I've got a number of Bosch 36v (gardening) devices which use the same
36V battery. These are quite expensive (130 quid or so for a genuine 4ah
one). I was mowing my lawn recently and the mower just stopped
without warning.

Another battery works fine so it's the battery.

When I try to charge it an error light illuminates on the charger. Being a lithium battery it's got a quite complicated (looking) charge/discharge management circuit built into the battery. One of the inputs is a
thermistor (packed in the middle of the cells to measure the temperature)
which I've read can fail. I've tried to read the resistance (in situ) and it
seems to be open circuit.

Looking at the cell pack it seems to be assembled in four series groups of
cells, each group reads about 8v giving a lower total output of roughly 32v.
A good battery reads 40v when fully charged and with no load. The voltage
suggests it's just 'flat' rather than a single cell having gone bad. Maybe.

I can't find a circuit for the battery's BMS so don't have a clue what
thermistor I should use and I'm loathe to pull a good battery apart to swap
parts; killing a good battery trying to fix a dead one...

So, any smart ideas?

- Put a resistive load onto it and see if the terminal voltage drops
(suggesting a bad cell in the pack).

- Remove the thermistor and test it properly for resistance.

- Take a guess at the thermistor value and replace it with a 10k
resistor and see if the battery starts to charge, if so then I could just
get a 10k NTC thermistor and try that.

- Find a cheap second hand working (lower capacity) one
and rob the thermistor from that- pretty sure they'd be the same
across the range.

- *maybe* buy a cheap third party BMS and try to fit it into the cell
pack- but I suspect this is (probably) a little risky...

Any other suggestions?

Apart from 'just buy another battery you tight cunt' (I've already done this
but it's not really the point anymore).

Stephen Packer <stephen.packer@gmail.com> wrote in
news:18f3c6c0-2be1-4273-bd23-f580bb2b8c9en@googlegroups.com:

> Any other suggestions?
>
> Apart from 'just buy another battery you tight cunt' (I've already
> done this but it's not really the point anymore).
>

my colleagues at Xerox, when looking for that mystery low impedence would
just short out the thermistor with croc clips[1] and see what got warm

I would never have done such a thing of course.

Anyway, no flames? What have you done with Burnt?

[1] or more likely a pliers or a scredriver

On Thursday, 7 April 2022 at 18:10:39 UTC+1, wessie wrote:
> Stephen Packer <stephen...@gmail.com> wrote in
> news:18f3c6c0-2be1-4273...@googlegroups.com:
> > Any other suggestions?
> >
> > Apart from 'just buy another battery you tight cunt' (I've already
> > done this but it's not really the point anymore).
> >
> my colleagues at Xerox, when looking for that mystery low impedence would
> just short out the thermistor with croc clips[1] and see what got warm
>
> I would never have done such a thing of course.
>
> Anyway, no flames? What have you done with Burnt?

Heh. I spent about 5 years being responsible for all mobile phone failures
within a certain telco including battery failures. Especially worrying when
it was our own branded products. I developed a grudging respect for
lithium based batteries... Also, if the battery did 'vent' (never used
the word explode) it would probably damage the piece of equipment
it was connected to and that would result in further costs, so...

On 07/04/2022 18:10, wessie wrote:
> Stephen Packer <stephen.packer@gmail.com> wrote in
> news:18f3c6c0-2be1-4273-bd23-f580bb2b8c9en@googlegroups.com:
>
>
>> Any other suggestions?
>>
>> Apart from 'just buy another battery you tight cunt' (I've already
>> done this but it's not really the point anymore).
>>
>
> my colleagues at Xerox, when looking for that mystery low impedence would
> just short out the thermistor with croc clips[1] and see what got warm
>
> I would never have done such a thing of course.
>
> Anyway, no flames? What have you done with Burnt?
>
>
> [1] or more likely a pliers or a scredriver

Hmm. I wonder if the thermistor is PTC or NTC. Can't see shorting it out
at least for a short period to see if the charger recognises it would do
any/much harm.

