SLA Battery behave strangely when charged by simple LM317 circuit?

I'm currently working on a DIY alarm circuit and I have need of a charge controller for a 12V SLA battery. I picked up a XH-M603 charge controller (https://www.banggood.com/XH-M603-DC-12-24V-Charging-...
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30 views

Float charging current for AGM battery?

I have a no-name 2-stage trickle/float charger I bought "surplus" and I'm trying to decide whether to throw it out or not. It trickle charges a 35 Ah AGM battery up to 14.4V at 500 mA, then drops to ...
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58 views

Can Lead Acid and Lipo batteries be connected together to achieve higher resulting current?

I have a lead acid battery setup which has 3x12V 12Ah batteries connected in series resulting in 36V 12Ah output. I also have 3 LIPO batteries (1x11.1V 3300mAh, 1x11.1V 3000mAh and 1x12.6V 4500mAh). ...
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60 views

Is it possible to fully charge a 12V lead-acid traction battery using a car battery charger?

I got a 45Ah 12V traction battery for my experiments and I was assuming that I can recharge it using a normal car battery charger (the main difference between 12V car starting battery and 12V lead-...
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1answer
70 views

What are the covers behind the terminals for in lead-acid batteries?

Some lead-acid batteries have two extra covers behind the terminals (See the images below). I understand that the 6 holes in the row in front of the terminals are used to water the cells. But what is ...
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61 views

Lead-acid battery charging fixed current stage specification

This post doesn't question the charging process or its theory. I seek to understand how to read the battery manufacturer's requirement of fixed current stage. They prescribe a current to be held at ...
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69 views

Lead acid battery increasing current under constant voltage

I've found an old lead-acid battery and decided to check if it still is in a decent condition. I've opened all rubber caps and checked that the water level was still OK. It measured 10.5 V before I ...
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93 views

Will a 4 Ah 12 V battery be fine for a 2 A 12 V diaphragm pump + a Raspberry Pi?

I've got a 4 Ah 12 V lead acid battery which currently runs a Raspberry PI. I'd like to connect a diaphragm pump to this battery as well. The pump has a max. rating of 2 A. Assuming a fully charged ...
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641 views

What is the lowest voltage a 12V lead-acid battery in a car could be?

I'm trying to design a product that is powered from the 12V rail inside the car. In normal driving (engine running, electronics on etc.), what would be the minimum voltage of a low battery? Reading ...
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73 views

MPPT lead acid over voltage

As I understand it, an MPPT algorithm adjusts the charging voltage until it finds the point where maximum power is delivered into the battery. If a 12V lead-acid battery is used, is there an upper ...
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77 views

DIY Lead Acid powered USB-C power adapter [closed]

I recently found a great appreciation for the long battery life of my newly acquired mac book pro and was thinking how I can scale that up even more (since I travel and work on site a lot), by ...
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48 views

CSB batteries Constant Current Discharge Characteristics

I'm comparing batteries for use in UPSes and during my tests I was consulting the datasheets of 2 manufacturers. The datasheet from SunLight is crystal clear but CSB's datasheet is using terminology ...
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9 views

Battery Discharging and Effect on Lifespan

I have noticed that some times during the day when my solar system panel is shaded it starts using the battery bank power (a few ampers) for a few seconds and then recharges the battery after the ...
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2answers
186 views

Reserve Capacity Testing On Lead-Acid Car Battery

All car batteries have Reserve Capacity ratings instead of Ah ratings for deep-cycle batteries. Using this data to test the health of the car battery a good way to estimate life left? Let say I have ...
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285 views

Voltage drop on batteries when connected to ups/inverter

I have recently installed a solar system and trying to understand the voltages of batteries when they are being charged and when they are providing power to load. Here is what I observed: I have 2 ...
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74 views

What is 'DOC' in terms for Depth of Discharge for SLA batteries?

