How do I properly charge my LIPO battery?

In summary, a battery has a number of cells in series. You should use a Battery Management Module to keep the cells balanced. Do you have access to the inernal connection between the two cells?No, I do not have access to the internal connection.
  • #1
Lookitsame
3
2
TL;DR Summary
Charging Lipo question
Hey, I just purchased a lipo battery and was wondering if I wanted to charge it would I be able to use a 6v/3amp charger for the following lipo 7.4v/10amp. I'm pretty sure I would be able to.

LIPO BATTERY:
https://www.robotshop.com/ca/en/74v-2000mah-5c-lipo-battery.html

What is the general rule of thumb for charging lipos? Charge at .5c and don't go over the voltage

Thank you so much
 
Engineering news on Phys.org
  • #2
  • #3
Actually 7.4 V LiPo requires a charger capable of charging up to 8.4 V. That's the voltage of full 2S battery.
 
  • #4
Another thing to keep in mind is that Li ion batteries are somewhat picky when it comes to overcharging.

If you have little or no experience with this I would strongly recommend acquiring a purpose built 2 cell battery charger, lest you burn your house down or cause injury.

 
  • Like
Likes hutchphd
  • #5
Hey, thanks everyone for your comments, taking everything in I'll get a battery charger meant for a 7.4v lipo (https://www.robotshop.com/ca/en/74v-lipo-battery-charger.html) I would also get a BMS but I was planning to hook up the leads of the battery to a buck convertor that would give me an output of 12V to power a 12v/3a device (https://www.amazon.com/dp/B00PELQA7M/?tag=pfamazon01-20).

Would it be ideal to still use a BMS or can I get away without using one

Also in response to Baluncore I don't have access to the internal connection and from reading the reviews on the battery there are several wires for different connection options also there is no datasheet for this device online so I'm going off the assumption that there is no internal management module.
 
Last edited:
  • #6
Lookitsame said:
taking everything in I'll get a battery charger meant for a 7.4v lipo
Thank you for that. IMO, batteries (especially advanced chemistry batteries) are just too dangerous to try to do DIY chargers, unless you have a very strong EE background and are willing to do a lot of research into the appropriate recharging technologies.
 
  • #7
Lookitsame said:
... I don't have access to the internal connection ...
Then you cannot connect a BMS.

Lookitsame said:
... I was planning to hook up the leads of the battery to a buck convertor that would give me an output of 12V to power a 12v/3a device ...
You need a BOOST converter, NOT a buck converter. A buck can only cut = reduce the voltage.
Avoid an LED voltmeter if you can as it wastes battery energy.
 
  • Informative
Likes berkeman
  • #8
Lookitsame said:
Summary:: Charging Lipo question

Hey, I just purchased a lipo battery and was wondering if I wanted to charge it would I be able to use a 6v/3amp charger for the following lipo 7.4v/10amp. I'm pretty sure I would be able to.

LIPO BATTERY:
https://www.robotshop.com/ca/en/74v-2000mah-5c-lipo-battery.html

What is the general rule of thumb for charging lipos? Charge at .5c and don't go over the voltage

Thank you so much

The battery you pictured does have a BMS port (the 3 wire one).

Why did you get a 2s battery if you need to supply 12V ? One more cell (3S) gets you above 11 and that will probably do fine...these batteries don't go low until the very end of charge.
I concur that building a charger is a bad idea.
These batteries hate to be completely discharged and seem to store long term best with ~60% charge
 
  • #10
Baluncore said:
You need a BOOST converter, NOT a buck converter. A buck can only cut = reduce the voltage.
Avoid an LED voltmeter if you can as it wastes battery energy.
Thank you for pointing that out, that clears things up now I'll go ahead and get this one (https://www.amazon.com/dp/B00MIJL4OC/?tag=pfamazon01-20).

hutchphd said:
Why did you get a 2s battery if you need to supply 12V ?
The main reason is this one weighs much less than the 3s battery and since weight is a big issue for my project I decided to get the 2s battery.

EDIT: Thank you, everyone, for your responses I decided I am getting this (https://www.amazon.com/TalentCell-Rechargeable-3000mAh-Lithium-External/dp/B01M7Z9Z1N/ref=sr_1_9?crid=3PCA2G1QMMSZ6&keywords=battery+management+system+12v&qid=1587867792&sprefix=battery+manage,aps,190&sr=8-9) it would be a 100 times easier as it outputs the exact voltage and current and also seems it has a BMS embedded within in. Learned a lot from your responses, great learning experience thanks a lot :)
 
  • Like
Likes berkeman and hutchphd
  • #11
Lookitsame said:
Thank you for pointing that out, that clears things up now I'll go ahead and get this one
That is a better choice.
When you get it, connect a few hundred ohms to the output and adjust the constant voltage CV to your required regulated output voltage. Then adjust the maximum current limit needed with CC, which will limit short circuit fault current and prevent regulator overheating.
 
  • Like
Likes hutchphd

1. How often should I charge my LIPO battery?

It is recommended to charge your LIPO battery after each use, regardless of how much power was used. This helps to maintain the overall health and longevity of the battery.

2. Can I leave my LIPO battery charging overnight?

No, it is not recommended to leave your LIPO battery charging overnight as it can overcharge and potentially cause damage to the battery. It is important to monitor the charging process and unplug the battery once it is fully charged.

3. What is the best way to store a LIPO battery?

LIPO batteries should be stored at approximately 50% charge in a cool, dry place. Avoid storing them in extreme temperatures or direct sunlight, as this can affect the performance and lifespan of the battery.

4. Can I use any charger to charge my LIPO battery?

No, it is important to use a charger specifically designed for LIPO batteries. These chargers have the necessary safety features and voltage settings to properly charge and balance the cells in the battery.

5. How do I know when my LIPO battery is fully charged?

Most LIPO chargers have a built-in voltage checker that will indicate when the battery is fully charged. Additionally, the battery may feel slightly warm to the touch and the charger may display a green light or indicator when the battery is fully charged.

Similar threads

  • Electrical Engineering
Replies
11
Views
185
  • Electrical Engineering
Replies
7
Views
2K
  • Electrical Engineering
2
Replies
40
Views
4K
  • Electrical Engineering
Replies
2
Views
1K
  • Electrical Engineering
Replies
1
Views
1K
Replies
4
Views
8K
  • General Engineering
Replies
6
Views
17K
Replies
1
Views
2K
Replies
10
Views
4K
  • DIY Projects
Replies
28
Views
2K
Back
Top