Should I discharge the Battery?

[BillB]

I am the recent proud owner of a Robonova. Everything works fine and the battery allows impressivey long playtime.

I have a quick question about charging that hopefully someone can help me with:

Before a charge should I be discharging the Robonova battery with the yellow discharge button on the charger? Will it cause any permanent damage if I charge a half full battery without wearing the battery down?

Thanks in advance

[bauermech]

Before a charge should I be discharging the Robonova battery with the yellow discharge button on the charger? Will it cause any permanent damage if I charge a half full battery without wearing the battery down?

Hi BillB,

Congradulations on your new RN-1!

Ni-Cad's build "memory" overtime - after charging a battery that has not been fully discharged from use. The effects are not immediate nor are they what you'd call permanent. It will begin to apear that your charge isn't holding for nearly as long. So to answer your question, you don't have to discharge before every charge cycle... just every so often to help keep the battery at its peak performance.

[bauermech]

Ni-Cad's build "memory" overtime - after charging a battery that has not been fully discharged from use.

I should probably clarify what I meant by "fully discharged". As subpilot pointed out, you don't want to run your batteries down to the point where your robot falls from lack of power... that's actually a good sign that it's too late and will begin to permanently damage the cells and/or reverse their polarity if drained too far.

[bauermech]

Sorry if I'm becomming annoying but here's a link to just about everything you'd ever want to know about Robonova batteries... just in case I forgot something important.

[CaptKill4Fun]

Before a charge should I be discharging the Robonova battery with the yellow discharge button on the charger? Will it cause any permanent damage if I charge a half full battery without wearing the battery down?
...

Hi BillB,

Congradulations on your new RN-1!

Ni-Cad's build "memory" overtime - after charging a battery that has not been fully discharged from use. The effects are not immediate nor are they what you'd call permanent. It will begin to apear that your charge isn't holding for nearly as long. So to answer your question, you don't have to discharge before every charge cycle... just every so often to help keep the battery at its peak performance.

Hi,

Matt ... you're forgetting the RoboNova-1 uses NiMH not NiCAD ... big difference and so you DO NOT have to discharge the battery before charging because NiMH do not build memory ...

When the bot gets low ... just plug it in and leave it until the charger wall-wart has a green LED showing full charge ...

However, like Matt said, don't let the batteries wear down so much they get destroyed ... if the bot starts to slag ... check it out & charge ...

BTW, I suggest if you switch to Lithium type batteries spend the few extra bucks and get a really good Lithium charger ... it may save your house from burning down! Personally, I suggest eithr the Great Planes Triton or my favorite the Thunder-Power TP-1010C SuperCharger with balancer ...

[BillB]

Thanks for all your advice - and the very quick responses.

Time to charge RN-1 ready for an action packed kung fu cartwheeling weekend.

[hivemind]

Also, if you are going to get a lithium batery, you will most likely need a regulator (unless you want to run at 7.4v) and you may want a circuit with an LED to ensure that the lithium doesnt run too low, otherwise it will also be toast. While running a lithium it would be hard to tell because they dont slow down like the NiMH or NiCAD batteries. But thats a good thing

[CaptKill4Fun]

Also, if you are going to get a lithium batery, you will most likely need a regulator (unless you want to run at 7.4v) and you may want a circuit with an LED to ensure that the lithium doesnt run too low, otherwise it will also be toast. While running a lithium it would be hard to tell because they dont slow down like the NiMH or NiCAD batteries. But thats a good thing

Hi,

Ignore "hivemind" ... the Low-Voltage LED is the blue LED in the head of your robot as you can read on page 95 in the RoboNova-1 manual ... and republished on Matt Bauer's web page ...

I haven't built the circuit described on page 95 of the manual, but my LED does blink when my battery gets low ... maybe the low-voltage circuit exists in newer bots, I don't know ... you can email service@hitecrcd.com on this question ...

Whenever I turn the RoboNova-1 OFF, I just plug the charger into my bot , so the next time I turn it ON the RoboNova-1 will be fully charged.

