M18 power source

[Uncle Al]

I bought a Milwaukee M18 power source to use on the ice, but I haven't gotten there yet. First power source I bought, the 12v port didn't work, so with the item having a 1yr warranty I sent it back. No questions asked I got a new one in the mail yesterday, and guess what, this new one, out of the box, doesn't work from the 12v port either. Now I'm pissed. I called Milwaukee and talked to a rep that said the power source was intended to be use on "Heated Jackets" only. I've read here on the forum of guys using their M18 power source to run vexilars, HB fish finders, lights, camera's anything that requires 12v dc, and having luck with them.  I am not having any luck with these power source's. 

[Kevin23]

We have used them, but yea they do suck. They do not last very long at all and only have something like 800mah output. Just use an adapter and dc to dc voltage converter, shouldnt cost more than $10.

[MT204]

Yaa.
I have posted numerous times over the last few years on the Milwaukee (and other) "power sources".
They were designed to run a resistance load such as a jacket.
They were never designed to run an expensive piece of electronics!!
Always question what you read on a forum?

[RStock521]

Alternative would be to get one of those 3D printed adapters and a drok stepdown voltage regulator.

[ran7ger]

 I think that's milwaukees response after having to warranty too many.  Personally I've used the m18 power source for 2 seasons on my ice55.  Just ran it for 42 hrs straight with an 8ah battery, works great for me.  Also used it to run fans, lights..

[RStock521]

I think that's milwaukees response after having to warranty too many.  Personally I've used the m18 power source for 2 seasons on my ice55.  Just ran it for 42 hrs straight with an 8ah battery, works great for me.  Also used it to run fans, lights..

Yeah, that could be true. I've also used mine to power lights/fans and occasionally my Garmin 73SV without issue for years.

[Fishrmn]

I bought one a few weeks ago.  My SLA battery gave up the ghost.  I looked at Dakota Lithium batteries, but couldn't go for the idea of putting that much money into a battery that would need a charger to go with it, when I have 3, 9 amp hour Milwaukee batteries that don't get much use in the winter.  I've only used it twice, but couldn't be happier.  I can always just grab a battery off of the charger and go.


Fishrmn


⫸<{{{{⦇°>

[Uncle Al]

sent an email to Milwaukee Tools about this being the second power source that was bad, and they wanted to know what I was trying to power with it. Told them I had checked it with a VOM to see if it put out 12v before I hooked my Helix 7 to it, and there was no voltage except on the USB port.

[kpd145]

Alternative would be to get one of those 3D printed adapters and a drok stepdown voltage regulator.

This is what I did so my 40V strike master batteries would get used. Its about 16ah at 12v, it gives me 2 trips before I need to charge running a Garmin 93sv

Its worked now for about a year with no issues, both for ice and salt.

[Kevin23]

This is what I did so my 40V strike master batteries would get used. Its about 16ah at 12v, it gives me 2 trips before I need to charge running a Garmin 93sv

Its worked now for about a year with no issues, both for ice and salt.

To elaborate on this a bit for people reading, look at your batteries at Wah not AH. Most tool batteries list the Wah on the bottom, if they dont then it nominal voltage times amp hour. 40V 5ah battery is a 200Wah battery, so it can deliver 200Watts for 1 hour, or 20 watts for 10 hours, or 10 watts for 20 hours etc. To figure out how many watts your unit draws you need to know its true amp draw, you do this with a multimeter. Divide the watt hours of your battery by the watts your unit draws and that is how long it will run. The whole "my unit can run 4 days, or my unit can run a full day" is subjective unless you really do mean 24 hours per day. Some people fish for 2 hours, some 12 hours.


For instance my garmin 73SV UHD draws 0.55A at 13V on max brightness so that is 7.15W it is drawing. That 200WAH battery rigged to a step down to 13V would last me right at 28 hours. If I use a 7ah 13V lithium then that is 91Wah, so my unit will run for 12.75 hours. If I was to use a 5AH milwaukee m18 battery that is 90Wah, so it will run 12.5 hours which is almost identical to the 7ah 13V lithium.

Its pretty easy math to do, but only works with lithium batteries because of their near perfect efficiency (about 95-97%), figure youll get about 80% available Wah with a lead acid SLA. Using a 9ah SLA I would get about 12 hours. That is the benefit of running lithium, along with weight savings.

