DIY Forum

 

Ultimate HandymanUltimate Handyman on Pinterest

 

DIY Forum/Home improvement advice forum

 

 

A-Z CONTENTS | DISCLAIMER | DIY VIDEO | HOME | SAFETY FIRST | FORUM RULES

It is currently Wed Nov 14, 2018 1:30 pm
Visit Hilti


Time zone: Europe/London




 

 


Post new topic Reply to topic  [ 12 posts ] 
Author Message
PostPosted: Wed Jul 11, 2018 12:44 pm 
Offline
Senior Member
User avatar

Joined: Wed May 14, 2014 2:38 pm
Posts: 412
Location: Derbyshire
Has thanked: 86 times
Been thanked: 58 times
My new chargers are classed by makita as 'fast' chargers; they have a charge time (for 5.0Ah) of 45mins, which is nearly 2.5x the rate of their 'standard' charger. That is exactly what I want for some applications, and much faster than I'm used to.

But.. we know that high charge rate (not just discharge rate) affects battery longevity. Very often (probably most often) I could get away with charging at the 'standard' rate if there were good enough reason.

Yet.. 45mins is still about three times more gentle than the worst of my tools will discharge at, so isn't extreme by any means; not sure if it is fast enough to even worry about. Does anyone think its worth getting additional standard rate chargers for use when speed is unimportant? (they cost around £25 each, but I'd need at least a couple).

Thanks

_________________
Kev


Share on FacebookShare on TwitterShare on DiggShare on DeliciousShare on Google+
Top
 Profile  
Reply with quote  
PostPosted: Wed Jul 11, 2018 6:57 pm 
Offline
Senior Member
User avatar

Joined: Mon Mar 15, 2010 11:49 pm
Posts: 10085
Location: Oban
Has thanked: 340 times
Been thanked: 1788 times
Well given that the only people to 'really' benefit from fast charging are the people that sell the batteries......

If you have a theoretical lifespan for the battery of 500 charge/discharge cycles and fast charging reduces that by (say) 20% will you be concerned for having a battery that only lasts 400 cycles?????

_________________
sent from my laptop using my fingers - because we REALLY need to know where it's come from.....


Top
 Profile  
Reply with quote  
PostPosted: Wed Jul 11, 2018 9:15 pm 
Offline
Old School Chippie
User avatar

Joined: Mon Sep 12, 2011 4:27 pm
Posts: 5862
Location: Lancashire
Has thanked: 741 times
Been thanked: 1485 times
In a word, no! Simply put Li-Ion batteries will deteriorate at 5 to 10% of their charge capacity for every year of their life - regardless of whether or not you use them. On top of that fast charging can reduce charge capacity a bit more. The question has to be, "just how long do you expect your batteries to last?". In trade use I'd say that everything over 3 years is a bonus and that that should be your target write-down time, as well as being a lifespan which will keep your batteries being within reasonable charge capacity. I'm afraid that when my 5Ah batteries get down to 70% (3.5Ah) capacity then that will be the time to transfer them to lighter duties, such as for DIY at home where 50% or even 30% of the original capacity won't make much difference. At work having to stop for 20 minutes or more while I walk down to the charge point and then return, maybe 3 times a day, is quickly going to cost me far more than the price of a few new batteries. With some of my 5Ah batteries now approaching 3 years maybe it's time I got the local Makita service dealer to do a battery test - what is certain is that they certainly don't give the same run time as long as my new batteries, although I haven't yet quantified the difference

_________________
"The person who never made a mistake, never made anything" - Albert Einstein

"I too will something make, And joy in the making" - Robert Bridges, 1844~1930



For this message the author Job and Knock has received gratitude : Kev888
Top
 Profile  
Reply with quote  
PostPosted: Wed Jul 11, 2018 10:22 pm 
Offline
Senior Member
User avatar

Joined: Wed May 14, 2014 2:38 pm
Posts: 412
Location: Derbyshire
Has thanked: 86 times
Been thanked: 58 times
Thanks both, those are exactly the kind of things I was trying to get a feel for.

Yes, after 3years the batteries could be down to about 75% capacity in any case, even having done very little. Though (as another thread suggested) they are less than a year old when I bought them, so hopefully I've got at least a couple of years before 5ah become <4ah through age alone. My experience with some that I used only occasionally (due to being small capacity) suggest maybe ~7%/yr deterioration or a tad less is about right.

So in comparison to the high discharge tools and the ageing thing, the difference between modest and higher charge speeds isn't going to be great. TBH i suspect having standard rate chargers over enough batteries and enough years would still see notable savings, but weighed against the inconvenience and cost of having to double up on chargers and extend charging time, I shall put the idea to bed.

Thanks again.

_________________
Kev


Top
 Profile  
Reply with quote  
PostPosted: Wed Jul 11, 2018 10:29 pm 
Online
Pro Carpenter
User avatar

Joined: Sat Dec 16, 2006 10:11 pm
Posts: 20778
Location: redhill surrey an auld reekie laddie
Has thanked: 694 times
Been thanked: 1979 times
if time and space are at a premium then having to transfer say 3 x5ah batts rather than 5 x5 ah may be a no brainer with the additional "running cost" having to replace your batts more often will be more than offset time and convenience wise

_________________
we are all ------------------still learning


Top
 Profile  
Reply with quote  
PostPosted: Wed Jul 11, 2018 10:47 pm 
Offline
Senior Member
User avatar

Joined: Wed May 14, 2014 2:38 pm
Posts: 412
Location: Derbyshire
Has thanked: 86 times
Been thanked: 58 times
Yes, I agree. The biggest factor for me was that fast chargers would allow continual working with about 6x batteries, whereas standard chargers would need double that number.