--
/Simon

Stephen Packer <stephen.packer@gmail.com> wrote:
> I've got a number of Bosch 36v (gardening) devices which use the same
> 36V battery. These are quite expensive (130 quid or so for a genuine 4ah
> one). I was mowing my lawn recently and the mower just stopped
> without warning.
>
> Another battery works fine so it's the battery.
>
> When I try to charge it an error light illuminates on the charger.
> Being a lithium battery it's got a quite complicated (looking)
> charge/discharge management circuit built into the battery. One of
> the inputs is a thermistor (packed in the middle of the cells to
> measure the temperature) which I've read can fail. I've tried to
> read the resistance (in situ) and it > seems to be open circuit.
>
> Looking at the cell pack it seems to be assembled in four series groups of
> cells, each group reads about 8v giving a lower total output of roughly 32v.
> A good battery reads 40v when fully charged and with no load. The voltage
> suggests it's just 'flat' rather than a single cell having gone bad. Maybe.
>
> I can't find a circuit for the battery's BMS so don't have a clue what
> thermistor I should use and I'm loathe to pull a good battery apart to swap
> parts; killing a good battery trying to fix a dead one...
>
> So, any smart ideas?
>
> - Put a resistive load onto it and see if the terminal voltage drops
> (suggesting a bad cell in the pack).

I would try this. If you can measure across each cell group (as
you seem to indicate you can) you might find which one contains the
problematic individual cell(s) just from applying a load. The charger
may be reacting to a bad cell rather than the thermistor.

> - Remove the thermistor and test it properly for resistance.

I would also do this.

> - Take a guess at the thermistor value and replace it with a 10k
> resistor and see if the battery starts to charge, if so then I could just
> get a 10k NTC thermistor and try that.

This gets my vote. I'd try 10k first then go up / down to see what
the charger thinks.

--
FJR1300A, GL1000, KLR650A6F, EX250J9A, DR200SE, Vespa Ciao

On Thursday, 7 April 2022 at 18:41:56 UTC+1, siwilson wrote:

> Hmm. I wonder if the thermistor is PTC or NTC. Can't see shorting it out
> at least for a short period to see if the charger recognises it would do
> any/much harm.

From my googling they seem to generally be NTC. I'll keep it away from
any open cans of fuel or inflammable stuff as I mess around with it[1].

[1] Actually that's a complete lie- I know I *should* do this but it means tidying
my garages and despite having been essentially retired for roughly two and
a bit years I've not yet gotten around to this task... I built an overflow shed instead

On 07/04/2022 18:43, Mark Olson wrote:
> Stephen Packer <stephen.packer@gmail.com> wrote:
>> I've got a number of Bosch 36v (gardening) devices which use the same
>> 36V battery. These are quite expensive (130 quid or so for a genuine 4ah
>> one). I was mowing my lawn recently and the mower just stopped
>> without warning.
>>
>> Another battery works fine so it's the battery.
>>
>> When I try to charge it an error light illuminates on the charger.
>> Being a lithium battery it's got a quite complicated (looking)
>> charge/discharge management circuit built into the battery. One of
>> the inputs is a thermistor (packed in the middle of the cells to
>> measure the temperature) which I've read can fail. I've tried to
>> read the resistance (in situ) and it > seems to be open circuit.
>>
>> Looking at the cell pack it seems to be assembled in four series groups of
>> cells, each group reads about 8v giving a lower total output of roughly 32v.
>> A good battery reads 40v when fully charged and with no load. The voltage
>> suggests it's just 'flat' rather than a single cell having gone bad. Maybe.
>>
>> I can't find a circuit for the battery's BMS so don't have a clue what
>> thermistor I should use and I'm loathe to pull a good battery apart to swap
>> parts; killing a good battery trying to fix a dead one...
>>
>> So, any smart ideas?
>>
>> - Put a resistive load onto it and see if the terminal voltage drops
>> (suggesting a bad cell in the pack).
>
> I would try this. If you can measure across each cell group (as
> you seem to indicate you can) you might find which one contains the
> problematic individual cell(s) just from applying a load. The charger
> may be reacting to a bad cell rather than the thermistor.
>
>> - Remove the thermistor and test it properly for resistance.
>
> I would also do this.
>
>> - Take a guess at the thermistor value and replace it with a 10k
>> resistor and see if the battery starts to charge, if so then I could just
>> get a 10k NTC thermistor and try that.
>
> This gets my vote. I'd try 10k first then go up / down to see what
> the charger thinks.

