Split charge for dynamo?

May be a silly question, but is it possible to wire up a split charge relay
for a second battery to a dynamo system in the same way as with an
alternator? I can't see any reason why not, but I've never heard of it
being done.

Series 2a 2¼ petrol.

TVMIA

--

Rich

Pas d'elle yeux Rhone que nous

On Wed, 29 Dec 2004 17:19:14 -0000, "Richard Brookman"
<[email protected]> wrote:

>May be a silly question, but is it possible to wire up a split charge relay
>for a second battery to a dynamo system in the same way as with an
>alternator? I can't see any reason why not, but I've never heard of it
>being done.
>

Given the output of the Lucas C40 being about 25 amps at best, I can't
see why you'd want to. In theory there's no reason why you can't, but
if you have that much potential load on the vehicle in the first place
you really should be considering an Alternator to keep up with the
vehicle and charging load in the first place.

Alex

So Alex was, like

> On Wed, 29 Dec 2004 17:19:14 -0000, "Richard Brookman"
> <[email protected]> wrote:
>
>> May be a silly question, but is it possible to wire up a split
>> charge relay for a second battery to a dynamo system in the same way
>> as with an alternator? I can't see any reason why not, but I've
>> never heard of it being done.
>>
>
> Given the output of the Lucas C40 being about 25 amps at best, I can't
> see why you'd want to. In theory there's no reason why you can't, but
> if you have that much potential load on the vehicle in the first place
> you really should be considering an Alternator to keep up with the
> vehicle and charging load in the first place.
>
> Alex

I know the dynamo output is low (I thought it was 20A), but I have a good
second battery hanging about (another story) and figured it might be a good
idea to add it to the system. Recently, a lot of my driving has been with
lights, wipers and blower on, and I reckoned the extra capacity would be
useful. An alternator (as well as some decent lighting) is on my shopping
list, but as the spare battery is already under the passenger seat I thought
it might be a useful addition for the sake of an hour's work.

Cheers

--

Rich

Pas d'elle yeux Rhone que nous

My 2a has a second battery connected in parallel on a dynamo system. The
regulator has separate regulators for the two batteries so a split
charge isn't necessary. I thought that was pretty standard for Lucas
regulators ...

Regards
Steve G

Richard Brookman wrote:
> So Alex was, like
>
>
>>On Wed, 29 Dec 2004 17:19:14 -0000, "Richard Brookman"
>><[email protected]> wrote:
>>
>>
>>>May be a silly question, but is it possible to wire up a split
>>>charge relay for a second battery to a dynamo system in the same way
>>>as with an alternator? I can't see any reason why not, but I've
>>>never heard of it being done.
>>>
>>

>
>> Given the output of the Lucas C40 being about 25 amps at best, I can't
>> see why you'd want to. In theory there's no reason why you can't, but
>> if you have that much potential load on the vehicle in the first place
>> you really should be considering an Alternator to keep up with the
>> vehicle and charging load in the first place.
>>
>> Alex
>
>I know the dynamo output is low (I thought it was 20A), but I have a good
>second battery hanging about (another story) and figured it might be a good
>idea to add it to the system. Recently, a lot of my driving has been with
>lights, wipers and blower on, and I reckoned the extra capacity would be
>useful. An alternator (as well as some decent lighting) is on my shopping
>list, but as the spare battery is already under the passenger seat I thought
>it might be a useful addition for the sake of an hour's work.
>

Depends if you've got the C39 or C40 fitted. The C39 is about 18 amps,
the C40 is about 25 (IIRC). Certainly if you want to go ahead with it,
then by all means, personally I'd just fit an alternator instead, I
already have a 110Ah battery under the bonnet anyway, which is a vast
improvement on the original spec battery.

Alex

So SteveG <"s.goodfellow"@blueyonder" < was, like

> My 2a has a second battery connected in parallel on a dynamo system.
> The regulator has separate regulators for the two batteries so a split
> charge isn't necessary. I thought that was pretty standard for Lucas
> regulators ...