[hivemind]

I believe the low-voltage regulator has been included only in the newer models of the RN-1, as mine stock, and still now, does not have one, my ports are busy anyway though.

But if you were to use the low-voltage resistors and the stock template program it still would not work, the stock battery is 6v and probably will not be damaged by dropping a little bit, where a 2-cell lithium battery is 7.4 and needs to remain relatively close to that voltage. THe stock template program (i could be off slightly here) triggers the blinking LED at 3v which is half of the battery. If a lithium got this low it would be cooked. You would need to change the program so it triggers closer to 6.9v or maybe a little higher, because you dont want to ruin the battery.

Granted I have kind of verged off the original topic, so i apologize, but if you are feeling adventurous and want to switch to lithium which keeps a nice voltage thorughout use, and is what i will be switching to shortly, then hopefully this will help

[CaptKill4Fun]

Hi,

Actually, if anybody plans on using Lithium batteries LiPoly or LiIon it is much safer to use a real automatic Low-Voltage CutOFF switch ... this protects both the batteries from too much drain and also helps to prevent exploding batteries when you try to re-charge your damaged Lithium battery ...

My house and contents costs too much money to rely on a toy LED circuit when I can better protect it with a $25 part designed exactly for the job ...

#43355 - Duralite Low Voltage Cut Off PRICE: $24.95 USD
The Low Voltage cut off will turn the battery off at a safe 5.5 volts. Protects your battery.

5.5V LowVoltage CutOFFf (2.75V/cell) is the worst-case cutOFF when the operator isn't aware the batteries are running down ... a 5.5V cutOFF is still within the normal operational range of LiPoly/LiIon batteries ... however, the lower you take the batteries the faster they age ... and is why some users prefer 6V cutoff to get the most battery performance/$.

One thing to know ... millions upon millions of R/C hobbyists use these regulators in their cars, tanks, trucks, trains, helicopters and airplanes on NMiH's and LiPoly's ... If somebody finds something better please post a link in the forum so we can find it ...

BTW, I'm trying to get Duralite to manufacture a new combination Low Voltage CutOFF with a 6V Regulator for Lithium battery use in our bots ... I've specified two (JST type) inputs from the batteries and one output to the RoboNova-1 power connector ... so if you buy from Duralite ... please send a note to Jack Price and ask for that specific device ... I think they only need a few people calling and asking for it to get it out of the conference room and into production for the robotic world ...

[Bullit]

CAUTION!
Do not dischage a 7.4V lithium battery below 6V or the battery will be permanently damaged!!

I have many years of experience with lithium polymer batteries and I have lost many expensive batteries due to over discharging.

Batteries that are damaged are also prone to failure during charging. Which as stated above can cause a fire. There are many horror stories doccumented on r/c forums of people losing automobiles and homes due to fires that start by overcharging lithium polymer batteries.

Please be careful.

[Bullit]

Also, I would not trust my expensive lithium polymer batteries to a AtoD monitor subroutine running in robobasic. The robobasic template only monitors the battery voltage at idle not under load. This choice may be ok for NiMH batteries but for lithium polymer batteries I think it is unwise.

[Zembot]

Hey everyone,
I’m looking for a 6v cutoff that isn’t overly complicated to install. Will this work? I’m ready to give it a try. The price is right.

#43355 - Duralite Low Voltage Cut Off PRICE: $24.95 USD
The Low Voltage cut off will turn the battery off at a safe 5.5 volts. Protects your battery.

Is 5.5v actually too low for a 7.4 LiPo? If so, what would a Robosavvy recommend?

[hivemind]

I wouldnt do the 5.5v if i were you because you could damage the battery. I think that 6v is the right number to go with.

[rep001]

Voltage aside,what sort of amp draw are we looking at through a lipo saver as there are many available through the model shops and i have a box of them from electric flight use ? i am thinking in the ranges of 1-5amp maybe........