[MT204]

Its pretty easy math to do, but only works with lithium batteries because of their near perfect efficiency (about 95-97%), figure youll get about 80% available Wah with a lead acid SLA. Using a 9ah SLA I would get about 12 hours. That is the benefit of running lithium, along with weight savings.

Ohms law.
A battery is rated at what it is tested at.
It doesn't matter what type of battery they all calculate the same, efficiency is part of the battery rating.
Lead acid, Nimh doesn't matter.
A watt is a watt, an amp is an amp and an hour is well an hour.
A 9ah SLA @12 volt is 108 Wah. 108Wah divided by 7.15 watt draw is 15.1 hours not 12.5.
But your mileage may vary.

[Kevin23]

Ohms law.
A battery is rated at what it is tested at.
It doesn't matter what type of battery they all calculate the same, efficiency is part of the battery rating.
Lead acid, Nimh doesn't matter.
A watt is a watt, an amp is an amp and an hour is well an hour.
A 9ah SLA @12 volt is 108 Wah. 108Wah divided by 7.15 watt draw is 15.1 hours not 12.5.
But your mileage may vary.

No that is not correct, SLA batteries are rated on their whole capacity when charged from 0V to 13V. The available range of use is called the "efficiency" and it is rated at about 80% for SLA on AH and actually less on Wah (I did not remember this part). You get about 80% usable AH energy from the batteries full rated capacity depending on how fast you discharge it (faster = less usable capacity). You will get 80% of 9AH when using a SLA battery, maybe as low as 70% if you use a high current draw like a lton of lights. If you discharge it at about 10ma you'll probably be able to get the full 9AH but that is not practical. That's just how lead acid batteries work, and why everything is going to lithium now.

[MT204]

No that is not correct, SLA batteries are rated on their whole capacity when charged from 0V to 13V. The available range of use is called the "efficiency" and it is rated at about 80% for SLA on AH and actually less on Wah (I did not remember this part). You get about 80% usable AH energy from the batteries full rated capacity depending on how fast you discharge it (faster = less usable capacity). You will get 80% of 9AH when using a SLA battery, maybe as low as 70% if you use a high current draw like a lton of lights. If you discharge it at about 10ma you'll probably be able to get the full 9AH but that is not practical. That's just how lead acid batteries work, and why everything is going to lithium now.

If that were true it would not be a 9ah battery!
I've test hundreds if not thousands of batteries.
A 9ah battery will run a 9 amp load for an hour, that's why it's called a 9amp hour battery.
Now that number can be tweaked a bit depending at what the shut off voltage of the test is.
Ohms laws is ohms law!

[Kevin23]

That is contrary to what most literature on the subject states. I am not going to sit and explain it, but anyone who wants to learn about it can google "sla battery efficiency" and read why they do not give a true amp rating in real world tests.

Since you keep repeating "Ohms law". Ohm's law is amps = voltage divided by resistance. Let me know how this has anything to do with SLA battery chemistry not giving the rated capacity. 

[MT204]

That is contrary to what most literature on the subject states. I am not going to sit and explain it, but anyone who wants to learn about it can google "sla battery efficiency" and read why they do not give a true amp rating in real world tests.

Since you keep repeating "Ohms law". Ohm's law is amps = voltage divided by resistance. Let me know how this has anything to do with SLA battery chemistry not giving the rated capacity. 

So what your saying is a 9 amp SLA really isn't 9 it's something else?
I will say that sla batteries are less efficient than some of the newer chemistry batteries,  they may well be 80% less than a Lithium but they are still a 9Amh battery.
Are you saying that for example a 9AH Lipo battery really isn't 9 it's more than 9 because it's more efficient? If so that's incorrect it's still a 9Amh battery!
As far as ohms law?
It has to do with anything electrical battery or other wise!
First you test the voltage of the battery.
Then you apply a load to the battery in the case of a 9 Ah SLA, 9 amps.
Run the test (one of these works nicely http://www.westmountainradio.com/product_info.php?products_id=sys500_watt).
Then take the volts, amps and time and calculate the rating of the battery!
Sad but true I don't have a SLA battery handy or I'd run a test for you.