How to Charge a Battery--lead acid and lithium-ion batteries (2021)

This video will show how to charge a battery (lead acid and lithium-ion), how to read battery rating and what features to look for in a battery charger.

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Related products in video.
12V Sealed Lead Acid Batteries:
12V 7AH Sealed Lead Acid Rechargeable Battery
2 pack--12V 7AH Sealed Lead Acid Rechargeable Battery
Smart Charger for 6V & 12V Sealed Lead Acid Batteries
Fully-Automatic Smart Charger, 6V and 12V Portable
14 AWG wire
12 AWG wire

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Check out my other videos:
How to Connect a Brushless DC Motor (BLDC) to Sensored & Sensorless Controllers (2021)
Powerful Electric Bike Conversion Part II--Lithium-ion Battery Power Boost Upgrade
Powerful Electric Bike Conversion Part I (E-Bike Conversion Kit Installation)
How to Connect a Brushless DC Motor to Controller (48V 750W E-Bike) in English

[tiffunny]

You are awesome! My brothers are all into computer/car tech stuff but are hard to reach so I’m so glad I found your video! It’s super informative and easy to follow! I’m going to watch all of your videos just to learn new things. Thank you!

[radioroger]

For many years I have charged them at 10% of AH rated value for 8 to 10 hours, and had good luck and batteries last for many years, use a rotary timer to shut the charger off

[aunttriciaattic]

Thanks for the video but the last three batteries I do recharge. The charger I purchased was on QVC I think

[hatrian]

Thank you! I did not know a higher amp output could damage a battery!

[Lee-haw]

What is the difference between a power supply, and a charger ?
Are they the same thing?
Some people say that the charger for a lithium ion battery in inside the pack itself as a BMS, battery management system.

[kenhalfen]

ALWAYS connect the terminals BEFORE you plug the charger into the wall outlet.

[spartty]

Nice tips thanks, My battery is Gel Valve Regulated and my charger is 12v -6amps is that ok for a 30ah battery? Do you also leave a battery like Lead Acid or any deep cycle ones unused for a certain period of time is it safe to stock or store a battery as a Reserve power bank if there will be power outages in our area? Thanks

[axemanners]

Can you use car battery chargers to charge these small 12v SLA batteries? (like from a jump starter battery pack). Thanks and very good video.

[Samuel-lmwb]

very informative. I did not know the lithium battery pack will come with a bms and a charger port. I thought I had to find one with it.

[undiscovad]

Question. One of my garage door batteries is rated 12v 2.2ah. I bought a 12v 2A charger, charged it for two hours but the voltage on the multimeter says 10.6V. Does this mean the battery is dead? Also after the charge, the battery temperature is warm.

[twitchalputsu]

How much time would it take would it take to charge a 12v 12ah SLA battery using the SLA smart charger?

[froglobster]

I don’t understand the charging time formula so I’ll ask.
For alarm panel I have a 6 volt 1.3 amp rechargeable lead calcium battery. How long do I charge this for
Thanks

[NickAlwynMeata]

I have a 12V 18ah battery. What is the best suitable solar panel to charge it?

[stevenolmstead]

I use (2) of these batteries in series to power a three-wheel golf push cart.

A round of golf normally lasts about 4 hours.

Should I charge the batteries after each use? You also recommended not overcharging them. My charger has a red/green light to indicate when they are charged. With this setup how do I avoid/know when to turn it off to avoid overcharging?

[kimmensman]

Thanks, very helpful. 65 year old single woman that is not smart about this stuff.

[tyg]

Hello, I’m wondering if I bought the black battery in your video to put under my driver seat and connect wires to power a siren for the car would that work?

[erickdominguez]

I didn’t charge my kids power wheel battery for one year the batteries dead can I still charge it?? It won’t charge with the charger

[stevenolmstead]

Thanks for the video. I just recently bought 2 12v 10ah lithium batteries. Do I need to charge them out of the box - or do they come precharged?

[lomgshorts]

OK,
Charging several 12V batteries, and I do not care what the manufacturers say. You must use a constant current, constant voltage charger on SLA, AGM, LIPO, or any other rechargeable battery. Why? This makes the battery last much longer that if you used a regular lead acid charger of any type. Between Amazon and eBay, you can find practically any voltage charger in existence. But you must find a constant current and constant voltage charger to maintain your battery for long past its warrantied lifetime. Don't be cheap on the charger! Remember, you get what you pay for, especially with Chinese made chargers. LiPo batteries have a problem, some Chinese make outlandish claims on their battery capacities, some by a factor of four! An 18650 battery from China rated at 9800 Mah, have been checked out at less than 2, 000 Mah on the bench. The weight of the battery determines the amount of current it can supply. If a 9800 Mah Chinese battery weighs less than a Japanese battery rated at the same current level, the heavier battery wins! Read the fine print under the ad giving the specs on that battery that looks so very affordable. Chances are that battery is a lightweight fake. (My opinion, my experiences). Oh, it may work well enough in a flashlight, but not for as long as they claim. Those bright yellow or red batteries ("eye candy") from China just do not measure up to Japanese batteries or some South Korean batteries. Look at the weight (in grams) when battery shopping, or for what its worth, in Wal-Mart and buy the heavier battery in its class (including car and marine deep cycle batteries). Bring a fishing scale of up to 60lbs if you have one for the heavier batteries. If a store complains, walk away, they have something to hide. In batteries, weight has everything to tell about a battery.

[MartinSage]

I have a large Sears auto charger. It is stamped Output 12VDC 2/10 Amp. It has 3 settings manual, auto cut off—regular and auto cut off—deep cycle. I’ve used it to charge both my regular Car lead 12V and regular motorcycle battery. I’m sure it will work on the e-bike lead battery but what about a lithium battery?