Agreed, do all this but first, if you've already bought a
replacement/second battery, then why not have a look inside that and
measure its characteristics? Ie, measure its resistance at (say) 25degC
and then warm it slightly (in your hand?) to see if the value goes up or
down?

HTH, Chris

--
The Deuchars BBB#40 COFF#14
Yamaha XV750SE & Suzuki GS550t
http://www.Deuchars.org.uk

On Friday, 8 April 2022 at 11:09:56 UTC+1, ChrisND @UKRM wrote:

> Agreed, do all this but first, if you've already bought a
> replacement/second battery, then why not have a look inside that and
> measure its characteristics? Ie, measure its resistance at (say) 25degC
> and then warm it slightly (in your hand?) to see if the value goes up or
> down?

I don't want to open up a new battery and void the warranty.

I did *think* about doing it to an old battery though. However first
I stuck a load on the battery (old fashioned light bulb) and checked
the voltage across the cell sets. One set dropped significantly below the
others (to about 4.5v) and didn't really recover much. I suspect there's
a fucked cell in that group so the thermistor was a red herring.

Tempted to pull the pack apart and try to find the duff cell but I'd
have to buy one of those battery spot welders (which are surprisingly
cheap) and by the time I've done that... and bought replacement
cell/cells... I'm probably close to the cost of a new battery. Suppose
I can put it on the 'spares' pile...

On Thu, 7 Apr 2022 09:38:13 -0700 (PDT), Stephen Packer
<stephen.packer@gmail.com> wrote:

>Apart from 'just buy another battery you tight cunt' (I've already done this
>but it's not really the point anymore).

When I had an 18v battery die (from a Makita drill), I phoned my mate
Pat Sefton (known to a few here), who has run a workshop that
constructs wooden glamping 'pods' for at least the last 10 years, if
not more. The place employs 8~10 people, and they're all using
battery tools all day.

The charger for my Makita battery reported a problem with the battery,
like yours, and when I spoke to Pat about it, he said he'd fucked
about with dozens of similarly dead batteries over the years, and
eventually concluded that the success rate was so low, and the time
consumed so high, that the only thing to do was to suck it up and buy
a replacement.

For reference, Pat is at least as "careful"[1] with money as you are

Sorry

[1] i.e. tight
--
Champ
neal at champ dot org dot uk

I don't know, but I been told
You never slow down, you never grow old

On 08/04/2022 18:16, Champ wrote:
> On Thu, 7 Apr 2022 09:38:13 -0700 (PDT), Stephen Packer
> <stephen.packer@gmail.com> wrote:
>
>> Apart from 'just buy another battery you tight cunt' (I've already done this
>> but it's not really the point anymore).
>
> When I had an 18v battery die (from a Makita drill), I phoned my mate
> Pat Sefton (known to a few here), who has run a workshop that
> constructs wooden glamping 'pods' for at least the last 10 years, if
> not more. The place employs 8~10 people, and they're all using
> battery tools all day.
>
> The charger for my Makita battery reported a problem with the battery,
> like yours, and when I spoke to Pat about it, he said he'd fucked
> about with dozens of similarly dead batteries over the years, and
> eventually concluded that the success rate was so low, and the time
> consumed so high, that the only thing to do was to suck it up and buy
> a replacement.
>
> For reference, Pat is at least as "careful"[1] with money as you are
>
> Sorry
>
> [1] i.e. tight

That drill you bought 2 or 3 years ago? That sucks, I've not a Makita
battery die yet.

