What amp and voltage to put LiPo battery into storage mode

[King Mustard]

I have a Voltz 5,000 mAh 4S LiPo battery and a SkyRC S65 (instruction manual) charger.

I have read lots of posts online about putting the battery into storage mode when I will not be using the battery for a while, but they tend to be based on different battery capacities to the one I have.

I can see the storage mode setting on the charger, but what amp and voltage numbers do I use to put the battery into storage mode?

I am a bit scared of the battery (all I see is scare stories about killing the battery by letting it be empty, or them exploding into fireballs), so just want to make sure I get the right settings.

 

[DavidB1126]

Amp, if you put it on for 5 amps it will only storage charge at around 1, or below 1 amp, if this discharging since the charger can only take in so much. If it's below the set voltage and it's charging the pack up to set voltage it will charge at the amperage you set. Storage charge voltage should be around 3.8v/cell to 3.9v/cell. So in total voltage it would be around 15.2v, for a 4S pack.

 

[King Mustard]

Amp, if you put it on for 5 amps it will only storage charge at around 1, or below 1 amp, if this discharging since the charger can only take in so much. If it's below the set voltage and it's charging the pack up to set voltage it will charge at the amperage you set. Storage charge voltage should be around 3.8v/cell to 3.9v/cell. So in total voltage it would be around 15.2v, for a 4S pack.

I do not have a voltage checker, unfortunately.

Before I put the battery into storage mode, does it need to be full? Empty? Any amount of charge?

 

[DavidB1126]

It can be any voltage between 3.2 and 4.2v/cell. Your charger should have a voltage meter already on it. What I personally do Is just set it for 5 amps and let it do its thing. It knows what the voltage is so if it's below the set voltage it will charge the battery up, if it's above the set voltage it will discharge the pack and bring the juice back into the charger. Note that discharging will take longer than charging.

 

[King Mustard]

It can be any voltage between 3.2 and 4.2v/cell. Your charger should have a voltage meter already on it. What I personally do Is just set it for 5 amps and let it do its thing. It knows what the voltage is so if it's below the set voltage it will charge the battery up, if it's above the set voltage it will discharge the pack and bring the juice back into the charger. Note that discharging will take longer than charging.

Thank you.

I went to the LiPo Storage section of the charger, it retained the 5A 14.8V from when I charge, and I just hit Enter.

This is what I am seeing:

I guess I just wait for it to beep to say it is done.

 

[thrak76]

Since you're discharging to get to storage voltage, it's going to take awhile with that charger. Nature of the charger.

 

[DavidB1126]

Yea it's discharging since it's above the set voltage and the charger can only take in .6 amps at a time which like I said it will take a bit of time to do. That's why I prefer to run down my batteries to about storage voltage and then put it on the charger

 

[King Mustard]

Since you're discharging to get to storage voltage, it's going to take awhile with that charger. Nature of the charger.

How can you tell it is discharging, rather than charging, to get it to storage voltage?

 

[DavidB1126]

How can you tell it is discharging, rather than charging, to get it to storage voltage?

Discharging - if voltage is going down (taken out of the battery)
Charging - if the voltage is going up (putting into the battery)

 

[thrak76]

You're pic shows voltage higher than storage voltage (~15.2V as @DavidB1126 stated), so it has to discharge. The capacity counter is what it has discharged. This style of charger does not have many features to show a ton of info, i have a similar style one.

 

[King Mustard]

The battery label states it is a 14.8V battery. Should I be concerned the charger is showing 15.76V in my photo above?

I presume the 185 meant 1.85v discharged so far?

 

[DavidB1126]

Not at all. 14.8 is just the nominal voltage of the lipo. Fully charged would be 16.8v and storage charge would be 15.2. Try not to go below 12.8v.

On the charger, assuming if the setup is like my T200, you can hit the status left/right buttons to go through the menus like individual cell voltage, "fuel" percent, and then other settings like temperature, end voltage and cutoff.

The 185 is the mah or current taken out of the battery.

