I'm trying out a 120w inverter in the van, the idea being to charge drill 
batteries on the move.

The charger is a Makita 7.2 to 14.4v 30 minute jobby.  Problem is I rarely 
drive for more than about 15 mins from job to job.

I understand that the Makita charger is 'intelligent' in that it will cope 
with partly discharged batteries & not over charge them.

Will charging a battery for say 3 x 10 minute periods rather than 1 x 30 min 
period cause damage to the batteries or shorten their life?


-- 
Dave - The Medway Handyman
www.medwayhandyman.co.uk

The Medway Handyman wrote:
> I'm trying out a 120w inverter in the van, the idea being to charge drill 
> batteries on the move.
> 
> The charger is a Makita 7.2 to 14.4v 30 minute jobby.  Problem is I rarely 
> drive for more than about 15 mins from job to job.
> 
> I understand that the Makita charger is 'intelligent' in that it will cope 
> with partly discharged batteries & not over charge them.
> 
> Will charging a battery for say 3 x 10 minute periods rather than 1 x 30 min 
> period cause damage to the batteries or shorten their life?
> 
> 
most intelligent chargers employ a delta peak cut off so charging in 
batches should make no difference, your other option is a radio control 
model charger running directly off of 12V

-- 
Kevin R
Reply address works

In article <UMVuk.51296$E41.46508@text.news.virginmedia.com>,
   The Medway Handyman  wrote:
> I'm trying out a 120w inverter in the van, the idea being to charge
> drill batteries on the move.

> The charger is a Makita 7.2 to 14.4v 30 minute jobby.  Problem is I
> rarely drive for more than about 15 mins from job to job.

> I understand that the Makita charger is 'intelligent' in that it will
> cope with partly discharged batteries & not over charge them.

> Will charging a battery for say 3 x 10 minute periods rather than 1 x 30
> min period cause damage to the batteries or shorten their life?

As long as it doesn't discharge batteries to a preset level at switch on
you should be ok.

-- 
*It sounds like English, but I can't understand a word you're saying. 

    Dave Plowman        dave@davenoise.co.uk           London SW
                  To e-mail, change noise into sound.

Dave Plowman (News) wrote:
> In article <UMVuk.51296$E41.46508@text.news.virginmedia.com>,
>   The Medway Handyman  wrote:
>> I'm trying out a 120w inverter in the van, the idea being to charge
>> drill batteries on the move.
>
>> The charger is a Makita 7.2 to 14.4v 30 minute jobby.  Problem is I
>> rarely drive for more than about 15 mins from job to job.
>
>> I understand that the Makita charger is 'intelligent' in that it will
>> cope with partly discharged batteries & not over charge them.
>
>> Will charging a battery for say 3 x 10 minute periods rather than 1
>> x 30 min period cause damage to the batteries or shorten their life?
>
> As long as it doesn't discharge batteries to a preset level at switch
> on you should be ok.

Thanks Dave - but how would I know?


-- 
Dave - The Medway Handyman
www.medwayhandyman.co.uk

"The Medway Handyman"  wrote:

>I'm trying out a 120w inverter in the van, the idea being to charge drill 
>batteries on the move.
>
>The charger is a Makita 7.2 to 14.4v 30 minute jobby.  Problem is I rarely 
>drive for more than about 15 mins from job to job.
>
>I understand that the Makita charger is 'intelligent' in that it will cope 
>with partly discharged batteries & not over charge them.
>
>Will charging a battery for say 3 x 10 minute periods rather than 1 x 30 min 
>period cause damage to the batteries or shorten their life?


I don't know the answer to that question, but one possible solution is
to buy an additional battery of the "deep cycle" type, sometimes
called a "leisure" or "marine" battery.  They are used in caravans and
camper vans, so you should find it easy to install one in your van,
charged from the alternator by a "split charging circuit" which
ensures the main vehicle battery is always kept fully charged.  

