Charging rates and times

[helijohn]

i think it may be user error lol

Could be!

I use them just before I put the battery in so as to make sure I have got a charged battery in my hands.

[Grumpy]

The little cheap plug in balance port ones are great for a spot check if the lipo is full or not. How accurate they are im not sure but serve a quick test of full or not well.

Yep, I'd not be without mine. due to their elusive nature I need at least four to be sure I can find one when I want one, but at £2 or less each that's not a big deal. They arent ever intended to be precision measuring instruments, you should use a quality multimeter for that, but as a quick voltage check in the field they are IMHO indespensable.

I actually managed to flush out a third one of the (at least) four I own. it had gone into hiding in the inside pocket of the case i store my Tx in Anyway, it too was within one hundredth on a volt accuracy compared to my digital . in percentage terms that a voltage accuracy of one quarter of one percent based on a 4.2v cell. I'd call that pretty flipin accurate for the intended purpose.

[helijohn]

it too was within one hundredth on a volt accuracy compared to my digital . in percentage terms that a voltage accuracy of one quarter of one percent based on a 4.2v cell. I'd call that pretty flipin accurate for the intended purpose.

You must have better quality than mine!

[SaneAdam]

Could be!

I use them just before I put the battery in so as to make sure I have got a charged battery in my hands.

That is an appropriate time to use them for sure. Always good to be sure you have a charged pack. So… for the purposes you are using them for it should be fine shouldn't it? When you say wildly inaccurate… are you finding as you check your packs before flight they have a very low reading? Packs will rise a few per cent when cooled…. but they will also lose a few as they are left charged for a few days.

I do the same as you and double check my packs are charged. Sometimes they will say 98%. But i know that is a charged pack. Just because it has lost 2% doesn't concern me.

So are you getting silly low readings? As i say… it is good to connect, disconnect then reconnect a few times just to make sure you are getting an accurate reading. I often misalign the pins slightly which gives odd readings. You may have just had a few of those situations

[helimadness]

Yep, I'd not be without mine. due to their elusive nature I need at least four to be sure I can find one when I want one, but at £2 or less each that's not a big deal. They arent ever intended to be precision measuring instruments, you should use a quality multimeter for that, but as a quick voltage check in the field they are IMHO indespensable.

I actually managed to flush out a third one of the (at least) four I own. it had gone into diding in the inside pocket of the case i store my Tx in Anyway, it too was within one hundredth on a volt accuracy compared to my digital . in percentage terms that a voltage accuracy of one quarter of one percent based on a 4.2v cell. I'd call that pretty flipin accurate for the intended purpose.

I left on in my pocket and my wife put it through the wash. Some of the pins got a bit bent but dried out and still worked fine :-)

As for being inaccurate. I found with a charged 6s pack some of them wont recognize the correct full voltage. And when it goes through the cells it gets to cell 6 and give a totally crazy reading. I think must be over the max voltage it will register or something. After the flight and the voltage is lower they read fine on all 6 cells. IT is more than enough to tell me the pack is fully charged but.

Perfect little things.

[helijohn]

it too was within one hundredth on a volt accuracy compared to my digital . in percentage terms that a voltage accuracy of one quarter of one percent based on a 4.2v cell. I'd call that pretty flipin accurate for the intended purpose.

So I just checked a battery that was reading 4.2v on the icharger and the little gizmo ranged from 4.15 to 4.22. Here's the problem, in fact that was the third attempt, first and second time it registered some sort of square symbol and a weird low number on one cell. I almost thought a cell was dead.

[Grumpy]

Even an error of 5 hundredths of a volt is good enough for a quick capacity check in the field. FWIW the LiPo checkers i have are the ones with the built in alarm, like this: 1-8S Checker Tester LED Lipo Battery Voltage Indicator Buzzer Alarm Low Voltage | eBay

And also one of the Hobbyking ones with the built in USB charger: Hobbyking 2~6S Lipo to USB Charging Adapter and Cell Checker (UK Warehouse)

They are all within 0.01v against my digital multimeter. The USB charger version is especially useful, great for charging up your phone.

[helijohn]

At the farm today I checked the batteries with my cheapo checker, one reading was 4.15 on one cell and 4.24 on another.

[Grumpy]

At the farm today I checked the batteries with my cheapo checker, one reading was 4.15 on one cell and 4.24 on another.

So if the actual voltage was 4.2 then that's a maximum of 0.05v error (five hundredths of a volt). That's a 1% error on 4.2v

Easily good enough for a quick capacity check in the field, but you could probably get better results from a different checker based on the accuracy of the ones i have (0.01v).