Refueler
Well-Known Member
Seemed pretty obvious that he wasn't connecting an 18v battery to a 12v battery and getting it to charge
I agree - but he quoted my post .... which usually means what person writes is in reply to the quote.
Inverter
- Thread starter SteveIOW
- Start date
I agree - but he quoted my post .... which usually means what person writes is in reply to the quote.
Boater Sam
Well-Known Member
Certainly was, apologies for addressing to you.
Trident
Well-Known Member
I can't argue with you - but as I said my Makita tools specifically warn against non genuine chargers so I'll stick with their advice for the layman.
Trident
Well-Known Member
Yes I should have made that clear - thanks for doing so.
Kelpie
Well-Known Member
Re: charging efficiency.
This only really matters if power is in short supply. It's obviously best to get dedicated 12v chargers for power tools, laptop, etc, but it can be a bit of an extravagance if you're not using them often.
An inverter capable of powering the biggest load is going to be cheaper and far more flexible.
On hoovers, you can't really beat a 240v one. I've had a 12v one, it was slightly less useful than a dustpan and brush. I've had a Dyson handheld rechargeable which was ok but very expensive and the battery died after a few years. And now I use a £30 wet and dry vac, 1000w, and it's amazing. But that needs a big inverter and the power generation to go with it.
This only really matters if power is in short supply. It's obviously best to get dedicated 12v chargers for power tools, laptop, etc, but it can be a bit of an extravagance if you're not using them often.
An inverter capable of powering the biggest load is going to be cheaper and far more flexible.
On hoovers, you can't really beat a 240v one. I've had a 12v one, it was slightly less useful than a dustpan and brush. I've had a Dyson handheld rechargeable which was ok but very expensive and the battery died after a few years. And now I use a £30 wet and dry vac, 1000w, and it's amazing. But that needs a big inverter and the power generation to go with it.
bill bligh
Well-Known Member
ebay or Gumtree used suitcase generator
wingcommander
Well-Known Member
As confirmed above its has its own inbuilt invertor circuitry. My drill came packaged with the standard 240vollt charger. However they stocked a 12 volt ciggie lighter fed charger also which is great for mobile charging in-between jobs and bonus for boat work. It did pop the inline 10 amp fuse in the van once but like I said ,it pulls circa 9 amp at 14 volts ( with alternator supply) so I guess its a tad more when engine is off . Great piece of kit to have though. The Dewalt is a lithium so hence the low resistance to suck up them amps.
Refueler
Well-Known Member
Fine - no argument ....
My post was to explain the use of perfectly safe alternatives - which in fact would be cheaper than buying a decent inverter and more efficient.
I know there are others on this forum who have similar chargers and experience to me .... as they also play with Lithium powered models etc.
Just to comment : My gardener has his own Makita drill and batterys ... he brought them to me one day as the Makita charger was failing to fully charge the packs he has ..... I connected to one of my chargers ... full charge - auto shut off ...
We found the fault in the charger ... so he still uses it at home ... but if he uses the drill at my place - then my charger does the biz.
Refueler
Well-Known Member
AngusMcDoon
Well-Known Member
At the moment, or at least a few minutes ago before skiving and reading the forum, I am working on configuring the charging controller chip for a multi-cell lithium battery that powers a portable medical device. It's dull work, but it pays for boat toys. The charging controller chip has 155 settings that need to be configured to get the optimal charging for the specific battery pack it is connected to. Profiling of the battery is done by the product developer (the hardware engineers I work with), then the results of the profiling are sent to the charging controller chip manufacturer (Texas Instruments in this case) who then run the profile data through their algorithms and send the values to write to the chip's settings back to me, and I program them into the controller chip.
There are also generic charging controller chips that are much simpler. They also work and are safe, but provide less optimal charging in terms of charging speed, battery life and charging capacity. I don't know whether Makita tools use generic or profiled charging controllers, but if the latter that partly explains the additional cost.
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Refueler
Well-Known Member
I forgot to add as well ... my chargers can also discharge the Lithium batterys to the recc'd storage charge level - that most power tool chargers cannot do.... and auto shut down at that level.
Alan S
Well-Known Member
SteveIOW,
You asked
"Is it not possible to recharge the 12v rechargeable tool batteries direct from the 12v boat batteries?"
The answer is Yes. That's exactly what I do. By far the simplest and cheapest and most efficient way. I used the plug part of a dud tool battery to make a lead, but you could solder the wires straight to the tool.
KISS
Edit.. sorry didn't read your post properly. I don't charge the tool battery direct from the boats 12v battery. (don't think that would be a good idea). I run the tool direct from boat's battery.
You asked
"Is it not possible to recharge the 12v rechargeable tool batteries direct from the 12v boat batteries?"
The answer is Yes. That's exactly what I do. By far the simplest and cheapest and most efficient way. I used the plug part of a dud tool battery to make a lead, but you could solder the wires straight to the tool.
KISS
Edit.. sorry didn't read your post properly. I don't charge the tool battery direct from the boats 12v battery. (don't think that would be a good idea). I run the tool direct from boat's battery.
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Kelpie
Well-Known Member
We had an old drill like that at work. Carried it around with a 80Ah battery on it. Beat that, Milwaukee 
William_H
Well-Known Member
I think if Op is prepared to accept possible large load on boat 12v battery then yes a small inverter (pure sine wave) might be the simplest answer to charging a variety of cordless power tools.
