Battery Terms
- Don’t leave small batteries (NiMh, NiCd, Li-Ion) on charge for long after they are fully charged, and certainly not for days on end
- A monthly or bi-monthly full discharge and charge works well for small batteries (but don’t do it every time you charge them, just occasionally) but it is bad for lead acid batteries
- Most rechargeable batteries don't reach full capacity until they have been discharged and charged a few times (a dozen or so). Prior to that, they are probably about 90% of true maximum
- Don’t leave a lead acid battery on charge for more than a day after it is fully charged unless your charger has “peak detection” or “float mode”
- There is a myth that lead acid batteries discharge if they stand on concrete. It was true a few decades ago, when batteries had cases made of wood and tar, and even when their cases were porous rubber, but a modern battery doesn't mind concrete!
- Don’t use a car battery in a boat (the plates aren't designed for marine conditions, and it won't last well - so false economy)
- Don’t use a starting (cranking) battery for an application that will run it down more than a few % before it is recharged
- Keep an eye on temperature during charging. Batteries that get noticeably hot should be allowed to cool off
- Leave the caps closed ON a lead acid battery during charging. They are vented, and don't need to be open
- If you are maintaining a battery by adding distilled water, do it after charging, not before (unless the plates are uncovered at the top, in which case JUST cover them before charging)
- Old chargers are (usually) not as good for batteries as new chargers. If you are using a device that was manufactured in the good old days, it’ll probably cost you in battery replacement or performance
- The electrolyte in a lead acid battery can settle (stratify) if the battery isn't moved (eg in a solar storage bank) which leaves the cells with concentrated acid at the bottom, and acidy water at the top - which reduces capacity. For static batteries, an occasional good charge will cause them to bubble and will mix the electrolyte. This equalising charge is worth doing about once per month - with a serious charger
- If you are charging unprotected LiPo batteries (eg for radio control applications), make sure that they are tended (not left unattended) and that they are in a suitable charging bag or similar
- If your phone is losing charge too quickly, check that Bluetooth and wireless are turned off when you aren’t using them. These two are the usual culprits
- If your laptop is usually plugged in, and it is capable of running without the battery, take the battery out until you might need to unplug it. The battery does not like being constantly charged by the laptop power supply, and will be much happier if it is fully charged, then discharged almost fully before being plugged in again
- If your car battery is registering 10 volts, it’s a good sign that 1 of the 6 2 volt cells may have failed. It almost certainly isn’t for lack of charge
- But...if someone left the lights on and your car battery is completely flat, and if it won't charge, it may be that your charger doesn't see enough volts to start charging. Get the battery checked, because a good battery specialist will have, and sometimes even sells, rescue chargers to handle this situation
- If you have a bank of batteries, maybe for solar storage, or for the house system on a boat for example, if one battery fails then get it out of the pack quickly, because it will "bring the others down" if it can. In the same way, don't buy one new battery and put it into a bank of old batteries (over 6 months old). If you do, the old batteries will "cannibalise" the new one, until it is reduced to the same condition as they are - batteries don't like tall poppies
- Battery life is, to some extent, a function of design. Some batteries are designed to “put a quart in a pint pot”. Like anything that is highly-stressed, or running as fast as it can, the pace may be unsustainable
- Car batteries are generally oblong, with a plastic case and a combination of lead and acid inside, which is where the similarity ends. They might look alike, but there is a huge difference between a quality battery and a cheap battery - and high cranking amps isn't always a sign of a good battery - in some cases it just means more acid and less (expensive) lead. Good lead acid batteries are surprisingly heavy
- In general, buy the best and most suitable battery, not the cheapest, and you won’t be disappointed.