Lithium battery charging regimes and out of use storage

[davidmh]

A lot of boaty things now have lithium batteries which require charging, I have had lots of conflicting advice on the best way to charge and get a good life out of the batteries. the comments I have had are
Dont let the batterry run out completely, you may find it difficult to recharge.
Dont leave it for long periods with 100% charge, best level is around 60%
Dont just use a liitle bit of battery and then recharge to 100%, or worse still just charge it up a liitle bit.
Batteries like to be used ideal is to use it until it is down in the 10% range then charge it back up to 100% or 90+%.
Dont leave your battery on charge for long periods when it is at 100%
I thought lithium had done away with all the charging problems with Ni-Cad and Ni-MH batteries !!
What is forum views.
uses of battery such as, drills, tablets, dinghy air pimps, elecric outboards, torches, hand held VHF etc

 

[Shaz77]

I am probably wrong but I usually charge my tools etc batteries if they run down and the tool stops working or other than that, when I think about it. I may look at a torch or kindle and think I haven't charged that lately. Some of my blue tooth items tell me of the charge on the item they are connecting to. I have no organised routine.

 

[Clash]

A lot of boaty things now have lithium batteries which require charging, I have had lots of conflicting advice on the best way to charge and get a good life out of the batteries. the comments I have had are
Dont let the batterry run out completely, you may find it difficult to recharge.
Dont leave it for long periods with 100% charge, best level is around 60%
Dont just use a liitle bit of battery and then recharge to 100%, or worse still just charge it up a liitle bit.
Batteries like to be used ideal is to use it until it is down in the 10% range then charge it back up to 100% or 90+%.
Dont leave your battery on charge for long periods when it is at 100%
I thought lithium had done away with all the charging problems with Ni-Cad and Ni-MH batteries !!
What is forum views.
uses of battery such as, drills, tablets, dinghy air pimps, elecric outboards, torches, hand held VHF etc

All of the above are correct. But I wouldn't be bothered trying to manage tool batteries under that regime.

Most of those batteries aren't capable of having their SoC measured in percentage terms. They're either fully charged or not.

 

[Neeves]

Your small batteries for tools are a different chemistry to your house bank. Don't mix them 2 up. But don't leave them, tools, on charge once the battery indicates its full - small battery charges are not very sophisticated and the combination of economy, different chemistry, over charging is the cause of fires and the bad name, incorrectly, to any battery with lithium.

Your house bank requires more care - it cost s a lot more than a drill battery.

I think when you get replies it will be useful if you list what house battery you have, what it is charged from etc. what you will leave active when you leave the yacht for a long period, bilge pumps and whether they come on frequently etc.

Jonathan

 

[William_H]

It is essential to charge any lithium cell or battery with a charge controller. This must sense cell voltage and stop charging when fully charged. It also will check for balance of cells in a battery. Now all phones, lap top computers and specialised tool battery chargers (or battery itself) will have the charge management circuit and also discharge disconnect on low voltage. Most lithium iron 12v batteries will also have a built in charge controller.
It can all get a bit confusing with detailed posts here from people who have bought individual cells and added there own charge controller. Not the most common way to go. Respect to those who do that.
So the rules of no trickle charge after full charge and charge cut off should be handled by charge controller'
Yes lithium batteries and cells are always supplied new with 50% charge. However I doubt many users will try to store there batteries at half charge. Simply because we want full charge when we use them. Based on the number of lithium cells and batteries in use world wide this does not seem to be a great concern.
When i look around my fairly ordinary household I am shocked at the number of lithium cells and batteries. Shocked because the local fire brigade seem to constantly on the news reporting house fires from lithium batteries. It does seem however that the culprits more often are E scooters. Although one recently seems to be from drill type battery.
Mean while I have recently bought 4 Life 12v batteries for mobility scooters. They have charge controllers built in. I charge them from 2x 10w solar panels in series. So about .5 amp charge shared between 2 scooters at 24v. I did fit a voltage limiting device to the panel output to limit voltage from 40v down to 30v when there is no charge load. ie 15v max per battery. No other solar controller. Slow charge but OK.
I have set up a steel box to store drill batteries etc in. Hopefully being outside shed might protect us from house fire. Although I must remove from the box for charging.
The adventures of lithium batteries . ol'will

 

[Sea Change]

Sometimes ease of use outweighs maximum cell life. I like to have my tools and torches fully charged, so that when I need to grab something I know it will work.

It's not a crime to fully charge a lithium battery and then put it in storage. What's much worse is leaving it plugged in to the charger all the time. That's bad for cell life and can also be a fire risk, in the case of cheaper badly designed stuff.

It's also not good to run them right down, that's when dendrites start to form and you get permanent cell damage which manifests as bulging and loss of capacity.

But they don't have memory effect and they aren't adversely affected by not getting to full charge regularly.

So in a nutshell: don't completely discharge whilst using. Charge it when you're done. Take it off charge when it's full.

(If you really, really want to get maximum lifespan from your battery, aim to have it around 50-70% full most of the time. But that's quite hard to do in practice because you're unlikely, with normal electronics, to know when it's at that level. And with 1-3% self discharge per month, you'd need to go and top it back up every so often. IMHO it's not worth worrying about).