--
/Simon

On 08/04/2022 18:11, Stephen Packer wrote:
> On Friday, 8 April 2022 at 11:09:56 UTC+1, ChrisND @UKRM wrote:
>
>> Agreed, do all this but first, if you've already bought a
>> replacement/second battery, then why not have a look inside that and
>> measure its characteristics? Ie, measure its resistance at (say) 25degC
>> and then warm it slightly (in your hand?) to see if the value goes up or
>> down?
>
> I don't want to open up a new battery and void the warranty.
>
> I did *think* about doing it to an old battery though. However first
> I stuck a load on the battery (old fashioned light bulb) and checked
> the voltage across the cell sets. One set dropped significantly below the
> others (to about 4.5v) and didn't really recover much. I suspect there's
> a fucked cell in that group so the thermistor was a red herring.
>
> Tempted to pull the pack apart and try to find the duff cell but I'd
> have to buy one of those battery spot welders (which are surprisingly
> cheap) and by the time I've done that... and bought replacement
> cell/cells... I'm probably close to the cost of a new battery. Suppose
> I can put it on the 'spares' pile...

Gwan you know you want to
https://www.banggood.com/DIY-Portable-Battery-Storage-Spot-Welding-Machine-PCB-Circuit-Board-Welding-Equipment-Spot-Welders-for-18650-26650-12V-p-1646749.html?cur_warehouse=CZ

--
/Simon

On Fri, 08 Apr 2022 18:16:34 +0100, Champ <neal@champ.org.uk> wrote:

>The charger for my Makita battery reported a problem with the battery,
>like yours, and when I spoke to Pat about it, he said he'd fucked
>about with dozens of similarly dead batteries over the years, and
>eventually concluded that the success rate was so low, and the time
>consumed so high, that the only thing to do was to suck it up and buy
>a replacement.
>
>For reference, Pat is at least as "careful"[1] with money as you are
>
>Sorry

Heh.

These days I approach tools as almost disposable, buying cheapo stuff
from Lidl or similar for basics like screwdrivers, drills, small
circular saws etc. At 20-odd quid a go, it's just not worth thinking
about replacing batteries on them. Aklthough TBF I think the only
thing that the battery died on was a cheapo little leccy screwdriver.

Do they last as well as Makita et al? Probably not, but I do use them
a fair bit, although not at professional levels, with all the
renovations I've been doing here over the last few years.

>[1] i.e. tight

I'm so tight I still have the first B&D electric drill+accessories set
that was an engagement present, when I was about 19 or 20. It was
killed in a flood and replaced on the insurance, although continued to
function in one speed only so drove the sander, circular- and jig-saw
attatchments happily for many years.

Mebbe it's time to throw them out, it's not like they ever get used
these days, but you know...

--
Ace
http://www.chaletbeauroc.com/

On 07/04/2022 17:38, Stephen Packer wrote:
> I've got a number of Bosch 36v (gardening) devices which use the same
> 36V battery. These are quite expensive (130 quid or so for a genuine 4ah
> one). I was mowing my lawn recently and the mower just stopped
> without warning.
>
> Another battery works fine so it's the battery.
>
> When I try to charge it an error light illuminates on the charger. Being a lithium battery it's got a quite complicated (looking) charge/discharge management circuit built into the battery. One of the inputs is a
> thermistor (packed in the middle of the cells to measure the temperature)
> which I've read can fail. I've tried to read the resistance (in situ) and it
> seems to be open circuit.

Have you tried reading the resistance of the thermistor in a known good
battery?

On 08/04/2022 20:16, Ace wrote:
>
> I'm so tight I still have the first B&D electric drill+accessories set
> that was an engagement present, when I was about 19 or 20. It was
> killed in a flood and replaced on the insurance, although continued to
> function in one speed only so drove the sander, circular- and jig-saw
> attatchments happily for many years.
>
> Mebbe it's time to throw them out, it's not like they ever get used
> these days, but you know...

Not long after I moved to Tamworth in 1980, I entered a contest in the
local rag and won a B&D Quattro (somewhat different to the Audi of the
same name). I have found no reason to replace it over the intervening years.

Mike Fleming wrote:

> I entered a contest in the local rag and won a B&D Quattro

which seems to do drilling, jigsawing, sanding ... and ...

