Go Back  R/C Tech Forums > General Forums > Radio and Electronics
Cheap charger for 4s >

Cheap charger for 4s

Community
Wiki Posts
Search

Cheap charger for 4s

Thread Tools
 
Search this Thread
 
Old 05-12-2010 | 11:34 AM
  #1  
Thread Starter
Tech Regular
iTrader: (25)
 
Joined: May 2010
Posts: 415
From: Michigan
Default Cheap charger for 4s

Sorry for the noob post, but im new to lipos, and bought a buggy from someone on here with 4s 5000 batteries. Can anyone point me in the direction of a good/inexpensive charger than can charge these batteries at 5a?

Thanks
GaRsNoW is offline  
Old 05-12-2010 | 12:02 PM
  #2  
Tech Elite
iTrader: (17)
 
Joined: Apr 2009
Posts: 3,055
Default

This one would work great for the packs you have.

If you might move up to 5s or 6s packs in the future then this one would be better.
burnineyes is offline  
Old 05-12-2010 | 12:08 PM
  #3  
Marzac2's Avatar
Tech Master
iTrader: (12)
 
Joined: Jan 2008
Posts: 1,046
From: Southern California
Default

+1 agree with first poster.
Marzac2 is offline  
Old 05-12-2010 | 01:07 PM
  #4  
Tech Lord
iTrader: (21)
 
Joined: Jul 2008
Posts: 11,530
From: Houston, TX
Default

Chargers are rated by output power. This output power sets what the charger can do as far as current at a give voltage (cell count). What fools a lot is that a 50watt charger is rated for up to 6S (22.2v nominal). What they don't tell you is the charger reduces charge rate to stay under its power limit and although the charger will charge that 6S, it will take literally hours to finish a charge.

If your 4S is a 5000, a 1C charge takes 84watts, so an 80watt charge will not let you do a full 1C (5amp) charge - 80/16.8 = 4.76a will be all the charge current allowed under its 80watt limit. This will increase charging time.

The GT Power (2nd link) is 200watts and would be powerful enough to do a full 1C charge rate. This is a DC charger and will need a separate power supply. I've been using mine since before last Xmas and its been a good charger.


There are some options with AC/DC chargers, but they're more expensive.
Duster_360 is offline  
Old 05-12-2010 | 01:39 PM
  #5  
Thread Starter
Tech Regular
iTrader: (25)
 
Joined: May 2010
Posts: 415
From: Michigan
Default

Originally Posted by Duster_360
Chargers are rated by output power. This output power sets what the charger can do as far as current at a give voltage (cell count). What fools a lot is that a 50watt charger is rated for up to 6S (22.2v nominal). What they don't tell you is the charger reduces charge rate to stay under its power limit and although the charger will charge that 6S, it will take literally hours to finish a charge.

If your 4S is a 5000, a 1C charge takes 84watts, so an 80watt charge will not let you do a full 1C (5amp) charge - 80/16.8 = 4.76a will be all the charge current allowed under its 80watt limit. This will increase charging time.

The GT Power (2nd link) is 200watts and would be powerful enough to do a full 1C charge rate. This is a DC charger and will need a separate power supply. I've been using mine since before last Xmas and its been a good charger.


There are some options with AC/DC chargers, but they're more expensive.

Ok, great! Thanks everyone for your input. I'll order teh GT power so I dont shoot myself in the foot in the long run.

Will any power supply work? Like from a laptop? If not, any specific one I should get from hc.com?
Like this one from HC.com?

I cant post links, but this is the title of it
IMAX Power Supply 100~240v 5A

Last edited by GaRsNoW; 05-12-2010 at 02:50 PM.
GaRsNoW is offline  
Old 05-12-2010 | 02:54 PM
  #6  
el_Fernando's Avatar
Tech Regular
iTrader: (6)
 
Joined: Dec 2009
Posts: 421
From: Yay Area
Default

Originally Posted by Duster_360
Chargers are rated by output power. This output power sets what the charger can do as far as current at a give voltage (cell count). What fools a lot is that a 50watt charger is rated for up to 6S (22.2v nominal). What they don't tell you is the charger reduces charge rate to stay under its power limit and although the charger will charge that 6S, it will take literally hours to finish a charge.

If your 4S is a 5000, a 1C charge takes 84watts, so an 80watt charge will not let you do a full 1C (5amp) charge - 80/16.8 = 4.76a will be all the charge current allowed under its 80watt limit. This will increase charging time.

The GT Power (2nd link) is 200watts and would be powerful enough to do a full 1C charge rate. This is a DC charger and will need a separate power supply. I've been using mine since before last Xmas and its been a good charger.


