Question about battery capacity

[Lei]

Can we replace a device batt with something of a higher amperage? Say 3x more

Does the battery tell how much it's full, or device checks the amount?
I doubt device checks, because what happens if you not use a battery for long enough and lose some charge.
I'm worried if I replace a 1000mAh with 3000mAh, it would get charged upto a limit that device is designed for.

Or is it that battery knows its current % and can tell the device to keep charging until I'm full?

 

[kyletreg]

Its ok, what might happen is the % will act weird for a bit while the device adapt to the new battery.

 

[Solaris17]

Its ok, what might happen is the % will act weird for a bit while the device adapt to the new battery.

yup this.

 

[1freedude]

Also, the charge time will be as many times increased as the capacity increase.

 

[Count von Schwalbe]

Lithium batteries are charged to a specific voltage, which is closely related to their charge in amp/hours. As long as the voltage is identical (it should be, but it depends on the number of cells) you will be fine. As noted above, the voltage/charge curve may be slightly different, so the percentage may be slightly inaccurate.

 

[dragontamer5788]

Depends on the chemistry, depends on a lot of things, depends on the charge circuitry.

Having 3x C (C == capacity) means that your battery will sink 3x more current during charge. Is your charge circuitry constant-voltage? Well, bam, you just ran 3x more amps than the CV circuit expected. Maybe that makes the CV circuit overheat, I dunno.

Or is the charge circuitry constant-current? Then it'd be fine (CC == op-amps and other crap that measures the current to ensure that nothing bad happens).

Does the battery tell how much it's full, or device checks the amount?

Its impossible to know the state of charge of most battery chemistries today. The way "fuel gauges" work is by measuring / counting / coulomb counting in practice, but that requires a timer + model to figure out the internal leakage of cells. So... yeah... depends on chemistry.

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I'd say... Lead Acid is probably fine (most Lead Acid batteries are CV-CC). Lithium-ion is lol complex (the charge controller might be part of the cell, it might not be, who knows where it is? There's also LFP vs LiPo vs Li-ion and all sorts of minute chemical differences).

I'm about 50/50 on NiMH. A trickle-charge NiMH probably relies upon the C-capacity being in a certain range, but a CV-CC fast charger NiMH with temperature control probably could figure things out??

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Can you give more details: What chemistry are your cells? What device are you putting them into? Etc. etc. What's your charger?

Its ok, what might happen is the % will act weird for a bit while the device adapt to the new battery.

This is only true if the charge controller is built into the battery, such as laptops. This is absolutely not true for NiMH cells or SLA cells, or unprotected 18650 Li-ion cells. There's a lot of different batteries in the wild, and the topic poster hasn't given enough details for anybody in this topic to make any kind of recommendation.

I'm hoping you're not dealing with unprotected 18650s, which are prone to explode when you perform these kinds of experiments on them.

Vape batteries can cause deadly explosions, consumer safety agency warns

Individual 18650 lithium-ion cells can cause a serious risk.

www.theverge.com

Agency Warns Against Buying Repackaged '18650' Batteries That Present Fire and Explosion Risks

The U.S. Consumer Product Safety Commission warned consumers against purchasing 18650 batteries — which are often used to power vapes and other small devices — due to the risks associated

people.com

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So please, be more specific. What cells, what chemistry, what batteries are you talking about exactly.

 

[thesmokingman]

It really depends on the chemistry. This is an ex. of a bad idea switching from a lead acid setup whose charge is intended to only charge lead acid, and ppl convert to lithium. Eventually the lithium will die due to the wrong type of charger/lack of charge. And then if its lithium, you better have a BMS for it too.

 

[electrowind]

Can we replace a device batt with something of a higher amperage? Say 3x more

Does the battery tell how much it's full, or device checks the amount?
I doubt device checks, because what happens if you not use a battery for long enough and lose some charge.
I'm worried if I replace a 1000mAh with 3000mAh, it would get charged upto a limit that device is designed for.