You could then run the inverter directly from the deep cycle battery,
leaving it on all the time.  Unlike a normal car or van battery, the
deep cycle battery will tolerate deep discharging (hence its name) so
you have no worries about leaving it on.  

When the van's engine is running, both the van battery and the deep
cycle battery will be recharged, with the van battery always having
priority thanks to the split charging circuit.

Deep cycle batteries generally cost about 50% more than a similarly
sized car or van battery.  You can buy a split charging relay on eBay
from around £20.  There are kits for vans such as Transit, Ducato etc.

"The Medway Handyman"  wrote in message 
news:UMVuk.51296$E41.46508@text.news.virginmedia.com...
> I'm trying out a 120w inverter in the van, the idea being to charge drill 
> batteries on the move.
>
> The charger is a Makita 7.2 to 14.4v 30 minute jobby.  Problem is I rarely 
> drive for more than about 15 mins from job to job.
>
> I understand that the Makita charger is 'intelligent' in that it will cope 
> with partly discharged batteries & not over charge them.
>
> Will charging a battery for say 3 x 10 minute periods rather than 1 x 30 
> min period cause damage to the batteries or shorten their life?

I would be inclined to be sceptical - we took an inverter on holiday with us 
once when we had a camera which used a Li-ion cell and needed a 'mains to 
7v' charger. It may have coincided with the cell getting old, but I noticed 
that the camera held its charge much less after that holiday.

Bruce wrote:
> "The Medway Handyman"  wrote:
> 
>> I'm trying out a 120w inverter in the van, the idea being to charge drill 
>> batteries on the move.
>>
>> The charger is a Makita 7.2 to 14.4v 30 minute jobby.  Problem is I rarely 
>> drive for more than about 15 mins from job to job.
>>
>> I understand that the Makita charger is 'intelligent' in that it will cope 
>> with partly discharged batteries & not over charge them.
>>
>> Will charging a battery for say 3 x 10 minute periods rather than 1 x 30 min 
>> period cause damage to the batteries or shorten their life?
> 
> 
> I don't know the answer to that question, but one possible solution is
> to buy an additional battery of the "deep cycle" type, sometimes
> called a "leisure" or "marine" battery.  They are used in caravans and
> camper vans, so you should find it easy to install one in your van,
> charged from the alternator by a "split charging circuit" which
> ensures the main vehicle battery is always kept fully charged.  
> 
> You could then run the inverter directly from the deep cycle battery,
> leaving it on all the time.  Unlike a normal car or van battery, the
> deep cycle battery will tolerate deep discharging (hence its name) so
> you have no worries about leaving it on.  
> 
> When the van's engine is running, both the van battery and the deep
> cycle battery will be recharged, with the van battery always having
> priority thanks to the split charging circuit.
> 
> Deep cycle batteries generally cost about 50% more than a similarly
> sized car or van battery.  You can buy a split charging relay on eBay
> from around £20.  There are kits for vans such as Transit, Ducato etc.
> 
>  
most inverters have a cut of that stops them working below a certain 
voltage to prevent deep discharge

-- 
Kevin R
Reply address works

On 1 Sep, 18:39, "The Medway Handyman"
 wrote:
> I'm trying out a 120w inverter in the van, the idea being to charge drill
> batteries on the move.



So your inverter will change the van's DC to AC so that the drill's
charger
can change the AC back to DC. Surely there must be a simpler solution?

Mr Fuxit wrote:
> On 1 Sep, 18:39, "The Medway Handyman"
>  wrote:
>> I'm trying out a 120w inverter in the van, the idea being to charge
>> drill batteries on the move.
>
>
>
> So your inverter will change the van's DC to AC so that the drill's
> charger
> can change the AC back to DC. Surely there must be a simpler solution?

Mad I know, but I don't know another way to do it?


