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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Using LM393 For SLA Battery Management
I had an old 6V SLA battery laying around, so I thought that it would be a great exercise to design a Battery Management circuit for it. Is the following circuit, based on the LM393, sufficiently good ...
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Charging Lead Acid battery using SMPS - unexpected voltage measured at battery
I am trying to charge a discharged 12 V Car Lead Acid Battery using a SMPS. According to voltage information provided for charging lead acid battery (https://batteryuniversity.com/learn/article/...
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Is off grid solar setup limited by battery charging current?
This question is strictly regarding off grid solar power setup, using PV panel, MPPT Charge controller, battery and an inverter to convert DC to AC.
Am I limited by the input charging current a lead ...
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Electric cart circuit, editied [duplicate]
I am trying to make an electric go-kart. I am new to the forum, so I may be missing some information but any help is greatly appreciated. After doing some math and discussing with friends I found the ...
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32 views
MPPT power balance constraints [closed]
I am implementing an MPPT controller cascaded with a battery charging controller to charge a lead acid battery. The question has to do with my understanding of how MPPT works. From what I understand ...
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1answer
65 views
Lead acid battery charging @ 0.2C
I am charging a 26 Ah battery with a solar charge controller. The battery's manufacturer recommends charging with 0.1C. Which charges the battery at 2.6A during bulk mode. That is what I was going to ...
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193 views
Charging lead acid batteries in parallel? [closed]
I recently got my hands on eight 12V 9AH lead acid batteries. Could I simply place them in parallel and charge them with a battery tender without any special measures? Are there any risks involved? ...
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81 views
Old lead-acid battery inrush charging current
Can an old lead-acid battery have an usually high inrush charging current, such that the alternator belt squeals for the first 30-90 seconds after the engine is started? It is worse in hot weather.
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What is the right voltage to charge a flooded lead acid at CV? Also it got pretty warm while filling up acid
Recently purchased a Yuasa PowerSport (6N5.5-1D- 6V 5.5Ah) bike battery. Since Amazon does not sell it with the acid it has to be purchased separately from an auto store or self prepared. I went with ...
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56 views
Do revived dead batteries become less effective?
There's a common belief that once a car battery dies, after it gets jump started, it will never be as good as before, and will likely die again. I'm curious whether this is a myth, or if not - what's ...
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47 views
Super simple: Convention for connecting batteries in series to load
Super simple question. I am new to electronics and have to connect 4 12V lead-acid batteries in series. Once I connect the negative terminals of each battery to the positive terminals of the others, ...
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68 views
What is wrong with this battery
I recently encountered a battery that was installed in a vintage lawn mower. The battery was dated 9/19 but would not start the engine, it would not even cause the relay to click. The voltage on the ...
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Charging three lead acid batteries in parallel with a single 14V charger
I need a 36V battery for a project of mine. Eventually I will buy a li-ion pack but now when prototyping and testing I don't want to spend a lot of money so I'm looking at cheap alternatives.
I'm ...
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37 views
Lead acid battery and lead acid battery charger — specs don't match, but can I use them anyway?
I have the following:
Lead acid battery
Specs: 12V, 7.2 Ah
Model: Portalac PXL12072
Description: Kind of old, so maybe sulfated, but I won't know until I try to charge it.
Lead acid battery ...
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84 views
Robust low battery cutoff
I am building a 5V DC charger for an offroad motorbike. The main goal is to use this to charge/power a mobile device/phone/tablet whilst travelling/camping.
If space allows maybe also a GPS tracker ...
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1answer
73 views
Can de-ionized water be used instead of distilled water to prepare lead acid battery electrolyte?
I have a couple of Yuasa and Power Sonic conventional lead-acid bike batteries that I recently purchased for a very good bargain price from a seller. They are new and never used. But unfortunately, ...
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135 views
How to check with a simple multimeter whether an old lead-acid battery and its charger are still working?
