Discharged battery level question

[Duclover]

I've purchased two Losi 5000 mah lipos and have run them for 6 runs now and have noticed that when I hook up to the charger (Hyperion ac/dc 1 port 0606i) my voltage levels are higher than before. They were originally coming in for fuel and showing 6.6-6.8 volts (Oh I forgot to state that Im running 2-2s lipos) and the last 3 runs show 7.1-7.3 volts left in the batts. I have set the stock esc using the programing module to low cutoff and low timing consistently. Any ideas as to why the voltage has changed so from a matter of 10-15 runs ago? I'm thinking the esc is finally going gooey.

Thanks as always,
Duc

[sn00p]

When you set the ESC voltage cutoff this works whilst the batteries are under load. they cutoff say at 3 or 3.5v per cell and then by the time you get them on charge they have recovered and you will end up with a higher Voltage than the cutoff like 3.8v or sommin. So you could be charging after a longer recovery period or its the fact your batteries have now settled in, they take a few charges/cycles to get themselves aligned and gain good charge/discharge rates. Im guessing after a few cycles they are now recovering much better than when you 1st bought them.

[Ub Hauled]

it could be that you are using less mAh due to a change on the setup... have you changed anything on your setup?

[kookie_guy]

correct me if I'm wrong, but aren't you supposed to be using high cutoff for lipos?

[Ub Hauled]

correct me if I'm wrong, but aren't you supposed to be using high cutoff for lipos?

While you charging lipos they will go up to 8.40 (on 2s packs)
they are 7.4v is nominal, but at the end of the charge they are 1v higher.
The chargers usually have a max voltage set for each amount of cells...
If your charger does not have that, please make sure that you do not charger
over 8.4v on the 2s packs.

[kookie_guy]

While you charging lipos they will go up to 8.40 (on 2s packs)
they are 7.4v is nominal, but at the end of the charge they are 1v higher.
The chargers usually have a max voltage set for each amount of cells...
If your charger does not have that, please make sure that you do not charger
over 8.4v on the 2s packs.

ummmmmmmm, huh????

I was referring to his statement that he programmed the stock ESC for low cutoff and high timing, but he is running lipos. I was under the impression that you gotta set high cutoff for lipos.

[sn00p]

Yes you should set to high cutoff on lipos...

[Duclover]

it could be that you are using less mAh due to a change on the setup... have you changed anything on your setup?

All right, after a few more runs my original question is still out there but I need to letcha know what the set up is for those runs. I've had the esc set to low voltage cutoff (and still coming in after my runs with 7.1-7.3 volts left before charging), Lipo (ofc) and high timing as i've been told that the stock motor is a 6 pole motor so we're supposed to be aight there. Also, I'm charging with a Hyperion 0606i with the 8.4v cutoff so we're safe there.

I'm still thinking that the esc has something to do with not only the voltage question but the runs themselves as one of the "capacitors/diodes" or whatever they are is protruding out about 1/4" from being flush with the aluminum. I've got a 100 amp ordered and look forward to seeing if that has any impact.

So, as per Sn00p's last thread I have programmed the esc for high voltage cut off but seeing as the low cut ff was bringing me in with 7.1-7.3v I don't see that as being an issue....correct me if I'm wrong?

[Ub Hauled]

wait a sec... you have a high voltage cutoff on the ESC!? I have never heard of that...
all you need to set (as far as cutoff) is the LOW, so the lipos don't over discharge...
usually in the range of 3.3v or 3.4v per cell.

[sn00p]

for lipos set the cuttoff to HIGH........... it says in the instructions...

http://www.proboatmodels.com/ProdInfo/Files/PRB3309BL-Waterproof-ESC-ManualLoRes.pdf

http://www.proboatmodels.com/ProdInf...ing_Module.pdf


Cutoff Voltage
In High Cutoff mode, the cutoff voltage
is automatically set to .9 volts per cell.
Li-Po will cut off at 3.0 volts per cell.
In Low Cutoff mode, the cutoff voltage
is automatically set to .7 volts per cell.
Li-Po will cut off at 2.7 volts per cell.
The High Cutoff mode allows ample power
in reserve for return to shore but may limit
runtimes.
The Low Cutoff mode allows longer
runtimes but leaves less battery power in
reserve after cut off for returning the boat
to shore.

[sn00p]

I would like to point out here as well..... when connecting up the card you need the power switch switched on and batteries NOT connected. THEN connect card and whilst leaving everything switched ON connect the batteries. wait for bleep and then the esc arming beeps to follow. ONLY then are your settings set. the instructions are a little vague around this but i founf this was the way to do it.

[Duclover]

I would like to point out here as well..... when connecting up the card you need the power switch switched on and batteries NOT connected. THEN connect card and whilst leaving everything switched ON connect the batteries. wait for bleep and then the esc arming beeps to follow. ONLY then are your settings set. the instructions are a little vague around this but i founf this was the way to do it.

As always thanks Sn00p. I have read and reread and reread the directions (and you're right they're not very detailed) which is why I wanted to know why my voltage seems high even with the low cutoff selected after programming the esc properly. So long as I'm not damaging anything or doing anything wrong its all good and simply a learning experience.

And yes UB....the programming module for the stock esc does offer both the low and high cutoff. After reading many of your threads I'm sure you're aware of it but probably moved on to after market some time ago and simply forgot. Thanks for everything.

Duc