-- 
Dave - The Medway Handyman
www.medwayhandyman.co.uk

The Medway Handyman wrote:
> Mr Fuxit wrote:
>> On 1 Sep, 18:39, "The Medway Handyman"
>>  wrote:
>>> I'm trying out a 120w inverter in the van, the idea being to charge
>>> drill batteries on the move.
>>
>>
>> So your inverter will change the van's DC to AC so that the drill's
>> charger
>> can change the AC back to DC. Surely there must be a simpler solution?
> 
> Mad I know, but I don't know another way to do it?
> 
> 
if its a Nicd or NiMh then there are so many options, modellers have 
been using auto chargers for years, any model shop will sell you a 
similar charger to this one below all depends on the voltage of your 
drill how cheap you can get one for
http://alshobbies.com/shop/lookupstock.php?pc=5355&Desc=




-- 
Kevin R
Reply address works

On Mon, 01 Sep 2008 17:39:00 GMT, "The Medway Handyman"
 wrote:


>Will charging a battery for say 3 x 10 minute periods rather than 1 x 30 min 
>period cause damage to the batteries or shorten their life?

Possibly.  Most NiMH/NiCd fast chargers rely upon two charge limiting
mechanisms.  One, the primary one, detects a small depression in
voltage when charge is complete..  The second detects battery
temperature rise.   

Both depend upon a relatively stable environment. 
 In a van where the battery (and for cheap inverters) the inverter
voltage will vary and the temperature will also likely vary neither of
these may work any too well.  

The temperature rise is the most reliable - but by the time it is
detected the battery has been harmed to some degree.  Most dV (voltage
depression) detection fails when faced with intermittent charge
periods, varying environmental temperature and fluctuating and noisy
supply voltage.

Kevin  wrote:

>Bruce wrote:
>> "The Medway Handyman"  wrote:
>> 
>>> I'm trying out a 120w inverter in the van, the idea being to charge drill 
>>> batteries on the move.
>>>
>>> The charger is a Makita 7.2 to 14.4v 30 minute jobby.  Problem is I rarely 
>>> drive for more than about 15 mins from job to job.
>>>
>>> I understand that the Makita charger is 'intelligent' in that it will cope 
>>> with partly discharged batteries & not over charge them.
>>>
>>> Will charging a battery for say 3 x 10 minute periods rather than 1 x 30 min 
>>> period cause damage to the batteries or shorten their life?
>> 
>> 
>> I don't know the answer to that question, but one possible solution is
>> to buy an additional battery of the "deep cycle" type, sometimes
>> called a "leisure" or "marine" battery.  They are used in caravans and
>> camper vans, so you should find it easy to install one in your van,
>> charged from the alternator by a "split charging circuit" which
>> ensures the main vehicle battery is always kept fully charged.  
>> 
>> You could then run the inverter directly from the deep cycle battery,
>> leaving it on all the time.  Unlike a normal car or van battery, the
>> deep cycle battery will tolerate deep discharging (hence its name) so
>> you have no worries about leaving it on.  
>> 
>> When the van's engine is running, both the van battery and the deep
>> cycle battery will be recharged, with the van battery always having
>> priority thanks to the split charging circuit.
>> 
>> Deep cycle batteries generally cost about 50% more than a similarly
>> sized car or van battery.  You can buy a split charging relay on eBay
>> from around £20.  There are kits for vans such as Transit, Ducato etc.
>> 
>>  
>most inverters have a cut of that stops them working below a certain 
>voltage to prevent deep discharge


Thank you for that, but it doesn't in any way affect the sheer
brilliance of my idea.  ;-)

Mr Fuxit  wrote:

>On 1 Sep, 18:39, "The Medway Handyman"
> wrote:
>> I'm trying out a 120w inverter in the van, the idea being to charge drill
>> batteries on the move.
>
>
>
>So your inverter will change the van's DC to AC so that the drill's
>charger
>can change the AC back to DC. Surely there must be a simpler solution?


Not if the voltage of the Makita battery is greater than 12?