I have an old (ca. 10 years old) 6V lead-acid battery and a mains charger for it and I know the combination worked years ago.
Now I tried to recharge the battery and the charger's LED turns on ...
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80 views
Why don't the current readings fall to zero after unplugging the charger? [closed]
I use an automatic charger to charge my lead acid battery. After the battery is fully charged, it shifts to maintain mode where the charging current reduces to as low as 13 mA. I noticed that even ...
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62 views
Help understanding RV/Marine battery chargers
I am trying to understand how modern 3-stage marine/RV lead-acid battery charge systems work. It's very common to wire a charger in parallel with both the battery bank and the "house" power. This ...
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36 views
Circuit Charging Sealed Lead-Acid Battery (NP1270M)
I have a project (remote gate opener...) I have made good progress but its the first time I have built a charging circuit so I have some questions I need help with.
The battery I am using is a sealed ...
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94 views
What is the Ah to voltage relationship of a 12 V lead acid battery?
I've a DC motor (brushed) that is driven by a set of 12 Ah 12 V lead-acid batteries. When motor stops moving, I assume that all the current (at least most of it) in the batteries is drained. However, ...
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54 views
Do I choose a series or parallel battery set up to power a fish finder?
I plan on running a Garmin UHD 73SV fish finder off two 12V 7A lead acid batteries for a kayak. The unit pulls 1.25Ah. So if I run them in parallel I will have 12v 14A with a run time of about 11.2 ...
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70 views
Connecting multiple chargers to a lead acid battery
I have a scenario where I want to connect an external battery charger to an alarm system's battery to keep it charged fully despite our country's frequent rolling blackouts. The battery is a larger ...
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1answer
75 views
Choosing a resistor for balancing lead acid batteries
I have a solar-panel-and-battery kit with a built-in inverter and what not built into the battery box. (Goal Zero Yeti 400) The battery box has Anderson Powerpole connectors for chaining it to ...
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61 views
Limit current when charging a battery?
So I am trying to charge a 12V 1.3Ah lead-acid battery(actually they are two 6V batteries in series). Now I have a power supply which says 12V 500mA but actually outputs more like 21V.. No idea why.. ...
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Charging a big battery with small solar panels very very slowly
I have a 6V, .7amp solar panel that typically puts out 2-5V under normal conditions.
I would like to charge a 12V 5 amp hr lead acid battery over a few days to weeks.
The device that I want to ...
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1answer
78 views
On the possibility of lead acid battery recoverability [duplicate]
I have a 6 V 4.5 Ah lead acid battery which I did not charge for the last 6 months. Now the battery voltage fell to 3 volts and then I charged it for 24 hours at 50 mA. Now when I measure the voltage ...
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80 views
Lead-acid battery charger, specific circuit, 3~4.5 Amps, doubts + recommendations
I want to build a lead-acid battery charger which can reach an average charge current of 3 to 4.5A, and start with a prototype.
The charger needs to be supplied by the mains, up to 250VAC, for example....
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1answer
41 views
Confused about battery rating specifications [duplicate]
I'm confused about how to understand battery capacity by its ratings. I though I understood Amp-Hours, as a nominal rating where they usually specified a period of time where that rating was ...
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1answer
89 views
Why do lead-acid batteries perform better than Li-ion with substantially more ampere hour?
I've been using a 36V motor that draws ~13A current at peak. I initally used a set of three lead-acid (12V 12A) batteries in series to power the motor. They had sufficient power to easily take a ...
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167 views
Can lithium batteries and lead acid batteries be used together? [closed]
If I have the two batteries with same voltage but different capacity, can lithium batteries (the lfp battery like this type) and lead-acid batteries be used together?
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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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309 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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90 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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98 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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470 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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122 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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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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72 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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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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129 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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103 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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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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100 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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201 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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445 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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808 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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1answer
572 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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1answer
276 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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402 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 ...
