I have a 24v system comprising:

4x12v 135amp Domestic batteries.

They are connected as 2 pairs of batteries wired in parallel to give a 2 x
24v and then the 2 pairs are connected in series.

2x12v engine starter batteries connected in series

My question. when I connect these to the boat, should I take the positive
and negatives feeds from the same battery/ battery pair or one from each?
Does it matter?'

Nigel wrote:
I have a 24v system comprising:

4x12v 135amp Domestic batteries.

They are connected as 2 pairs of batteries wired in parallel to give a 2 x
24v and then the 2 pairs are connected in series.

2x12v engine starter batteries connected in series

My question. when I connect these to the boat, should I take the positive
and negatives feeds from the same battery/ battery pair or one from each?
Does it matter?'





It may not matter much, Nigel, but the preferred way of doing it is to
run one feed to each series pair, rather than both to the same series pair.

That is intended to ensure both series pairs "see" the same load and
receive the same charging voltage.

Make sense?

Chuck

Hi Nigel,

When you have batteries arranged this way you need to be very careful
that they charge and discharge in balance. Otherwise you end up with
voltage variations between the pairs that leads to early failure (I
know - it seems odd). Your positive lead should connect first to one
pair and the negative first to the other pair.

Here's a diagram of correct wiring from the high end german battery
supplier - Sonnenschein.

http://www.sonnenschein.org/Really%20FAQ's.htm

Carl

Carl wrote:
Hi Nigel,

When you have batteries arranged this way you need to be very careful
that they charge and discharge in balance. Otherwise you end up with
voltage variations between the pairs that leads to early failure (I
know - it seems odd). Your positive lead should connect first to one
pair and the negative first to the other pair.

Here's a diagram of correct wiring from the high end german battery
supplier - Sonnenschein.

http://www.sonnenschein.org/Really%20FAQ's.htm

Carl

That is a common but unfounded myth.

With appropriate jumpers between the parallel batteries, the voltage
difference caused by cables entering/exiting from the same side are
less than 0.001 volts which is far less than internal battery
incongruities and will have zero effect on the battery life.

If the two batteries were separated by a considerable distance, say 10
feet, and the jumpers between them were smaller than the starter motor
cables, in that case one battery would tend to be used slightly more
than the other but only during heavy loads. As soon as the load is
removed, the batteries will equalize within a few seconds.

Andina Marie

On 2 May 2006 06:21:06 -0700, "Andina Marie" wrote:


Carl wrote:
Hi Nigel,

When you have batteries arranged this way you need to be very careful
that they charge and discharge in balance. Otherwise you end up with
voltage variations between the pairs that leads to early failure (I
know - it seems odd). Your positive lead should connect first to one
pair and the negative first to the other pair.

Here's a diagram of correct wiring from the high end german battery
supplier - Sonnenschein.

http://www.sonnenschein.org/Really%20FAQ's.htm

Carl

That is a common but unfounded myth.

With appropriate jumpers between the parallel batteries, the voltage
difference caused by cables entering/exiting from the same side are
less than 0.001 volts which is far less than internal battery
incongruities and will have zero effect on the battery life.

If the two batteries were separated by a considerable distance, say 10
feet, and the jumpers between them were smaller than the starter motor
cables, in that case one battery would tend to be used slightly more
than the other but only during heavy loads. As soon as the load is
removed, the batteries will equalize within a few seconds.

Andina Marie
I completely and utterly disagree!!!!!

Richard

Nb "Pound Eater" Parkend G+S