Lipo over-voltage

[LaunchPad]

Hi all, I'm new to the world of electrics as well as heli's (previously fixed wing nitros) and I'm still in the process of putting together my Trex 450 Sport. I bought a brand new 3S 45C 11.1V ThunderPower Pro Power lipo from fast-lad which I havent got round to charging yet as the heli is still in construction. I did however check the voltage on the battery which measured 16.1V. No doubt I was slightly concerned about this, Is this normal or is this showing a higher voltage due to the battery not being under load.

Thanks in advance.

[SRH990]

Something is definitely wrong, a 3 cell lipo shouldn't be more than 12.6v fully charged, fresh off the charger. Are you sure you haven't got a 4 cell pack? A 4 cell pack would be 16.8v fully charged and around 15.4v at delivery/storage charge.

How are you measuring the pack voltage? Are you sure your voltmeter is accurate? If you'd managed to get a 3 cell pack up to 16.1v, even with no load on it, it would most likely catch fire.

[LaunchPad]

Thanks for the reply SRH990. After you mentioned that I went and checked my laptop supply voltage with the same multimeter which was showing 4 volts over the stated rating. I guess it time to get a new multimeter and to learn not to just trust your tools I feel better know that the battery is not the one at fault.

[trident3]

The best way to measure the status of an RC heli lipo battery is with a tester designed to measure the individual cell voltages and overall condition of LiPO batteries. I use an Align multi-function tester Multi-function Tester RCE-MT8 K10402TA-1 - Accessories - Align-Trex.co.uk, Specialist supplier of kits and spares for R/C Align Helicopters which also includes a servo tester.

There are many different makes of LiPO battery testers but I do think that anyone flying electric helis should have one.

I always briefly check a battery before using it, it takes just a few seconds. Doing so recently saved me from using a battery I thought was charged but wasn't - which may have resulted in a crash and certainly would have done the battery no good at all.

T3

[coptermanic]

Buy yourself a decent LiPo charger, as it will look after the charging and protect your cells, and ultimately prolong the life of your batteries. There are many on the market, but for around £50 to £60, you can pick up a good dual voltage AC/DC type.

[LaunchPad]

I think I need to replace my multimeter but that Multi-function Tester looks brilliant. I like the fact its a servo tester as well. Thanks T3.

[LaunchPad]

I landed up buying a Hyperion EOS 0720i NET3 AD, 1S-7S from fast-lad. Main reason I got this was ThunderPower never guarenteed the 6C charge rate of their Pro Power battery without this charger. Still might go into this very cautiosly and start off at 1C

[Mutley]

I bought a brand new 3S 45C 11.1V ThunderPower Pro Power lipo from fast-lad

Just for ref and to drop back a step: 45C is overkill, 20C/25C i've found is more than adequate even with an upgraded motor in the sport.

[coptermanic]

I landed up buying a Hyperion EOS 0720i NET3 AD, 1S-7S from fast-lad. Main reason I got this was ThunderPower never guarenteed the 6C charge rate of their Pro Power battery without this charger. Still might go into this very cautiosly and start off at 1C

It's best to do your charging at 1C anyway. No need for a big battery as 20 to 30C is ample for most flying, 3D apart!! ThunderPower are not great value for money either. Better off buying either Turnigy [from HobbyCity] or the new LoongMax Tipples [ Conceptcopters, Robotbirds], both are good brands and better value.

[LaunchPad]

I figured it might be, I'll need to get another battery (or two..) soon so I'll have a look at a lesser rating then

[Planehazza]

Another vote for loong max. Half the price, just as good