Hyperion Charging question - mAh reading after charge

[JThiessen]

I've always been under the impression that charging is a matter of getting the voltage up to a packs maximum voltage. However, recent experiences with others have led me to think that maybe getting the mAh up is just as important. I've seen people recharge their packs until the charger showed that the mah were up to the rated capacity of the pack.
So that led to me actually paying attention to what my Hyperion Duo reads after the charge.
On my A123's, its been hit or miss. Sometimes it shows numbers between 4000 and 4600, but more often than not, they read about 1900-2100.
Today, with my first set of Lipos (Zippy 3S 4300's) that i purchased used from a member on here, they charged up to correct voltage, but they only read about 2K mAh, and 20 and 21 Ohms.
Should I be concerned?

I also attempted to sync charge the packs, the instructions state that you hold the enter and the down button to get sync mode, but it did nothing. Any tips on that?

[SpEEdyBL]

Whoever you have been listening to is wrong.

First, Lipo packs always come ~50% charged for safety reasons. I would be more concerned if your pack took its full 4300 mah on the first charge.

Whatever you do, NEVER let a lipo cell go higher than 4.25 volts. A lipo cell is considered fully charged when it rests at 4.2 volts, no matter what basically and this is why the charger reduces the current, while keeping the cells at 4.2 volts, until the amp rate is zero. If you try to put more mah into the pack after that, the voltage will rise and that is a complete no no.

Sorry for the tone of this post, but you are seriously asking for trouble if you try do what you were mentioning.

I don't know why your A123s are only half charging some of the time, but do you run them down all the way?

[JThiessen]

I dont think I said anything about trying to get the voltage any higher - I wanted to know about the amperage. I think maybe I misstated what I wanted to know. I'm not going to try to re-charge them to get the mAh's up, I just wanted to know the rationale behind the numbers I'm seeing, if it was a sign of a dying pack, and if what I was watching others do was wrong (BTW, they were doing this on Nimh packs).

The lipo's I was charging today were purchased used and were at 3.6V prior to charge, 4.2 after. What does the 2100mah number my charger is reading after the charge mean? It also shows me the charge rate.

The A123's are charging to full voltage, its just the mah reading that is "low".

[tc3_racer_001]

when i hit my cutoff for zippy 4800's i can only put around 3300 back in. (3.2v cutoff)

so im not sure how they get their 4800mah rating?

[rootar]

Originally Posted by tc3_racer_001

when i hit my cutoff for zippy 4800's i can only put around 3300 back in. (3.2v cutoff)

so im not sure how they get their 4800mah rating?

huh maybe the zippys arent all that and a bag of chips. because if they rate a pack for 4800 and it only holds 3300-3500mah after you dump it then that in my opinion is a 3500 pack because thats the usable amount of capacity it has right? i know when i dump my protek 5s4000s (20 minute main) they read 15.5 volts going on the charger and hold 4100 mah and 21 volts

so im getting a full 4100 mah of capacity out of my 4000 5s lipos and your getting 3300-3500 mah of capacity out of your 4800s???????? that sounds bad

[JThiessen]

Rootar, I think you are looking at it backwards. My original question was what is the meaning of the mah reading the charger gives at the end of a charge. It was answered that it is the amount that was "put back in", not the total capacitiy of the pack.

[suicideneil]

Originally Posted by rootar

huh maybe the zippys arent all that and a bag of chips. because if they rate a pack for 4800 and it only holds 3300-3500mah after you dump it then that in my opinion is a 3500 pack because thats the usable amount of capacity it has right? i know when i dump my protek 5s4000s (20 minute main) they read 15.5 volts going on the charger and hold 4100 mah and 21 volts

so im getting a full 4100 mah of capacity out of my 4000 5s lipos and your getting 3300-3500 mah of capacity out of your 4800s???????? that sounds bad

That logic is somewhat flawed; if you were to drain a lipo down to 0amps, then recharge it back upto 4.2v, it would more than likely say on the charger that you have pumped in the full rated capcity. Saddly your lipos would also be dead as you cant discharge then down below about 2.6v per cell; that is where you are 'loosing' some of total capacity- there is a difference between rated mah and usable mah quantities.