El Sat, 09 Apr 2022 02:16:21 +0100, Mike Fleming escribió:

> On 08/04/2022 20:16, Ace wrote:
>>
>> I'm so tight I still have the first B&D electric drill+accessories set
>> that was an engagement present, when I was about 19 or 20. It was
>> killed in a flood and replaced on the insurance, although continued to
>> function in one speed only so drove the sander, circular- and jig-saw
>> attatchments happily for many years.
>>
>> Mebbe it's time to throw them out, it's not like they ever get used
>> these days, but you know...
>
> Not long after I moved to Tamworth in 1980, I entered a contest in the
> local rag and won a B&D Quattro (somewhat different to the Audi of the
> same name). I have found no reason to replace it over the intervening
> years.

My Sealey 500 from around 81/82 is still going strong. I bought it off
the Snapon van. It's seen a LOT of action. I recently bought a new taper
chuck (someone here helped me out) and I think I may have changed the
brushes.

They don't make stuff like they used to...

--
Paul.

https://paulc.es/elpatio

On 08/04/2022 18:11, Stephen Packer wrote:
> On Friday, 8 April 2022 at 11:09:56 UTC+1, ChrisND @UKRM wrote:
>
>> Agreed, do all this but first, if you've already bought a
>> replacement/second battery, then why not have a look inside that and
>> measure its characteristics? Ie, measure its resistance at (say) 25degC
>> and then warm it slightly (in your hand?) to see if the value goes up or
>> down?
>
> I don't want to open up a new battery and void the warranty.
>
> I did *think* about doing it to an old battery though. However first
> I stuck a load on the battery (old fashioned light bulb) and checked
> the voltage across the cell sets. One set dropped significantly below the
> others (to about 4.5v) and didn't really recover much. I suspect there's
> a fucked cell in that group so the thermistor was a red herring.
>
> Tempted to pull the pack apart and try to find the duff cell but I'd
> have to buy one of those battery spot welders (which are surprisingly
> cheap) and by the time I've done that... and bought replacement
> cell/cells... I'm probably close to the cost of a new battery. Suppose
> I can put it on the 'spares' pile...

A (much cheaper) alternative to battery spot welding is to go and buy
some aluminium solder - that is a solder to join aluminium (and
incidentally, stainless steel) rather than one made of aluminium, I
hasten to add!

Use this, with the minimum amount of heat necessary, to put a blob of
said solder on the end of the battery in question. Do not try to solder
the wire on yet. Now, add a blob of conventional tin/lead solder to the
aluminium blob and solder the replacement wire onto this.

HTH. I used to do a lot of this stuff.

Chris D (Former professional bodger in electronics and engineering to
the research world)

--
The Deuchars BBB#40 COFF#14
Yamaha XV750SE & Suzuki GS550t
http://www.Deuchars.org.uk

On 08/04/2022 22:50, Mike Fleming wrote:
> On 07/04/2022 17:38, Stephen Packer wrote:
>> I've got a number of Bosch 36v (gardening) devices which use the same
>> 36V battery.  These are quite expensive (130 quid or so for a genuine 4ah
>>   one).  I was mowing my lawn recently and the mower just stopped
>> without warning.
>>
>> Another battery works fine so it's the battery.
>>
>> When I try to charge it an error light illuminates on the charger.
>> Being a lithium battery it's got a quite complicated (looking)
>> charge/discharge management circuit built into the battery.  One of
>> the inputs is a
>> thermistor (packed in the middle of the cells to measure the temperature)
>> which I've read can fail.  I've tried to read the resistance (in situ)
>> and it
>> seems to be open circuit.
>
> Have you tried reading the resistance of the thermistor in a known good
> battery?

Erm, I said that...
C --
The Deuchars BBB#40 COFF#14
Yamaha XV750SE & Suzuki GS550t
http://www.Deuchars.org.uk