There are some options with AC/DC chargers, but they're more expensive.
Duster_360 you are the GURU of RCtech dude You are always on point man.
el_Fernando is offline  
Old 05-12-2010 | 04:41 PM
  #7  
Tech Lord
iTrader: (21)
 
Joined: Jul 2008
Posts: 11,530
From: Houston, TX
Default

Originally Posted by GaRsNoW
Ok, great! Thanks everyone for your input. I'll order teh GT power so I dont shoot myself in the foot in the long run.

Will any power supply work? Like from a laptop? If not, any specific one I should get from hc.com?
Like this one from HC.com?

I cant post links, but this is the title of it
IMAX Power Supply 100~240v 5A
Yes, any power supply will work - but will only run the charger to the power level that the supply provides and thats only 60watts. Charging a 4S with that supply even using the GT Power Charger, you'd be current limited again and looking at long charge times.

To run the GT Power Charger at max power, you need 220 watts or so (chargers have some inefficiency), so if the supply is 12v, you'd need 18.3 amps. Practicallyspeaking, you'd need a 20amp supply. HC has one that would do, but the cost of shipping something as heavy as a big power supply is not what you want to do. This would run it at full power -

http://www.amainhobbies.com/product_...-138V-20A-260W


This would also run it, it wouldn't be at full power, but would be more than enough to charge 4S at full 1C charge rate -

http://www.amainhobbies.com/product_...-138V-10A-130W




Originally Posted by el_Fernando
Duster_360 you are the GURU of RCtech dude You are always on point man.

Thanks dude!!
Duster_360 is offline  
Old 05-12-2010 | 05:23 PM
  #8  
Tech Elite
iTrader: (17)
 
Joined: Apr 2009
Posts: 3,055
Default

Good catch Duster! I rarely charge faster than 0.5C, so I forget that everyone wants to charge at maximum capacity. The first link would cut back amperage once the batteries voltage peaked out. The 200W charger would be better anyways, it will allow you to move up easily when or if you are ready.
burnineyes is offline  
Old 05-12-2010 | 07:59 PM
  #9  
Thread Starter
Tech Regular
iTrader: (25)
 
Joined: May 2010
Posts: 415
From: Michigan
Default

Ok, im going with the first charger, Turnigy MAX80W 7A Lithium Polymer Battery Charger, as I dont really see myself going to 6s. What power supply should I get?
GaRsNoW is offline  
Old 05-12-2010 | 08:21 PM
  #10  
Tech Lord
iTrader: (21)
 
Joined: Jul 2008
Posts: 11,530
From: Houston, TX
Default

Wait til this comes back in stock -

http://www.amainhobbies.com/product_...-138V-10A-130W

Or this (but its going to be expensive to ship) -

http://www.hobbycity.com/hobbycity/s...100~240V_12.5A
Duster_360 is offline  
Old 05-12-2010 | 08:32 PM
  #11  
Thread Starter
Tech Regular
iTrader: (25)
 
Joined: May 2010
Posts: 415
From: Michigan
Default

Thanks duster for all your help.

I'm really torn on what to do right now. I dont want to shoot myself in the foot incase I go 6s down the road... If I go with the smaller charger and the power supply from hc.com, will I charge a 5000 25c 6s fine? Will it just take longer?
GaRsNoW is offline  
Old 05-13-2010 | 03:56 AM
  #12  
Tech Lord
iTrader: (21)
 
Joined: Jul 2008
Posts: 11,530
From: Houston, TX
Default

Yes, it will charge the 6S just fine. It will just take longer since the 6S at 1C requires more charger output power than the 80watt charger can supply.

Thats puts you into that current limiting mode which basically means instead of charging at 5amps, you'll be charging at 3.1amps.
Duster_360 is offline  
Old 05-27-2010 | 07:39 AM
  #13  
Thread Starter
Tech Regular
iTrader: (25)
 
Joined: May 2010
Posts: 415
From: Michigan
Default

hey duster quick q,
I ordered the charger from hk like you suggested_ I'm wondering if you know if it comes with a us adapter? If not do I just get one from radioshack?
GaRsNoW is offline  
Old 05-27-2010 | 08:08 AM
  #14  
Tech Lord
iTrader: (21)
 
Joined: Jul 2008
Posts: 11,530
From: Houston, TX
Default

The GT Power charger? If thats the one, mine came with the USB cable, but when I bought mine it was $70 and I don't know if they've dropped some of what it used to come with to get the price down or not. The ad still shows a cable, so I'd expect to find one when it arrives.
Duster_360 is offline  
Old 05-27-2010 | 08:16 AM
  #15  
Thread Starter
Tech Regular
iTrader: (25)
 
Joined: May 2010
Posts: 415
From: Michigan
Default

yes I bought the gt power. What do you plug your usb cable into?
GaRsNoW is offline  


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.