Welcome to Synthiam!

Program robots using technologies created from industry experts. ARC is our free-to-use robot programming software that makes features like vision recognition, navigation and artificial intelligence easy.

Get Started
United Kingdom
Asked — Edited

18650 Li-Ion Rechargable Batteries

Has anyone used 18650 Li-Ion rechargeable batteries before with the EZB.

I'm using two in series to get 7.2V @ 3400ma, the ones I chose were made by
Xtar and has built-in Protection, ( see photo ). The reason why I wanted to change from the standard 7.4v 1300ma Lithium-ion polymer battery, was the drain rate only gave me about 5 to 8 mins usage, before I needed to recharge, using it on my Hexapod with 20 Protower MG996R Servos.

The Batteries have built-in protection, and have a surge trip protection current of 7 Amps, which I would of thought would of been more than enough to use on my Hexapod, but they trip out on power on, I'm surprised the surge current is more than 7 amps?

The reason I went for these, rather than just getting a larger capacity Lithium-ion polymer battery, was because of the size and weight were small, compared with a polymer battery of 3400ma.

User-inserted image

AI Support Bot
Related Content
Synthiam
Based on your post activity, we found some content that may be interesting to you. Explore these other tutorials and community conversations.
#1  
I am and they work great... I built my own pack however (5200mA) using ones with soldered tabs....
United Kingdom
#2  
Richard
Do you know if these are the protected ones, I think usually ones with soldered tabs aren't protected?

I know these are used in Laptop batteries ( 6 in total, 3 of them in series for 11.1V ) and then 2 packs in parallel to double the current rating. The protection is on a separate board. I have a spare old laptop battery, which I might pull apart and build my own pack, but the weight may be to heavy! *stress*
#3  
I am not sure about the ones you have, but I know the pack I assembled doesn't have the protection IC included.... However, saying that my Li-Ion charger seems to peak charge them just fine... I am also mindful of not discharging them below 3.3V per cell.... Been using this pack for about 6 months now without any issues....
#5  
There are also heftier LI-ion cells 26650 instead of the 18650s. Also wiring in parallel will double the amp capacity.
United Kingdom
#6  
Yes, I looked at 26650's, but big in diameter ( 26mm Vs 18mm ) and a lot heavier, especially in a bulk pack.
United Kingdom
#7  
I've just been looking at these myself but the specs on the ones I found (not those in the first post but a different make) had a max current draw of 70mA which isn't exactly great. I can't find the max current draw of the xtar ones but I'm tempted to use them in my rover but I know the current draw will be way above 140mA (2 banks of 2 cells to give 7.2v and 5,100mAh)
United Kingdom
#8  
@Rich

For the Xtar ones I've seen a test spec of the surge trip protection current being
6.2 amps.

BUT there not good for using with 18x TowerPro MG996R Servos, I'm sending them back....

On EZB power on with servo's connected, the servo's twitch for a milli-second and then the trip protection cuts-in and voltage drops to zero.

I've taken some from a old laptop battery which don't have protection, and these work better, but only 2600ma each one.

By the way there's a lot of counterfeit ones out there on the market!

Ultrafire?
United Kingdom
#9  
I hadn't even considered them to be honest but my rover has a 6 AA battery compartment and these would probably fit in there with very little modification so it was an idea. I think I'll just stick to rechargable AAs for the moment, it will be (hopefully) finding it's way back to recharge on low power anyway.
Login to post a comment