To Charge, or not to Charge?

Fully-Charged!

I can’t really say for others, but for me personally, one thing that always bothers me whenever I am purchasing a new device is how to handle the battery for first-use. This is especially important to me when getting a new mobile phone; I always make it a point to check first if it’s a Lithium-Ion or a Lithium-Polymer battery. I never really knew the difference except that I was told by an Airsoft Gunsmith that one must never, ever fully drain a Lithium-Polymer battery.

This has always confused me because I remember when I bought a mobile phone a couple of years ago, the salesperson told me to fully drain the battery first, then fully charge it at least three times before doing the random charging that everyone likes to do. It was a Lithium-Ion powered device–actually it’s always a Lithium-Ion powered device now-a-days. So I’ve been wondering, is there really that big of a difference between a Lithium-Ion and a Lithium-Polymer battery?

I hate it so much whenever my mobile phone battery degrades so bad to the point where it needs to be charged within the day just to last, so I did some research and I’ll be sharing what I’ve discovered so far. But first, let’s brush up a bit on jargon and what exactly are these Lithium-thingy batteries.

Lithium-Ion Battery

I’m sure that everyone has seen, if not owned, one of these.

Batteries are made up of chemicals that react together to produce electrical voltage in order to provide power to mobile devices such as phones, players, toys, and so on so forth. There’s actually a sort of mixture of chemicals involved, but let’s not go there since batteries are designed around a specific chemical which serves as the base ingredient, you could say.

The most common batteries are the ones that you use up, then throw away; and the base chemical ingredient in these is Alkaline. These are single-use batteries, since once drained it would be meaningless–in fact, extremely dangerous–to attempt to recharge them.

Rechargeable batteries were commonly made with Nickel as it’s base, plus another chemical. There were the Nickel-Cadmium, and then the Nickel-Metal Hydride. But like most everything else, these soon became obsolete and the world of consumer electronics has moved on to rely on a new chemical for rechargeable batteries: Lithium.

A Lithium-Ion, or Li-Ion battery for short, is the typical battery you see when you open up the back cover of your mobile phone. It is the standard battery of choice for re-chargeable devices simply because it is cheap to produce, efficient, and has a long-life.

A Lithium-Polymer, Li-Poly for short, on the other hand, is supposedly a more advanced version of the first. So what’s the difference? Actually, based on my research: Nothing really. Both are actually Lithium-Ion batteries but the latter is just made differently, and the Polymer was added to the name just to indicate the difference, but they essentially perform and are to be used the same way. You really won’t notice any difference except the name on the battery, apparently.

Okay, so now that we got that out of the way, let’s look at some facts regarding batteries. Here’s a nifty table I found:

Table 1: Dos and don’ts summary how to use, maintain and dispose of batteries.

Battery care

Lead acid: Flooded, sealed, AGM Nickel-based:
NiCd, NiMH
Lithium-ion: Cobalt, manganese, phosphate
Best way
to charge
Apply a saturated charge to prevent sulfation; can stay on charge with correct float charge. Avoid getting battery too hot on charge. Do not leave battery in charger for more than a few days (memory!). Partial and random charge is fine; does not need full charge; lower voltage limit preferred; keep battery cool.
Charge methods Constant voltage to 2.40–2.45/cell, float
at 2.25–2.30V/cell; battery stays cool; no fast charge possible.
Charge  = 14h
Constant current, trickle charge at 0.05C, fast charge preferred.
Slow charge  = 14h
Rapid charge = 3h
Fast charge   = 1h
Constant voltage to 4.20V/cell; no trickle charge; battery can
stay in charger
Rapid charge = 3h
Fast charge = 1h
Discharge

Do not cycle starter batteries; avoid full discharges; always charge after use.

Do not over-discharge under heavy load; cell reversal causes short. Avoid full discharges.

Prevent full cycles, apply some charge after a full discharge to keep the protection circuit alive.

How to prolong battery Limit deep cycling, apply topping charge every 6 months while in storage to prevent sulfation, keep cells at or above 2.10V Do not keep battery in charger for more than a few days, discharge to 1V/cell every 1–3 months to prevent memory (NiCd) Keep cool, battery lasts longest when operating in mid state-of-charge of 20–80%. Prevent ultra-fast charging and high loads.
Storage Do not store below 2.10V/cell; keep fully charged if possible Store in cool place; NiCd stores for 5 years; prime before use Store at 40% charge in cool place (40% SoC reads 3.75–3.80V/cell)
Disposal Do not dispose. Lead is a toxic metal NiCd: Do not dispose.
NiMH: Can be disposed in low volume
Can be disposed of in low volume

Alright, so you’re probably thinking, “What’s this mean to me?” Well, breaking down my research, here’s a few facts that we should keep in mind:

  • More important than how long to charge, is the environment: When charging, the battery (or device since it’s probably still attached when charging) should be in moderate temperature. Stop charging immediately and unplug if it starts getting warm.
  • Although its not a big deal to fully drain and fully charge randomly, it is recommended to not do so. It is best to keep the battery between 20% to 80%.
  • Short “burst” charging is better than leaving it to charge extended hours; for example, 1 hour at a time is better than leaving it on for 3+ hours.
  • It is recommended to turn device off when charging, this way the battery focuses on a single job whether charging or discharging and not both at the same time.
  • It’s better to remove a laptop battery if you’re going to be plugged in for long hours, not because you might over-charge (laptops typically have safeties to prevent that) but rather to avoid potentially overheating, which is much more damaging to a battery than “over-charging”.
  • And finally, when you purchase a device or battery for the first time, you neither need to fully drain nor fully charge it. The factory charge, as it is referred to, is already set at the battery’s optimum operating threshold; in other words: Just use it.
And there we are! I do hope that this was of help to you 🙂
God bless!