With my 2300mah A123 packs, I usually pump back in about 2000mah (I run them in the truck till they dump). With my 4000mah lipos, I usally put about 3000mah back into them- you cant drain a battery and refill it like a nitro fuel tank, you have to leave some energy in there to prevent the voltage from dropping too low and killing the pack.

I'd love to explain the difference observed between the Protech and Zippy lipos, but the only thing I can think of is that the Protechs actually hold somewhat more mah than they are rated at, and that the LVC is set a bit high for the Zippies...

[Arct1k]

Also remember that the balancer draws some mah in balancing the cells so not all is going into the battery.

I just check the mah post charge to ensure I didn't drain the pack too much... I never really every run up to the lipo cutoff as you can "feel" that the car is slowing down and not giving its best. I normally stop at this point...

TC3 they get that rating by running it all the way to 2.7 or even maybe 2.5...

[BrianG]

Maybe the cutoff is a bit high? I like to set the LVC such that the lipos are at ~3.5v/cell once disconnected and let sit for a few minutes.

[Gee]

I have wondered the same thing Jeff. I use the sb989 and have used it for nihm and lipos for over a year. I've never seen the mah reading on the charger to be close to what the pack is capable of. Really stopped paying attention to that part since I don't know what it is telling me. I pay attention to the volts but haven't understood what the mah reading on the charger after the battery is done charging.

For example I just got done charging a FP 4s 5000 lipo that wasn't used much last time so just topped it off. The charger has 16.77volt and 1468mah on the display. Is it telling me that out of 5000mah only 1468mah was used last time/or it took 1468mah to "refill" the lipo up to the 5000 again?

[JThiessen]

Originally Posted by Gee

For example I just got done charging a FP 4s 5000 lipo that wasn't used much last time so just topped it off. The charger has 16.77volt and 1468mah on the display. Is it telling me that out of 5000mah only 1468mah was used last time/or it took 1468mah to "refill" the lipo up to the 5000 again?

Thats exactly what I was wondering. Its showing data, but what the heck does that data mean.

BTW, I ran those two packs for the first time this afternoon for about 2 minutes before the rain came. This was my first ever run with lipo, and one of the few runs I've had with the MMM/1515 2.5D. HOLY @(@(@!!! I ran them in 6S config, and was relatively easy on the throttle - but still more power than the new Badlands could hold on the dry pavement - even at @35mph. I'm really going to have to get better at driving, or I'd better just stick to Nimh and A123.....

I just check the mah post charge to ensure I didn't drain the pack too much

So can I interpret what you are saying to mean that the value my charger is showing for mAh AFTER the charge is complete is the amount of mAh that have been put back in, not the total that is put back in?

[Arct1k]

I believe it to be a measure of how much "energy" it has put back in the battery - simple calc of amps on charger and time...

[E-Revonut]

Originally Posted by Arct1k

I believe it to be a measure of how much "energy" it has put back in the battery - simple calc of amps on charger and time...

This is correct! I have the duo charger and had another hyperion before that. The mah displayed is what the charger put back into the pack. Also as Arct1k had said a few posts back the balancer drains some mah to keep things in balance. So if you have a 4000mah pack that you run to the lvc it could very well take 4100-4400mah back into it, that would just mean that the cells where slightly out of balance during charging and it drained some off one cell. Thats something I've tried explaining to a few on here before but the insist that there zippys have 500mah more capacity than what they are rated at! Sorry for the rant!

[JThiessen]

That makes perfect sense to me.
E-Revonut
Since you have the duo, have you tried to sync charge? I attempted it the other day, but it didnt seem to function (charager just gave that blank stare......)!

[E-Revonut]

You have to set up both channel 1 + 2 for the proper setups, press and hold enter and it will say solo and then I beleive you press up or down to select sync. Then hold enter to start charging. I have used it to sync charge 2 3s packs and it worked flawlessly. I will say that the Hyperion chargers are great but their instruction manuals suck! I read my manual through and had a hard time getting it set up to do anything! Next time I just played around with it and it and now I understand how it works much better