On 07/04/2022 17:38, Stephen Packer wrote:
> I've got a number of Bosch 36v (gardening) devices which use the same
> 36V battery. These are quite expensive (130 quid or so for a genuine 4ah
> one). I was mowing my lawn recently and the mower just stopped
> without warning.
>
> Another battery works fine so it's the battery.
>
> When I try to charge it an error light illuminates on the charger. Being a lithium battery it's got a quite complicated (looking) charge/discharge management circuit built into the battery. One of the inputs is a
> thermistor (packed in the middle of the cells to measure the temperature)
> which I've read can fail. I've tried to read the resistance (in situ) and it
> seems to be open circuit.
>
> Looking at the cell pack it seems to be assembled in four series groups of
> cells, each group reads about 8v giving a lower total output of roughly 32v.
> A good battery reads 40v when fully charged and with no load. The voltage
> suggests it's just 'flat' rather than a single cell having gone bad. Maybe.
>
> I can't find a circuit for the battery's BMS so don't have a clue what
> thermistor I should use and I'm loathe to pull a good battery apart to swap
> parts; killing a good battery trying to fix a dead one...
>
> So, any smart ideas?
>
> - Put a resistive load onto it and see if the terminal voltage drops
> (suggesting a bad cell in the pack).
>
> - Remove the thermistor and test it properly for resistance.
>
> - Take a guess at the thermistor value and replace it with a 10k
> resistor and see if the battery starts to charge, if so then I could just
> get a 10k NTC thermistor and try that.
>
> - Find a cheap second hand working (lower capacity) one
> and rob the thermistor from that- pretty sure they'd be the same
> across the range.
>
> - *maybe* buy a cheap third party BMS and try to fit it into the cell
> pack- but I suspect this is (probably) a little risky...
>
> Any other suggestions?
>
> Apart from 'just buy another battery you tight cunt' (I've already done this
> but it's not really the point anymore).

I've just had a quick look at Makita prices. They seem to have gone up
quite a lot. A 5Ah 18v battery is over 70 quid now :(

--
/Simon

On Fri, 8 Apr 2022 18:31:43 +0100, siwilson
<siwilson@nodamnspam.hotmail.com> wrote:

>On 08/04/2022 18:16, Champ wrote:

>> When I had an 18v battery die (from a Makita drill)

>That drill you bought 2 or 3 years ago?

yeah

>That sucks, I've not a Makita battery die yet.

<shrug> Prolly didn't get used enough
--
Champ
neal at champ dot org dot uk

I don't know, but I been told
You never slow down, you never grow old

On 11/04/2022 18:58, Ace wrote:
> On Mon, 11 Apr 2022 18:51:21 +0100, Champ <neal@champ.org.uk> wrote:
>
>> On Fri, 8 Apr 2022 18:31:43 +0100, siwilson
>> <siwilson@nodamnspam.hotmail.com> wrote:
>>
>>> On 08/04/2022 18:16, Champ wrote:
>>
>>>> When I had an 18v battery die (from a Makita drill)
>>
>>> That drill you bought 2 or 3 years ago?
>>
>> yeah
>>
>>> That sucks, I've not a Makita battery die yet.
>>
>> <shrug> Prolly didn't get used enough
>
> I was wondering if there's a 'best' regime for charging these things.
> Back in the days of NiCads there was a lot of talk about memory
> effect, such that a full discharge was recommended from time to time,
> and continually recharging from half-charge was a bad thing. Does any
> such thing exist with the modern battery packs? Could lying unused for
> a long time kill the battery, or would simply leaving it permanently
> on charge be a bad thing?
>

I believe lithium type chemistry you're not supposed to keep them fully
charged. The fancy batteries on eg my drone have a built in monitoring
system that will discharge them to a certain level if you leave them too
long without using them. They definitely don't suffer from memory like
Nicads do. Lying unused for a long time in general should be ok as long
as they are not discharged too low. The Makita batteries don't have
anything built in them to stop this - they rely on the tool that is
using them to switch off before that happens.

