I’ve been testing used batteries. This first graph shows four different 4ah m18, each around 5 years old. The upper blue line is voltage and lower red current w/ axis values to the right. The power is the central plot. These are spec’d at 72wh, so each is well within 10% of that at 5 years old.
If you use this sort of cell, at 16 volts, you’ve used 90% of the available energy. Below 15, they crash pretty quick.
M18_power_tests_4ah.png
Here’s a single 3yo Dakota. This is spec’d at 120wh, so almost spot on.
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Here’s a 3 yo power tech. To not upset the universe, they underrated it @ 8ah. Using the Dakota method, this should be 96wh. I was able to measure 104wh.
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Here’s a currently known as Amped outdoors LiFePO4. This is a one year old 10ah flavor and uses a 12.8 factor to get 128wh on the label. It tested off by a significant margin @ only 77% of listed capacity.
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You’re pretty smart about these things I’ve learned from your previous battery posts.
From what you can tell, are the Dakota and Amped using the same cells/build structure? I’m kind of shocked to see the Amped diminishing so quickly. I have 2yr old Dakota that seems to still be running strong but I have no way to quantify that.
From what you can tell, are the Dakota and Amped using the same cells/build structure? I’m kind of shocked to see the Amped diminishing so quickly. I have 2yr old Dakota that seems to still be running strong but I have no way to quantify that.
Ive never pulled apart an Amped or Dakota, only a failed bamboo lithium, the predecessor of the Dakota. I’m guessing they are pretty much the same design, but maybe differently sourced cells.
A single battery test really means very little, only that specific battery is less than rated. The battery I tested was a friends, I will test my 1yo energized 10ah and three 10ah bamboo batteries to see how they perform in comparison at 7 years old. I ran the same test the day I got the energized 10ah last year and it was spot on.
50WoutputPowercurve_EO10ah.png
It would be interesting to take one of these LiFePO4 batteries to see what using a “standard” SLA type charger does to them. Basically see if using a standard charger actually lessens the life of the battery at all due to the regular lower amperage charging.
I know some sellers say you can use a standard charger but I wonder what detrimental effects it has over the long run.
Maybe nothing, but my mind wonders.
fishwater – Weren’t the old Bamboo’s made up of faulty cells? Or is that not true?
My understanding is Dakota now makes a fantastic product
Fundamentals apply here: quality cells are key to a major longevity difference in lifepo4, voltage/current dropoff is higher, but also occurs due to a differing amp hour rating, and even mediocre ones still outperform lithium ion. This doesn’t even factor in parasitic draw using a voltage converter on 20v. My conclusion: it’s a waste of money converting drill batteries for flashers.
fishwater – Weren’t the old Bamboo’s made up of faulty cells? Or is that not true?
My understanding is Dakota now makes a fantastic product
I never heard that about the bamboo. I had six for a long time, 5 still run strong. Four for sure, I gave two away, lost track of the one.
The rapala battery had issues with cells, maybe you’re thinking of that deal? Maybe related to a lack of proper BMS? I tried to get ahold of some of the “bad” batteries to canabalize cells from, but it never happened and I moved to m18.
I tested my personal 10ah EO again today, it gave out a solid 116wh, only a few less than the initial test Nov 2018. Maybe 50 charge cycles?
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: it’s a waste of money converting drill batteries for flashers.
Why? Seems like a waste to buy a different battery when you already have them? On a watt-hour basis, I’ve been told they are lighter also. They work great. And, having a single battery and charger type on road trips has value. Way easier to carry spares anyhow.
No kidding especially in a suit pocket
<div class=”d4p-bbt-quote-title”>iTinker wrote:</div>
: it’s a waste of money converting drill batteries for flashers.Why? Seems like a waste to buy a different battery when you already have them? On a watt-hour basis, I’ve been told they are lighter also. They work great. And, having a single battery and charger type on road trips has value. Way easier to carry spares anyhow.
Replacement cost is high, they’re higher drain, lower life, and you only have 1 charger. I’d rather have a few lithium chargers going at once than wait for 1 drill battery charger for my family’s gear. To each their own, but if I were looking for a cost effective power solution, this wouldn’t be it.
Replacement cost is high, they’re higher drain, lower life, and you only have 1 charger. I’d rather have a few lithium chargers going at once than wait for 1 drill battery charger for my family’s gear. To each their own, but if I were looking for a cost effective power solution, this wouldn’t be it.
Who says you can’t buy more than one charger? Or why not just get something like the Milwaukee 6 pack charger if you’re so worried. One charger 6 batteries.
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At what cost, and to what end? Your original premise was to use batteries you had, but now you’re buying extra chargers, and they still don’t last as long. I could buy an extra lifepo4 and 6 chargers for the price of that thing. I get there’s confirmation bias, but it clearly is not cost effective unless you’re a contractor. I honestly don’t care how you blow your money.
<div class=”d4p-bbt-quote-title”>iTinker wrote:</div>
Replacement cost is high, they’re higher drain, lower life, and you only have 1 charger. I’d rather have a few lithium chargers going at once than wait for 1 drill battery charger for my family’s gear. To each their own, but if I were looking for a cost effective power solution, this wouldn’t be it.
Who says you can’t buy more than one charger? Or why not just get something like the Milwaukee 6 pack charger if you’re so worried. One charger 6 batteries.
and they still don’t last as long. I could buy an extra lifepo4 and 6 chargers for the price of that thing.
Replacement cost is high, they’re higher drain, lower life, and you only have 1 charger.
Why don’t they last long, have lower life? Sounds like a great reason to avoid m18, but is it really true?
And, if you are able to shop around, you can find amazing deals on M18 batteries. I got my two 12ah (18ah equivalent) for $399 with a free chainsaw, or at today’s saw price, two 12ah m18 for a few bucks each. The last drill kit i purchased was on sale and came with a “free” third battery. Also, I’d contend it’s far easier and safer to carry considering they are designed with workplace safety foremost. I’ve seen sla replacement lithiums start a few fires by simple mechanical shorting.
“Why don’t they last long, have lower life? Sounds like a great reason to avoid m18, but is it really true?”
Yes, running a voltage converter causes parasitic draw. It’s true that higher voltage+amperage will constitute more over all power, but when voltage drops off combined with parasitic draw you lose its potential energy. It also fails to address the repeated charge capacity rating when comparing lifepo4 cells with minimal dendrite issues and lithium ion cells which have known dendrite issues.
“And, if you are able to shop around, you can find amazing deals on M18 batteries. I got my two 12ah (18ah equivalent) for $399 with a free chainsaw, or at today’s saw price, two 12ah m18 for a few bucks each.”
The average ice fisherman isn’t spending $400 on a battery powered chainsaw.
“The last drill kit i purchased was on sale and came with a “free” third battery.”
Happy for you.
“Also, I’d contend it’s far easier and safer to carry considering they are designed with workplace safety foremost. I’ve seen sla replacement lithiums start a few fires by simple mechanical shorting.”
If this were your original point to begin with, i’d agree that contractor cells are safer than sla designed ones. Lifepo4 cells aren’t sla, and cheap protection circuits are in cheap batteries, not well made ones. That being said, dendritic lithium ion cells catch fire very easily, and li-ion cells are highly susceptible to fire from mechanical damage.
Here’s a test of three bamboo batteries that are 7 years old. They’ve each held up extremely well, still near 10% of specification. I used these year round for the first 5 years, but they’ve had limited use the past couple years.
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