Is it safe to use a Lipo to replace a Li-Ion …. this is actually for a small cordless screwdriver where the battery’s gone and can easily replace with a LiPo I have to hand as always have some new spares around for my torches.
My main concern would be charging it and if there’s any risk as they’re fairly basic chargers that come with these sort of things.
LiPO are 3.2 volts (avg) vs LiIon are 3.7 volts.
Not same charger at all.
In short - NO
Just change to original battery designation / format. Solder the leads if so required.
A LiPo battery / cell is also 3.7 v nominal. Not 3.2 v, what you are thinking of is probably a LIFEPO4 cell. Those are 3.2 / 3.3 v.
So Yes it’s possible to change a Li-Ion cell with a LiPo cell.
As for the charger, I dont know of the original charger is suited to charge the LiPo.
Well, I learnt something new.
Always thought LiPo was non cylindrical batteries (typically). So I assumed the OP was talking about cylindrical LiFePo4 (Lithiun FerroPhosphate).
A ”lipo” is a li ion cell in pouch packaging. Originaly it meant lithium polymer which is a type of solid state cell that never got out of the lab, somehow it got used to describe pouch cells (flat cell with plastic film packaging). Pouch cells can be any chemistries lwith different nominal voltage, e.g LTO 2.3V, lifepo4 3.2V, NMC/NCA/LMO etc… 3.6-3.7V, 3.8V (lihv) and in high energy or high power variants, just like with other packaging, e.g. cylindrical steel can, prismatic (pouch in hard case).
Anyway, you just need to check that the nominal voltage is the same, and the the max continuous discharge rating is suitable for the application.
I use various LiPo batteries for low-drain applications. LED light strips, low output LEDs, Raspberry Pi UPS and I run a Pi outdoor camera as well on Lipo
The OP was asking if he could replace the LiIon cell from his cordless screwdriver with what I assume to be LiFePO4 (as he states he has some laying about for his flashlights). So a cylindrical, say 18650 format cell of this chemistry just doesn’t have the voltage to properly drive the device. Actually, if it has a LVP (Low Voltage Protection) circuit built-in as mine, this trips as soon as you require some torque.
And then the cradle charger (as with Skill) hasn’t the capability to charge 3.2 V. cells. If I recall, they use the led as a current limiter. Basically a trickle charger.*
I would propose using re-cycled cells from a laptop that is found anywhere on eBay. Better is use some Sanyos that have tabs pre-soldered.
Edit; *The charger would overcharge most probably.
LiFePo4 Are not regularly used in flashlights, I can’t name a flashlight that does use such type of cell. So I assumed he meant those LiPo pouch type battery’s.
So to the OP, what cell or battery do you have that you want to replace the original battery with?
How many volts is the screwdriver?
I have a drill-driver that was powered by NiCad that died. The battery pod was too small to take 3S x 18650 cells, so I put a small 3S Lipo in there. The Lipo is from radio controlled flying. They are VERY common in RC. The vast majority come with a balance tap (not a BMS), and should be charged with a suitable charger that has balancing capability. I cut a slot in the battery pod so the balance tap could stick out for charging, and individual cell checking.
Works fine.
If it’s a single cell Lion, than a single cell lipo should be fine as they use the same voltage. I +assume +the charging control is in the charger, not the screwdriver or the old battery.
if the voltage profile and drain capability of the lipo is the same of capable of higher drain its fine.
just have to be careful of internal features of the case to be sure you dont damage the cell.
this could cause anything from failure from leakage/dryout to energetic failure(flamethrower)
I do apologise to everyone …. this is me having a complete brainfart!!!
For some bizarre reason (especially as I wasn’t even on the booze the time of posting) I was thinking 18650’s were Lipo as opposed to Li-Ion so in essence I have replaced like for like apart from the capacity of the new one which is aprox 3x’s what was in there.
Just as a secondary question, does anyone know if those types of screwdriver may have some sort of protector in front of them, I’ve tried cutting the charge lead and soldering on some bullet plugs so I can charge it with a much higher quality RC charger but non of them can see the battery or say low voltage.
I’ve tried plugging the lead into the screwdriver and sticking a voltmeter on the other end and it shows nothing so I’m guessing the charger isn’t able to see there’s battery on the other end of the lead and take it’s voltage / charge status.
I would recommend investing in a digital multimeter to test the voltage of the cell and get a better idea of what’s going on.
It seems what you’re describing is the cell is so low voltage it can’t be recognized by the charger nor the screwdriver. It’s not really advisable, but there is a way to “jump start” the cell to get just enough voltage for a charger to recognize it. However if a cell is so drained and requires a jump start, the cell usually is so worn or damaged it won’t hold that charge for long anyway. I would just replace the cell if possible.
To check the polarity etc. I did take it apart and took a voltage check and the batttery’s just a bit over 4.0v’s so I’m sure there’s something in it that stops the current going back to the pins that the charger plug attaches to.
Perhaps there is a diode in there someplace to prevent voltage from passing from the battery back to the charger.
Also, often there are thermal sensors built onto the battery pack to shut things off if the battery overheats.
One of these leads might be missing or broken or needed to allow the charger to think the battery is happy - temp wise.
All the Best,
Jeff
I have a 4 pack of LiPO4 AAA cells.
Which I use in several Small torches that ARE proven safe with them.
Also bought a LiitoKala Lii202 charger which charges them ,
along with the Li Ion and others.
With suitable torches. (Check on here and elsewhere forums).
They give pretty much twice the safe output
compared to the std AAA cells.