Dewalt batteries black and yellow

[big-all]

all my batteries are 2-2.6ah and very old now but i have seven so not a big deal
its a fantastic tool and your mortar may be very soft and only use an average 100w but you get the idea the difference between a 2ah and a4ah is far less than twice the price and as you may get other tools to fit a better fuel cappacity will keep you working longer

 

[Restoration man]

I'll try it and see. It's a small detail job really. Worst case I'll buy a big battery.

That's the thing with all this technology you end up with an array of tools and then new battery's come out and there all worthless. I have a perfectly good makita combi drill that has battery's that don't hold a charge but the cost of battery's where so high I bought a new dewalt drill and moved on to lithium ion battery's. There great but I didn't think I needed them when I thought my nicad makita was great! Lol. They've got us.

To clarify above though are you saying a 4ah battery isn't better than two x 2ah batteries?

Thanks

 

[big-all]

if you are only getting 4ah capacity then 2x2 will give you less than half the run time compared to a 4h battery but one on charge and one in use will give you less down time but lots more climbing
a 4ah will last perhaps nearly 3 times longer than a single 2ah but with down time whilst it charges

the point is iff you plan lots off use some heavy use and quite a few tools in the future the 2x4ah batteries as a minimum
if only one heavy job then not much more with maybe 1 or 2 more tools then 2x2ah would be better
what other jobs and tools you thinking off

 

[Restoration man]

I am restoring an old house and do a mix of trades. I only get in a plumber but even then I do all the ****ty work first. Cordless I use drill impact drill and angle drill. Never any problems with power or run time. Nearly all other tools are 240v and in the garage. Table saw bench sander etc.

The grinder has come about as my house design is very awkward. Chimneys high out from the roof pitched dormers etc so I use scaffolding. Last time I did the chimneys at the other side of the house I used my makita 240v angle grinder. Works perfectly but cables and long extensions everywhere which you have to tether and secure. Thought this time I'd go cordless thinking buy a bare dewalt grinder use my existing batteries save a stack of time job done. It would then mean I'd have a portable grinder for the odd quick job if needed in future.

Although from our chat here it's not that simple.

I had thought ah was just simple maths 4ah would last the same time as two 2ah etc

 

[big-all]

just remember there are so many variables but in general a battery will loose perhaps between 10-25% off its capacity every year dependent on quality and use
how old are your batteries ??

 

[Restoration man]

My batteries are about 3 years old. They have never been hard used like tradespeople would do constantly on charge or being used. My work has mostly been weekends. They seem fine in the drills and last a long time. But like you've said in a high load tool like a grinder it might be different.

 

[big-all]

batteries can often be about for a year or so old before being sold they can still loose capacity without being used
the actual date off manufacture will probably be "stamped" in the plastic in the area on the top hidden by the tool body sometimes easier to read iff you rub a pencil over a yellow stamping or a coloured crayon if black
it will also say mexico/japan /romania/prc or where ever it was made

 

[Deleted member 174758]

I have an old Makita BGA451 18 volt cordless grinder which is used with older 3Ah batteries. For small tasks it is perfectly adequate, but you'd never do an entire gable end with it (at least not without swapping batteries). Our pipeline fitters use the same tool on 1.5Ah batteries but it's only in use sporadically to cut 15 or 22mm steel pipe - and for that it copes well enough. Battery tools are sensitive to the cutters used, so stick to the thinnest disc which will do the job. Only you can gauge how big a battery (in amps) you'll need, but for anything approaching heavy use 3Ah is really the minimum.

On the subject of battery life, Li-Ions have a finite life. They seem to lose 5 to 10% of their power capacity every year regardless of usage, charging pattern, etc. For a tradesman who'll consider 5 years as a reasonable lifetime for batteries (or should do) this isn't an issue. For a DIYer. though, I have started to wonder whether of not Li-Ion is a better technology or not.

 

[big-all]

yes its possible li-ions loose less capacity my 10-25% comments where for nicads

my brother actually has a charger that supposedly tells you the capacity off a fully charged random single battery and a lap top cell freed up from a pack off at least 6 years old the pack was 2.2ah and the single cell managed over 2ah but off course the accuracy off the charger would have to be checked to vouch for the accuracy
i was very sceptical off the accuracy knowing a 10-25% loss but iff li-ions can be around 5% that would work just about but even that would drop it to around 1.7ah after 5-6 years