Bruce wrote:
> Mr Fuxit  wrote:
> 
>> On 1 Sep, 18:39, "The Medway Handyman"
>>  wrote:
>>> I'm trying out a 120w inverter in the van, the idea being to charge drill
>>> batteries on the move.
>>
>>
>> So your inverter will change the van's DC to AC so that the drill's
>> charger
>> can change the AC back to DC. Surely there must be a simpler solution?
> 
> 
> Not if the voltage of the Makita battery is greater than 12?
> 
there are plenty of 12v chargers that will charge a battery of more than 12v

-- 
Kevin R
Reply address works

In article <lSWuk.51355$E41.43012@text.news.virginmedia.com>,
   The Medway Handyman  wrote:
> Dave Plowman (News) wrote:
> > In article <UMVuk.51296$E41.46508@text.news.virginmedia.com>,
> >   The Medway Handyman  wrote:
> >> I'm trying out a 120w inverter in the van, the idea being to charge
> >> drill batteries on the move.
> >
> >> The charger is a Makita 7.2 to 14.4v 30 minute jobby.  Problem is I
> >> rarely drive for more than about 15 mins from job to job.
> >
> >> I understand that the Makita charger is 'intelligent' in that it will
> >> cope with partly discharged batteries & not over charge them.
> >
> >> Will charging a battery for say 3 x 10 minute periods rather than 1
> >> x 30 min period cause damage to the batteries or shorten their life?
> >
> > As long as it doesn't discharge batteries to a preset level at switch
> > on you should be ok.

> Thanks Dave - but how would I know?

The only Makita charger I have has a LED which flashes in different ways
to tell you what's going on. The graphics aren't that clear so you might
have to refer to the instruction book to see what they actually mean.

-- 
*Why do the two "sanction"s (noun and verb) mean opposites?*

    Dave Plowman        dave@davenoise.co.uk           London SW
                  To e-mail, change noise into sound.

Dave Plowman (News) wrote:
> In article <lSWuk.51355$E41.43012@text.news.virginmedia.com>,
>   The Medway Handyman  wrote:
>> Dave Plowman (News) wrote:
>>> In article <UMVuk.51296$E41.46508@text.news.virginmedia.com>,
>>>   The Medway Handyman  wrote:
>>>> I'm trying out a 120w inverter in the van, the idea being to charge
>>>> drill batteries on the move.
>>>
>>>> The charger is a Makita 7.2 to 14.4v 30 minute jobby.  Problem is I
>>>> rarely drive for more than about 15 mins from job to job.
>>>
>>>> I understand that the Makita charger is 'intelligent' in that it
>>>> will cope with partly discharged batteries & not over charge them.
>>>
>>>> Will charging a battery for say 3 x 10 minute periods rather than 1
>>>> x 30 min period cause damage to the batteries or shorten their
>>>> life?
>>>
>>> As long as it doesn't discharge batteries to a preset level at
>>> switch on you should be ok.
>
>> Thanks Dave - but how would I know?
>
> The only Makita charger I have has a LED which flashes in different
> ways to tell you what's going on. The graphics aren't that clear so
> you might have to refer to the instruction book to see what they
> actually mean.

Yup mine has various LED's which are 'on' or 'flash', what prompted me to 
ask was that mine had an LED signal warning that the battery was 
overheating.


-- 
Dave - The Medway Handyman
www.medwayhandyman.co.uk

Kevin  wrote:

>Bruce wrote:
>> Mr Fuxit  wrote:
>> 
>>> On 1 Sep, 18:39, "The Medway Handyman"
>>>  wrote:
>>>> I'm trying out a 120w inverter in the van, the idea being to charge drill
>>>> batteries on the move.
>>>
>>>
>>> So your inverter will change the van's DC to AC so that the drill's
>>> charger
>>> can change the AC back to DC. Surely there must be a simpler solution?
>> 
>> 
>> Not if the voltage of the Makita battery is greater than 12?
>> 
>there are plenty of 12v chargers that will charge a battery of more than 12v


So there's even less of a problem?  

Thanks, things just get better and better!

We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "The Medway Handyman"
 saying something like:

>I'm trying out a 120w inverter in the van, the idea being to charge drill 
>batteries on the move.
>
>The charger is a Makita 7.2 to 14.4v 30 minute jobby.  Problem is I rarely 
>drive for more than about 15 mins from job to job.

