RunRyder - Charge or balance first ?

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Ace Hobby	.	Esprit Model	.	Thunder Power RC
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e-Electric Batteries & Chargers > Charge or balance first ?

nivlek
rrProfessor
Location: Norfolk England

I've got two brand new Thunder Power 11.1v 2100 packs , a Flight power balancer and an adapter lead to the TP packs . Do the packs need to be balanced before the first charge ?
I'm asking because I quickly plugged both packs in to the balancer , just to check that everything is working , and the balancer indicates that one pack is out of balance . I'm a little reluctant to balance this pack by further discharging what could be a virtually flat pack (how are lipo batteries supplied , flat or charged ?)

So , should I just charge tha pack as they are , balance them first , or partially charge them , then balance them and finally fully charge them .

At the end of the day , it gets dark .

03-16-2006 Over year old.

Pistol_Pete
Elite Veteran
Location: Tampa Bay non-Buccaneer

Confusing isn't it?

http://www.batteryuniversity.com/parttwo.htm

http://www.rcbatteryclinic.com/

A difference of over .05 between cells is considered unbalanced, othewise, no worries.

Never discharge below 3V under load, 3.6V resting PER CELL.

Never charge over 4.2V PER CELL.

A fully charged lipo will not read on the voltmeter the full amount.

Read directions that came with charger and contact manufacturer should you have any doubts.

<><>...the lunatic is in my head...<><>

03-16-2006 Over year old.

HOMEPAGE

Rob_T
Elite Veteran
Location: ..

Lipos are usually shipped at about 50% charge as thats optimal for storage.

I'd stick the battery right on charge with a balancer plugged in. I'm not a great fan of the standalone balancing method as it's balance at full charge that is most important. If the status light on the balancer flashes to indicate a large amount of unbalance, (check the instruction sheet that came with the balancer), then something is wrong- a new battery should not be that unbalanced!

Pete, I think you made a typing error- that should be 0.05V difference between cells for considering a battery unbalanced.

03-16-2006 Over year old.

Pistol_Pete
Elite Veteran
Location: Tampa Bay non-Buccaneer

Indeed...corrected....thanks.

<><>...the lunatic is in my head...<><>

03-17-2006 Over year old.

HOMEPAGE

Yug
rrProfessor
Location: UK. Herts

I'm plobraby doing it wrong, but I tend to balance before charging. Probably better to balance while charging, but I wonder weather the balancer could get in the way of the charging process.

03-17-2006 Over year old.

nivlek
rrProfessor
Location: Norfolk England

Quote
plobraby

That's a bit of a mouthful !

I was also concerned as to wether balancing while charging would cause a problem . The instructions seem to point to balancing the cells , then charging them while still connected to the balancer , so I guess either way must be fine . Both packs measure 11.7v off load , so balancing them first shouldn't overly discharge anything .

At the end of the day , it gets dark .

03-17-2006 Over year old.

Rob_T
Elite Veteran
Location: ..

The reason for balancing is to make sure that as the battery approaches fully charged, you dont have one cell get overcharged and get damaged, or worse start a fire!

Balancing a battery at anything other than full charge will then expose you to differences in the cell capacities as the battery approaches full. Suppose you have a 2 cell battery, where one cell is 1800mah and the other 2000mah, and you balance it while 50% charged. Then one cell will contain 900mah and the other 1000mah. Now charge it. After 900mah of charging one cell is full, but the other isn't so the charger will keep going.

This then leads to the smaller capacity cell getting damaged by overcharging, which will typically reduce its capacity, meaning the next time you do this, the difference between the cells will get larger

I used numbers above that represent a really bad battery- the cells should be much closer in capacity than that to start with, but I wanted to make the numbers easy. It does illustrate why I say that balancing at full charge is the most important step though.

03-17-2006 Over year old.

Yug
rrProfessor
Location: UK. Herts

Rob_T - I understand that. My concern is that if the balancer is connected during charging, could it not interfere with the intelligent charger logic and cause false extension or premature ending to the charging process ?

03-17-2006 Over year old.

Dr Lodge
Elite Veteran
Location: Guildford, Surrey - UK

A good balancer will work best whilst charging, since all its doing is ensuring the voltage between cells remains the same, it won't affect the total voltage across the pack which is what the charger sees.

Vibe 90, Vibe 50, Vigor CS x2,
Dyna-x, Knight 503D, Logo 10,
Trex 500, Mini Titan, Gaui EP200

03-18-2006 Over year old.

DOKEY
rrProfessor
Location: Northampton UK

I charge with the balancer plugged in at the same time.

Check the gallery!

03-18-2006 Over year old.

HOMEPAGE

nivlek
rrProfessor
Location: Norfolk England

Thanks for the input guys , I'll balance while charging .

At the end of the day , it gets dark .

03-18-2006 Over year old.

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e-Electric Batteries & Chargers > Charge or balance first ?

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