--
/Simon

On 4/11/2022 11:22 AM, siwilson wrote:
> On 11/04/2022 18:58, Ace wrote:
>> On Mon, 11 Apr 2022 18:51:21 +0100, Champ <neal@champ.org.uk> wrote:
>>
>>> On Fri, 8 Apr 2022 18:31:43 +0100, siwilson
>>> <siwilson@nodamnspam.hotmail.com> wrote:
>>>
>>>> On 08/04/2022 18:16, Champ wrote:
>>>
>>>>> When I had an 18v battery die (from a Makita drill)
>>>
>>>> That drill you bought 2 or 3 years ago?
>>>
>>> yeah
>>>
>>>> That sucks, I've not a Makita battery die yet.
>>>
>>> <shrug>  Prolly didn't get used enough
>>
>> I was wondering if there's a 'best' regime for charging these things.
>> Back in the days of NiCads there was a lot of talk about memory
>> effect, such that a full discharge was recommended from time to time,
>> and continually recharging from half-charge was a bad thing. Does any
>> such thing exist with the modern battery packs? Could lying unused for
>> a long time kill the battery, or would simply leaving it permanently
>> on charge be a bad thing?
>>
>
> I believe lithium type chemistry you're not supposed to keep them fully
> charged. The fancy batteries on eg my drone have a built in monitoring
> system that will discharge them to a certain level if you leave them too
> long without using them. They definitely don't suffer from memory like
> Nicads do. Lying unused for a long time in general should be ok as long
> as they are not discharged too low. The Makita batteries don't have
> anything built in them to stop this - they rely on the tool that is
> using them to switch off before that happens.
>
I don't remember what kind of battery my BMW-GS uses, but Stefan, the
storer, wants me to get a new one. It's just been sitting there for
almost 3 years. I think it should be OK, but he's going to replace it
anyway. He's gotta make money somehow.

--
The erstwhile Thomas
FJR1300, R1200GS, ST1100 (in memoriam)

On Mon, 11 Apr 2022 11:39:40 -0700, Turby <xsurf@xmail.com> wrote:

>I don't remember what kind of battery my BMW-GS uses,

I imagine it would be a gel lead-acid one, no? I replaced the one in
my ride-on mower a few years ago, having got through several more
traditional lead-acid ones that died from lack of use/charging over
several winters. The latest one holds charge for months and has lasted
me about five years so far with minimal recharging required. It
started fine a couple of weeks ago, having been unused since October.

--
Ace
http://www.chaletbeauroc.com/

Turby <xsurf@xmail.com> wrote in news:t31sld$t88$1@dont-email.me:

> I don't remember what kind of battery my BMW-GS uses, but Stefan, the
> storer, wants me to get a new one. It's just been sitting there for
> almost 3 years. I think it should be OK, but he's going to replace it
> anyway. He's gotta make money somehow.
>

the OEM battery is an Exide AGM - assuming the bike has had at least one
change of battery, it will almost certainly have another AGM battery. Most
likely an Exide but it is a generic size made by Varta, Yuasa. About �40 in
the UK from an online supplier.
https://www.tayna.co.uk/motorcycle-batteries/exide/etx14-bs/

AGM really do not like to be deep discharged but they last a long time if
used often or kept topped up. My 2106 R1200RS uses the same battery and is
still using the original. This battery is bound to fail in France now, on a
Sunday or Monday when all bike shops are closed. I carry a jump start pack.

Does Stefan not have the bike on a maintenance charger for that fee he
charges you?

On 4/11/2022 12:40 PM, wessie wrote:
> Turby <xsurf@xmail.com> wrote in news:t31sld$t88$1@dont-email.me:
>
>
>> I don't remember what kind of battery my BMW-GS uses, but Stefan, the
>> storer, wants me to get a new one. It's just been sitting there for
>> almost 3 years. I think it should be OK, but he's going to replace it
>> anyway. He's gotta make money somehow.
>>
>
> the OEM battery is an Exide AGM - assuming the bike has had at least one
> change of battery, it will almost certainly have another AGM battery. Most
> likely an Exide but it is a generic size made by Varta, Yuasa. About Ł40 in
> the UK from an online supplier.
> https://www.tayna.co.uk/motorcycle-batteries/exide/etx14-bs/
>
> AGM really do not like to be deep discharged but they last a long time if
> used often or kept topped up. My 2106 R1200RS uses the same battery and is
> still using the original. This battery is bound to fail in France now, on a
> Sunday or Monday when all bike shops are closed. I carry a jump start pack.
>
> Does Stefan not have the bike on a maintenance charger for that fee he
> charges you?

He does, and that's another reason I think it should work. I think he's
just discovered a way to make more money.

--
The erstwhile Thomas
FJR1300, R1200GS, ST1100 (in memoriam)