I'm trying to understand the spec of a SLA battery. There's a chart which is titled "Cycle Life in Relation to Depth of Discharge": Can I ask what 'DOC' stands for and the chart is read? How come ...
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1answer
186 views

Which AGM battery terminals should be used when wiring 3 or more batteries in parallel?

With a 12V AGM battery bank of 3 or more batteries wired in parallel, is charge able to be drawn by attaching to any random positive and negative terminal across the battery bank? Is it optimal to ...
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250 views

What is the effective equivalent battery capacity between Lithium Ion and Sealed Lead Acid batteries? [closed]

I was told by a battery salesperson that a Lithium Ion 100Ah battery is equivalent to a 260Ah lead acid battery bank. Is this correct? I understand that lead acid batteries should only be discharged ...
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60 views

ADC conditioning for Lead-Acid monitoring? [duplicate]

I want to monitor a 12V lead-acid battery using an ADS1110 ADC. This ADC has a reference voltage of 2.048V. Thus, I (think) need to condition my input from, say a 10V-15V level range to 2 volts (0.4 ...
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73 views

Substitute 12v Lead Acid Battery with Nominal 10.8v Lithium Ion Battery?

I am looking to replace an existing 12v Lead Acid battery configuration (two 7.5Ah batteries in parallel) for an old practice tennis ball machine. The machine consists of 12v dc motors and sensors to ...
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42 views

Do I need a cut off circuit for my battery

Do I really need an auto cut off circuit for my battery when my charger only outputs 13V and 1A at max. The battery I want to charge is a 12V 7Ah Sealed Lead Acid. I heard that the cut off for lead ...
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89 views

trickle charge backup battery

I would like to know if the schematic below would work to keep a 12V SLA battery at or close to float voltage to be used as a backup battery? R1 will limit the charge current to the battery, but am I ...
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Using SLA in place of LFP to test an LFP charging device

I'm testing a solar charge controller for LiFePO4 that uses absorption and float stages. By design, power-on initiates the absorption stage, and a timer terminates absorption and initiates the float ...
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80 views

Sealed lead-acid battery UPS indoor?

I bought a BX700UI APC UPS for my linux arm server setup (40 watts) to protect it from power cut. - I have the server in the bedroom is it dangerous to have such an Ups in a small bedroom? - Thinking ...
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54 views

charging 12v lead acid battery with OEM charger [closed]

I have an ExpertPower 12V 7 Amp EXP1270 Rechargeable Lead Acid Battery (link on Amazon here) and would like to safely charge it. Do you think this charger (Battery Tender 021-0123 -- link here) is an ...
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2k views

How much current can lead acid batteries safely supply?

I have a motor I wish to drive with an 18V lead acid battery. The motor can draw quite a lot of current when stalling and I am worried of overdischarging the lead acid battery. Unlike LiPo batteries ...
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1k views

Mixing Lead acid and Lithium ion in series, after charging them separately

Can I connect a Lithium ion battery battery pack with a Lead acid battery bank; in series. I will charge both separately cells strings separately (not to mix the chemistries) before putting them in ...
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1answer
29 views

Designing an effective extensible solar cell + car battery setup [closed]

I've got a cabin that I visit on weekends and because I need to charge my computer and tools there, I decided to bring an old car battery and bought a solar panel to charge it. Right now I use a cheap ...
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202 views

Parallel connection of old and new gel batteries [closed]

I have a battery system shown in the picture, 6 parallel branches of 4 batteries connected in series. The first 3 consist of old batteries which are 2 years old, the fourth branch consists of 1.5-...
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3answers
479 views

Car battery (lead acid) discharges much, much faster than it charges?