In my case its only going to be an occasional thing, to use batteries so heavily and continuously (which is why slow charging would so often be an option). But that makes doubling up on batteries even less desirable, given how they age when being lightly used normally.

_________________
Kev


Top
 Profile  
Reply with quote  
PostPosted: Wed Jul 11, 2018 11:02 pm 
Online
Pro Carpenter
User avatar

Joined: Sat Dec 16, 2006 10:11 pm
Posts: 20778
Location: redhill surrey an auld reekie laddie
Has thanked: 694 times
Been thanked: 1979 times
another point to note
cycling your batteries can give a bit more run time within the same day as in a battery will go "flat" in a high draw brushless tool but in actual fact have enough left for say a fan/driver/light for a few hours
so providing all batts are equally charged rather than plonk on charge swop first with a low draw tool making sure you have a spare fully charged battery in case :lol:
i mark all batteries and take note off batteries when they go flat which over time will tell you the best and worst batteries by number
another good thing about li-ions is you can plonk them on charge any time and short charge them
so you get on site with say 3 batts all fairly flat as you forgot to charge them :lol:
you dont need any down time till the charge cycle finishes you just take it off charge iff you need it placing another on charge when you do and hopefully can catch up as you go :lol:

_________________
we are all ------------------still learning



For this message the author big-all has received gratitude : Kev888
Top
 Profile  
Reply with quote  
PostPosted: Thu Jul 12, 2018 9:06 am 
Offline
Senior Member

Joined: Fri Oct 02, 2015 12:43 pm
Posts: 290
Location: France
Has thanked: 1 times
Been thanked: 41 times
Just a small point when in days past I used to race model boats and cars, we always ensured that the battery pack was fully discharged before we put them back on charge, this was done with a 12vlt car bulb with two wires soldered to it (+ - ) take the battery out of car/boat and connect to the bulb, that will then "drain" off any power left, when the bulb is out then re-charge the batteries. I assume it is the same today :dunno: Nos


Top
 Profile  
Reply with quote  
PostPosted: Thu Jul 12, 2018 9:32 am 
Online
Pro Carpenter
User avatar

Joined: Sat Dec 16, 2006 10:11 pm
Posts: 20778
Location: redhill surrey an auld reekie laddie
Has thanked: 694 times
Been thanked: 1979 times
Nos wrote:
Just a small point when in days past I used to race model boats and cars, we always ensured that the battery pack was fully discharged before we put them back on charge, this was done with a 12vlt car bulb with two wires soldered to it (+ - ) take the battery out of car/boat and connect to the bulb, that will then "drain" off any power left, when the bulb is out then re-charge the batteries. I assume it is the same today :dunno: Nos

quite different with li-ons :lol:
they have protection circuits to hold a small charge and stop them going flat because if they go flat thats it they are dead and will not charge

_________________
we are all ------------------still learning


Top
 Profile  
Reply with quote  
PostPosted: Thu Jul 12, 2018 6:16 pm 
Offline
Old School Chippie
User avatar

Joined: Mon Sep 12, 2011 4:27 pm
Posts: 5862
Location: Lancashire
Has thanked: 741 times
Been thanked: 1485 times
big-all wrote:
...so you get on site with say 3 batts all fairly flat as you forgot to charge them :lol:
you dont need any down time till the charge cycle finishes you just take it off charge iff you need it placing another on charge when you do and hopefully can catch up as you go :lol:

The issue of charging on site is always a contentious one. Where I'm currently working it can mean a 15 minute round trip to get from an un-powered work area area to the charger station then back again - always providing you are willing to leave batteries on charge with their charger(s) in an unsecured location (I'm not) - which makes having a day's worth of 5Ah batteries a no brainer. Sometimes I work where the power supply is relatively near, but over the past 5 years that's been the exception rather than the rule for me.

Nos wrote:
Just a small point when in days past I used to race model boats and cars, we always ensured that the battery pack was fully discharged before we put them back on charge.....

As B-A says, Li-Ion is a different beast altogether. In addition to his point manufacturers often recommend that it is more efficient (causes less degradation of the battery?) to recharge a battery when it is about 80% discharged than to deep discharge it. You are also advised to store Li-Ions fully charged if at all possible

_________________
"The person who never made a mistake, never made anything" - Albert Einstein

"I too will something make, And joy in the making" - Robert Bridges, 1844~1930


Top
 Profile  
Reply with quote  
PostPosted: Fri Jul 13, 2018 8:25 am 
Offline
Senior Member

Joined: Fri Oct 02, 2015 12:43 pm
Posts: 290
Location: France
Has thanked: 1 times
Been thanked: 41 times
Thanks guys it was ni-cads that were the "new" batteries in my day. Nos


Top
 Profile  
Reply with quote  
PostPosted: Sun Jul 15, 2018 8:14 pm 
Offline
Senior Member
User avatar

Joined: Sat Jan 10, 2009 3:49 pm
Posts: 24006
Location: hants/dorset border
Has thanked: 1503 times
Been thanked: 3801 times
Li-ions don't have the same "memory effect" as Ni-Cads.

_________________
Verwood Handyman

Verwood Handyman


___________________________________________________________________

If you feel you have benefited from the Free advice given on the Forum, Please consider making a donation to UHM's Nominated charity, read all about it and donate here :

http://www.donnasdreamhouse.co.uk/


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 12 posts ] 

 

 




Similar topics
   

Time zone: Europe/London


Who is online

Users browsing this forum: No registered users and 0 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Visit Solent plastics


 

 

 

News News Site map Site map SitemapIndex SitemapIndex RSS Feed RSS Feed Channel list Channel list
ultimatehandyman privacy policy

Contact

 

Powered by phpBB® Forum Software © phpBB Group

phpBB SEO