Or is it that battery knows its current % and can tell the device to keep charging until I'm full?

It's generally not recommended to replace a device battery with one that has a much higher amperage than the original battery. This is because the device is designed to operate with a specific type of battery, and using a battery with a significantly different amperage could potentially cause damage to the device, including overheating, short-circuiting, or even battery explosion.

Regarding your question about whether the battery or device determines the battery's charge level, it's actually a combination of both. The battery contains a small microchip called a "fuel gauge" that keeps track of the battery's charge level and communicates that information to the device. The device also has its own software that monitors the battery's charge level and may adjust its charging behavior based on the information provided by the fuel gauge.

If you replace a 1000mAh battery with a 3000mAh battery, the device will still use the fuel gauge in the new battery to determine its charge level. However, the device may not be designed to handle the larger battery capacity and may not charge the battery to its full capacity, or may charge it too slowly. Additionally, the larger battery may not fit properly in the device's battery compartment, which could cause other issues.

It's generally recommended to use a battery that is compatible with your device's specifications to avoid any potential damage or performance issues. If you need a higher capacity battery, it's best to look for one that is specifically designed for your device and is compatible with its charging and power management systems.

 

[ArdWar]

Exchanging capacities are usually fine most of the time. Though you HAVE to make sure the battery is of the same series amount (same 1S, 2S and so on), and of the same chemistry. Lithium batteries come in several flavor. Li-Ion have 4.1v full charge per cell, LiPo have 4.2v, LiFePo have 3.3v. Exchanging Li-Ion to LiPo is fine, exchanging LiPo to Li-Ion is usually fine but probably shorten its life, exchanging any other to LiFePo (or the other way around) won't work, with sparks and fires potentially involved if you insist.

 

[TumbleGeorge]

Depending of 1000 to 3000mAh this capacities range suggested something like mobile phone. Too large for smart watch and ink paper devices like ebooks, too small for tablets and laptops.

 

[Lei]

It's generally not recommended to replace a device battery with one that has a much higher amperage than the original battery. This is because the device is designed to operate with a specific type of battery, and using a battery with a significantly different amperage could potentially cause damage to the device, including overheating, short-circuiting, or even battery explosion.

It's generally recommended to use a battery that is compatible with your device's specifications to avoid any potential damage or performance issues.

Additionally, the larger battery may not fit properly in the device's battery compartment, which could cause other issues.
If you need a higher capacity battery, it's best to look for one that is specifically designed for your device and is compatible with its charging and power management systems.

Depending of 1000 to 3000mAh this capacities range suggested something like mobile phone. Too large for smart watch and ink paper devices like ebooks, too small for tablets and laptops.

good analysis, but two batteries with same dimensions being 2000mAh apart, or a phone that a battery even 2 millimeters larger can fit in it, makes the phone a wrong guess.

Or is the charge circuitry constant-current? Then it'd be fine (CC == op-amps and other crap that measures the current to ensure that nothing bad happens).

Charge via USB-C

I'd say... Lead Acid is probably fine (most Lead Acid batteries are CV-CC). Lithium-ion is lol complex (the charge controller might be part of the cell, it might not be, who knows where it is? There's also LFP vs LiPo vs Li-ion and all sorts of minute chemical differences).

LIP

Can you give more details: What chemistry are your cells? What device are you putting them into? Etc. etc. What's your charger?

Want to change this battery:

To this:

	thickness mm	width mm	height mm
Stock	8	30	40
MOD	8	40	66

both 3.7v
I know you say it doesn't fit, but it can be placed on top of the board if you turn it 90°. (not in the battery compartment)

kinda like this:

 

[Count von Schwalbe]

Should be fine, those are sufficiently "dumb" that there should be no cell management issues.

 

[R-T-B]

Should be fine, those are sufficiently "dumb" that there should be no cell management issues.

It's a lithium cell, so I'd hesitate to assume that.