Let's assume a lead acid car battery (12V, 50Ah, 250A output). According to BatteryUniversity article BU-403: The charge time is 12–16 hours and up to 36–48 hours for large stationary batteries. ...
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2answers
131 views

Charging a lead acid battery with a lower bulk voltage

Will a lead-acid battery completely charge when using a bulk voltage below the one indicated on the specs sheets for it, even if it takes longer? In my case the battery is in a place with temperature ...
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126 views

Is my 12v lead acid battery 100% dead?

so I got a ups with a 12v lead acid battery that was constantly on so the water inside the cells has disappeared, initially the reading voltage was 0.3v, and when I added distilled water it generally ...
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267 views

How to limit HV capacitor charging current?

I have a voltage doubler, which is connected to mains (without galvanic isolation): It enticed me with its simplicity, configurability and option between charging speed or desulfatability. The ...
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1answer
96 views

Using li-ion battery in place of a lead acid one in a desk lamp [closed]

I have a rechargeable desk led lamp with USB power input. Although it's supposed to hold charge, it only works when plugged. I opened it and found that the problem is about included lead acid ...
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176 views

Lead acid battery charging current dosent become zero

Here I am charging a 6V 4.5Ah lead acid battery by using a 8V-10V LM317 input supply for the circuit. I'm using the BD139 transistor to cut off and a 6.8V zener diode. As the battery voltage reaches ...
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152 views

How much input voltage is required to get 12v from LM2596?

I am trying to run WiFi router from a 12v lead acid ups battery. To get a stable 12v output from the battery I used LM2596. Problem is output is always 8.28v-8.50v. No matter how many times I spin ...
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136 views

Why do lead-acid batteries only last for a few years? [closed]

Why do lead-acid (automotive-style) batteries typically only last for a few years of regular use (or x amount of cycles) before having problems? Obviously, things can't last forever. But, what are ...
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253 views

refilling 4v lead acid battery

in my case i have some 4v lead acid battery laying around.... and i have not used for a while so obviously they are dead or dried out.... i tried to search some way or result on how to refill it... ...
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78 views

Slow-start lead-acid charge - good or bad?

I have a 300Ah battery which is near-dead (Abused in the past, around 5 years old) and want to replace it with 4-6 new 100Ah. The current method of charging is with a 30A MPPT solar controller. As ...
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1answer
58 views

Switch off branch of a circuit when voltage is present in another branch [power path management]

I want to convert a circuit that runs on 6V DC (from an intermitent power source) to a battery-operated one, by adding a Sealed Lead-Acid (SLA) battery. This would fulfill the following scenarios: ...
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90 views

Question about lead acid batteries? [duplicate]

I am having two batteries of different specs (both, dry cell, UPS/inverter batteries) Battery A: 12 V, 26 Ah Battery B: 12 V, 7.2 Ah I need a 24 V output so I have connected them in series. My ...
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744 views

Li-Ion Power Pack vs Deep Cycle 12V Battery?

I've seen a number of videos on YouTube where people have built a "Power Box" by putting a 12V deep cycle battery in some kind of weatherproof box with a charging equipment and added various switches ...
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75 views

Least sub-optimal configuration of flooded lead-acid cells with different capacities

I am aware it's best to use cells of the same capacity, same age, etc. However, until I can replace the cells I have I need to make use of these. The batteries I have are 2V flooded lead-acid cells, ...
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319 views

What is the actual capacity & charging current of a given deep cycle lead acid battery?

Firstly let me say that this is with a view to using a lead acid battery for backup purposes in case of power outage (mains power, a few lightbulbs but with daily outages lasting a few hours) So let'...
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61 views

Is the mobile charger capable of charging an SLA?

The referenced article over on http://www.instructables.com/id/4V-Lead-Acid-Battery-Charger/ indicates a Li Ion charger for mobile phones may serve to charge a low AH SLA. I held the impression a Li ...
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1answer
299 views

Charging lead-acid battery in parallel with load - what if the system voltage goes above nominal, and how to prevent it?

I have just purchased a 6V, 4.5Ah sealed lead-acid to power my arduino-controlled bicycle LED lighting system. The battery is to be charged by the variable power provided by a hub generator, which ...