There is a Makita charger that runs off 12V - costs a bit, mind.
-- 
Dave
GS850x2 XS650 SE6a

"It's a moron working with power tools.
 How much more suspenseful can you get?"
 - House

>  Problem is I rarely drive for more than about 15 mins from job to job.
>

The cigarette lighter socket in the 2 volkswagen vans I've owned isn't
switched with the ignition - continuous power available.

Obviously having a charger plugged in discharges the vehicle battery,
but not particularly rapidly.

Cordless tool chargers probably draw around 50W whilst charging (for
say 30 minutes) - the equivalent of one headlight. Most modern
vehicles with a good condition battery, you could leave the headlights
on all day and still not adversely affect its starting.

So maybe consider having an unswitched cigarette lighter socket wired
in?

Bruce wrote:
> Kevin  wrote:
> 
>> Bruce wrote:
>>> Mr Fuxit  wrote:
>>>
>>>> On 1 Sep, 18:39, "The Medway Handyman"
>>>>  wrote:
>>>>> I'm trying out a 120w inverter in the van, the idea being to charge drill
>>>>> batteries on the move.
>>>>
>>>> So your inverter will change the van's DC to AC so that the drill's
>>>> charger
>>>> can change the AC back to DC. Surely there must be a simpler solution?
>>>
>>> Not if the voltage of the Makita battery is greater than 12?
>>>
>> there are plenty of 12v chargers that will charge a battery of more than 12v
> 
> 
> So there's even less of a problem?  
> 
> Thanks, things just get better and better!
> 
just look at different source of supplier you might need a bit of DIY to 
hook them up but they will work, I fast charge mine with a model 
car/plane charger 2 nails and a plastic g clamp, it auto cuts off and 
you can vary the charge rate to suit how quick you charge them

-- 
Kevin R
Reply address works

You might also like to look at the problem as an excuse to buy tools
with li-ion batteries, that don't mind partial charge and discharges.

I just bought this bundle from Bosch:

http://www.axminster.co.uk/product-Bosch-Lithium-Ion-Power-Kit-Li-Ion-10.8V-784434.htm

(my local Ridgeons has the same bundle for £222 incl vat)

In article <Yg%uk.51562$E41.30272@text.news.virginmedia.com>,
   The Medway Handyman  wrote:
> > The only Makita charger I have has a LED which flashes in different
> > ways to tell you what's going on. The graphics aren't that clear so
> > you might have to refer to the instruction book to see what they
> > actually mean.

> Yup mine has various LED's which are 'on' or 'flash', what prompted me
> to ask was that mine had an LED signal warning that the battery was
> overheating.

I'd doubt it. Decent chargers for yonks use a sensor in the battery to
prevent this - or other methods. I can't see the purpose of providing an
'overheat' warning when it is just as easy to prevent it. But presumably
you don't have the handbook to check?

Thing is what you're describing - an interruption to the power supply
while charging - is quite common on a building site, the home of such pro
tools. So I'd expect them to cater for it.

-- 
*Most people have more than the average number of legs*

    Dave Plowman        dave@davenoise.co.uk           London SW
                  To e-mail, change noise into sound.

dom@gglz.com  wrote:
> 
> Cordless tool chargers probably draw around 50W whilst charging (for
> say 30 minutes) - the equivalent of one headlight. Most modern
> vehicles with a good condition battery, you could leave the headlights
> on all day and still not adversely affect its starting.
> 
Headlights, all day, no I think not.  Two headlights are (as you say)
about 100 watts (to be exact they're probably 110 watts, but I won't
quibble).  If you left them on for 10 hours (a lot less than "all
day") they'd take something like 8 amps for 10 hours which is 80
ampere hours which is more than the capacity of most car batteries so
your battery would be fully discharged I'm afraid.

> So maybe consider having an unswitched cigarette lighter socket wired
> in?

-- 
Chris Green