There has been a campaign on local media here re house fires due to lithium battery charging. Like battery scooters. It seems to me that the chargers designed for fast charge are the biggest danger. I think most power tools are relatively slow charge like 3 or 4 hrs. Even at slow charge rate it is critical that at full charge voltage the whole charging is shut down. (no trickle charge) it also seems to be critical to monitor each cell for voltage balance. This is often done in the battery pack themselves.
With this concern re fire on charging I would suggest sticking to recognised common brands using their correct charger. At least you know there are thousands like it in use with no fires. Even so I would not leave a charger on over night or unattended and on the boat just do enough recharge to meet your needs. If at all possible (at home) charge in a place on a surface where battery fire might be less catastrophic.
Yes I might be OTT regarding safety here as there are just so many millions of lithium batteries being charged every day. Of course there are other more efficient options than an inverter for charging like 18v batteries from 12v but you may be going into a less popular non standard charger which may increase risk.
However if you go inverter you must always be aware of power consumption of any device you might use. Beware 240v power tools have large current draw at start up, any deice with heating in it, microwave oven and 240v vacuum cleaner. ol'will
There has been a campaign on local media here re house fires due to lithium battery charging. Like battery scooters. It seems to me that the chargers designed for fast charge are the biggest danger. I think most power tools are relatively slow charge like 3 or 4 hrs. Even at slow charge rate it is critical that at full charge voltage the whole charging is shut down. (no trickle charge) it also seems to be critical to monitor each cell for voltage balance. This is often done in the battery pack themselves.
With this concern re fire on charging I would suggest sticking to recognised common brands using their correct charger. At least you know there are thousands like it in use with no fires. Even so I would not leave a charger on over night or unattended and on the boat just do enough recharge to meet your needs. If at all possible (at home) charge in a place on a surface where battery fire might be less catastrophic.
Yes I might be OTT regarding safety here as there are just so many millions of lithium batteries being charged every day. Of course there are other more efficient options than an inverter for charging like 18v batteries from 12v but you may be going into a less popular non standard charger which may increase risk.
However if you go inverter you must always be aware of power consumption of any device you might use. Beware 240v power tools have large current draw at start up, any deice with heating in it, microwave oven and 240v vacuum cleaner. ol'will
Alan S
Well-Known Member
OP just wants a simple way of using 12V tools on board. I think my suggestion of running them direct from the boat's 12V supply is by far the best, simplest, safest and cheapest way to do this.
PaulRainbow
Well-Known Member
I think you are mistaken Alan, this isn't a good plan with Lithium batteries.
Kelpie
Well-Known Member
If he's running the tool strictly from the boat's own batteries, there is no lithium involved.
Of course with an 18v tool, as most lithium powered tools are, it's probably not going to work so well.
Alan S
Well-Known Member
No lithium batteries involved, Paul. Just wire the 12 V tool minus it's battery straight to the boat's system.
Refueler
Well-Known Member
If running direct from 12v - why would the old battery be fitted ? Guy was saying power the tool direct from 12v - discard the battery.
Refueler
Well-Known Member
OK ... I've shown this before and maybe worth repeating.
Many portable tools after a while - because most people just keep charging and want tool ready on demand - the battery packs suffer short lives. What to do ? Buy another pack ?
There are three ways to attack this ...
1. Pay silly money for a new battery pack
2. Connect a trailing lead for direct connection to boat / car battery
3. Swap old battery pack for different similar voltage pack you can charge
I usually go for #2 and #3.
With #2 - I usually still have the old battery fitted - but I cut or insulate the contacts to prevent the battery getting power from the lead. Why ? Because most hand tool are better balanced that way ... without the weight of battery they are usually very top heavy.
With #3 - I have quite a few 'tired' LiPo packs that I no longer use in high power demand models. Many modekls are pulling 20 ... 30 .. 50A and that is usually a lot more than a hand drill needs. So those tired LiPo's can still give useful life in drills ... torches ... various.
Here's a drill having battery replaced by me :
It may be of interest - that when replacing a 12v NiCd / NiMh pack - you can in fact get 12v SLA small enough to replace it with ... then charging is much easier from a wall adaptor used for many 12v hand gear ... or in the car ciggy socket etc.
Many portable tools after a while - because most people just keep charging and want tool ready on demand - the battery packs suffer short lives. What to do ? Buy another pack ?
There are three ways to attack this ...
1. Pay silly money for a new battery pack
2. Connect a trailing lead for direct connection to boat / car battery
3. Swap old battery pack for different similar voltage pack you can charge
I usually go for #2 and #3.
With #2 - I usually still have the old battery fitted - but I cut or insulate the contacts to prevent the battery getting power from the lead. Why ? Because most hand tool are better balanced that way ... without the weight of battery they are usually very top heavy.
With #3 - I have quite a few 'tired' LiPo packs that I no longer use in high power demand models. Many modekls are pulling 20 ... 30 .. 50A and that is usually a lot more than a hand drill needs. So those tired LiPo's can still give useful life in drills ... torches ... various.
Here's a drill having battery replaced by me :
It may be of interest - that when replacing a 12v NiCd / NiMh pack - you can in fact get 12v SLA small enough to replace it with ... then charging is much easier from a wall adaptor used for many 12v hand gear ... or in the car ciggy socket etc.