 

[thrak76]

If you push the right arrow button on the charger, you can see the voltage of the individual cells. Just a little more information. Then you can push the enter button again to get back to the status display. You're looking for ~3.8V per cell.

 

[King Mustard]

If you push the right arrow button on the charger, you can see the voltage of the individual cells. Just a little more information. Then you can push the enter button again to get back to the status display. You're looking for ~3.8V per cell.

Ah, they are currently showing around 3.9v per cell.

Do I need to stop it myself when it reaches 3.8v per cell, or will the charger do it for me? (the manual confuses me)

 

[WickedFog]

but they tend to be based on different battery capacities to the one I have.

The 5000mAh is of course your capacity. It is how much energy the battery can store. Imagine mAh represents what size gas can you have. The higher the number, the more gas you can carry.

The C rating is how big the spout is that you pour the gas out of. The bigger the C rating, the faster you can pour the gas out.

The nominal and full voltage of the pack is determined by how many cells the pack has. Each standard LiPo cell is capable of dispensing 4.2v maximum at full charge. 3.85V is the nominal voltage of the pack.

You might think "how is 3.8v half (nominal) of 4.2v?"

It is because the useful range of a LiPo cell is 3.0v to 4.2v. Halfway between that range is exactly 3.85v. This is your nominal voltage. Anything more than .35v either side of that and you are damaging your LiPo, and the risk of fire goes up exponentially the farther you go past those values. So 3.0v to 4.2v is the LiPo cell's safe working range. Never go beyond that, especially over

When you put your LiPo on the charger, it knows if you need to charge the battery or drain it to reach your chosen storage voltage. So just plug it in, select storage mode, and make sure its set to 3.85v (3.8v-3.9v is fine).

Determining your charge amperage:
Your battery capacity is shown as mAh. You simply need to convert that to Amps instead of milliamps. So the Amperage you use should typically be whatever your mAh of your battery is divided by 1000.

Example:
1000mAh = 1 amp hour.
So take your 5000mAh rating, divide it by 1000.
5000mAh ÷ 1000 = 5A

That tells you that you should be charging at 5A to achieve a 1C charge rate. A 2C charge rate would be 5A x 2 = 10A. Racers typically charge at much higher rates to lower the internal resistance of their batteries, which will lessen voltage sag, and allow for a more consistant discharge rate. So you can charge at higher rates to get your battery charged faster. But doing so will likely shorten the lifespan of your battery. And some batteries cannot handle very high charge rates. Best to stick to 1C, or 2C if in a hurry, for every day use.

 

[King Mustard]

<snip>

When you put your LiPo on the charger, it knows if you need to charge the battery or drain it to reach your chosen storage voltage. So just plug it in, select storage mode, and make sure its set to 3.85v (3.8v-3.9v is fine).

<snip>

Before I hit Enter on the charger for storage mode, it had 5A 14.8V as the settings (presumably based on those settings being used when I last charged it).

Do you think those settings are fine, or should I stop the charger?

 

[thrak76]

It will stop on its' own when it reaches the set voltage for storage. Your settings are fine.

 

[King Mustard]

Thank you all, so much

 

[DavidB1126]

That's what we are here for

Well I'm here to have my daily laughs.

 

[WickedFog]

Before I hit Enter on the charger for storage mode, it had 5A 14.8V as the settings (presumably based on those settings being used when I last charged it).

Do you think those settings are fine, or should I stop the charger?

Yup. Should be fine.

LiPo battery voltages are listed at 3.7v per cell. This is their "listed" nominal voltage. This is because this is the average voltage a cell will typically deliver throughout the cycle of the pack. It starts off delivering 4.2v, but that quickly drops. It will then level off and deliver 3.7v for a bit, then gradually dip to your low voltage cuttoff set by your ESC, which should be set to 3.6v/cell or so. So the 14.8v you are seeing is the charger saying "hey, that's a 4s battery" (4 lipo cells). And since 3.7v is the accepted listed nominal voltage used by the industry, your charge is saying you have a 4s battery, and 4 x 3.7v = 14.8v. Bas8cally it is your charger recognizing a 4s battery is plugged in.