>>>> May be a silly question, but is it possible to wire up a split
>>>> charge relay for a second battery to a dynamo system in the same
>>>> way as with an alternator? I can't see any reason why not, but
>>>> I've never heard of it being done.

Sounds just what I'm looking for. Would you mind letting me know how it's
wired up? Contact me off-group if necessary on richard dot brookman at
btinternet dot com.

Cheers

--

Rich

Pas d'elle yeux Rhone que nous

Richard Brookman wrote:

> So Alex was, like
>
>> On Wed, 29 Dec 2004 17:19:14 -0000, "Richard Brookman"
>> <[email protected]> wrote:
>>
>>> May be a silly question, but is it possible to wire up a split
>>> charge relay for a second battery to a dynamo system in the same way
>>> as with an alternator? I can't see any reason why not, but I've
>>> never heard of it being done.
>>>
>>
>> Given the output of the Lucas C40 being about 25 amps at best, I can't
>> see why you'd want to. In theory there's no reason why you can't, but
>> if you have that much potential load on the vehicle in the first place
>> you really should be considering an Alternator to keep up with the
>> vehicle and charging load in the first place.
>>
>> Alex
>
> I know the dynamo output is low (I thought it was 20A), but I have a good
> second battery hanging about (another story) and figured it might be a
> good
> idea to add it to the system. Recently, a lot of my driving has been with
> lights, wipers and blower on, and I reckoned the extra capacity would be
> useful. An alternator (as well as some decent lighting) is on my shopping
> list, but as the spare battery is already under the passenger seat I
> thought it might be a useful addition for the sake of an hour's work.
>
> Cheers
>
If you are thinking the extra battery will help with the extra load while
driving - it won't. All it will do is store extra energy, not make it. If
your battery is not keeping charged then fitting a second battery will
simply mean you have two batteries not keeping charged. In fact, the
situation may be worse, due to a slight loss of efficiency with a split
charging situation.
The only reason for a split charge system with two batteries is where you
are using power while NOT driving (such as winch, work lights, refrigerator
etc.), so that one battery can be kept for starting.
A major problem with a dynamo as opposed to an alternator is not the lower
rated output, but the fact that the dynamo outputs its rated power a lot
less of the time, as it has to be run at a lower speed relative to the
crankshaft (The windings on the alternator armature are circumferential
which means they are pretty much immune to centrifugal force, whereas the
windings on the dynamo armature include sections that are axial and rely on
varnish to keep them in place - alternators are geared to run at about
twice the speed of dynamos).
JD

Richard,

Sorry I haven't reponded before ... been a bit busy ;-)

I'll take a look at the circuit diagrams I inherited with the LR and see
what I come up with. I'm pretty certain that in amongst the box of bits
I got there's a spare regulator which was replaced but later found to be
good. Give me a couple of days ...

Regards
Steve G


Richard Brookman wrote:
> So SteveG <"s.goodfellow"@blueyonder" < was, like
>
>
>>My 2a has a second battery connected in parallel on a dynamo system.
>>The regulator has separate regulators for the two batteries so a split
>>charge isn't necessary. I thought that was pretty standard for Lucas
>>regulators ...
>
>
>>>>>May be a silly question, but is it possible to wire up a split
>>>>>charge relay for a second battery to a dynamo system in the same
>>>>>way as with an alternator? I can't see any reason why not, but
>>>>>I've never heard of it being done.
>
>
> Sounds just what I'm looking for. Would you mind letting me know how it's
> wired up? Contact me off-group if necessary on richard dot brookman at
> btinternet dot com.
>
> Cheers
>

So SteveG <"s.goodfellow"@blueyonder" < was, like

> Richard,
>
> Sorry I haven't reponded before ... been a bit busy ;-)
>
> I'll take a look at the circuit diagrams I inherited with the LR and
> see what I come up with. I'm pretty certain that in amongst the box
> of bits I got there's a spare regulator which was replaced but later
> found to be good. Give me a couple of days ...
>

Cheers again

--

Rich

Pas d'elle yeux Rhone que nous