Charger Power Supply

[HeliDan]

Hi
Any one make a decent 120VAC to 12VDC power supply to operate a LiPo charger from?

thanx

[jrohland]

I posted replies to this (http://www.helifreak.com/viewtopic.php?t=23069) thread which may help you.

As always, the answer is it depends. What is your budget? How much current does it need to supply? How portable would you like it to be?

Assuming you need to charge 3 cell packs at a maximum of 6.2 amps, a 20 amp unit should do fine. Go on Ebay or other pricing services and search for dc power supply 20 amp. You should find a number of good quality units for around $50US. Don't be concerned if they rate their dc volts at 13.x. Most LiPo chargers can take input voltage up to about 15. The good quality, reasonably priced units are sold for HAM radio hobbist. These are excelent for LiPo charger use.

If you want to charge larger and/or more packs you may need more amps. If you want a field charger, Sears, Wallmart and others have portable jump start units with a 20AH, deep cell battery and a built in charger. Those can be used at home and the field if the built in charger is fast enough.

Let us know more about your needs and we may be able to give a more specific answer.

jrohland

[HeliDan]

OK. I can look on EBAY. I looked at the TP website after my post.

I would be charging a 11.1V TP2100 (3cell) for a TREX-450 heli. So, the five amp PS sold my TP should do fine, right? only $30 bucks. or is that a mistake?

Thanx

[jrohland]

Arguments rage about how fast you can charge your packs.

Charlie Wang of Thunder Power apparently did extensive testing and found that for specified TP packs, it is completely safe to charge them at up to 3C IF you have a TP-1010C charger AND a TP-205 or TP-210 balancer all properly connected. To charge 3 cell 2100MAH TP packs at 3C requires about 6.2 amps.

If you are only ever going to use 3 cell packs and, you don't plan to charge more than one at a time, a 5 amp power supply will be just OK. However, you state that power supply is about $30US. For about the same price, you can get a much higher amp power supply. I would look for a 10 to 20 amp supply in that same price range. I believe you will find one.

jrohland

[HeliDan]

OK. I will look around. Based upon your answer, sounds like the charger is capable of charging more than one battery at a time. Although I do not know how the system works yet, does that mean I need one charger and a separate balancer for each pack I am charging if charging more than one at a time. Unless I am mistaken, I have heard that it is smart to balance all the time. I interpret this as connecting the balancer to the charger then the battery to the balancer. The balancer then acts as the safety device for each individual cell.

Please let me know if I am wrong.

thanx!

[jrohland]

...Based upon your answer, sounds like the charger is capable of charging more than one battery at a time...Actually, I tried to be careful about that very issue. The power supply can provide power for one or more chargers. A charger can charge ONLY ONE battery pack at a time.

It is extremely important for the charger to get feedback from the pack during the charge. Anything modifying that feedback--such as an extra battery pack--could cause the charger to get confused.

So, bottom line is:
A DC power supply can power as many chargers as you wish as long as it has enough amperage.

The charger can charge only one battery pack at a time unless it is designed to do more. For example, this (http://www2.towerhobbies.com/cgi-bin/wti0006p?&T=4&I=GPMM3015) one can do 4 at a time.

The balancer can balance one pack at a time. I have never seen a multi-pack balancer but, they might exist.

[HeliDan]

Thats what I thought. Now, you use th balancer while charging right? not after like some have alluded to?

Thanx!

[jrohland]

...Now, you use th balancer while charging right? not after like some have alluded to?...
Balance and charge at the same time is a good idea. I connect both and charge while balancing all the time.

jrohland

[WillJames]

I personally would NOT charge much higher than 1C for maximum longevity of your packs.

If you can't balance while charging, then balance after flying and before charging.

If you don't have the 1010/210V FlightPower makes a V-Balance Module that will work with any Li-Po compatible charger that works very well.

[spork]

Also, many people use the power supply from an old PC. At least around here you could get 10 of those for free by this afternoon. Looks like you're in Hayward. Should be the same for you.