Voltage drops across the entire system

[ghost123uk]

well after fitting I have between 14 and 14.08 at the alternator and 13.55 at the starter battery

How long was it running for before you measured the battery Voltage ?

As I think it was Itchy pointed out, and I confirmed by tests, whilst the starter battery is recovering from starting the van, the Amps it pulls will drop the voltage at it's terminals (compared to at the alternator end). On mine (and I think Itchy's too) the voltage at the battery rose to almost the same as the output from the alternator after a couple of miles driving.

[jeffdub]

to be honest john it was sat on the drive ticking over, i'll try it again tomorrow after driving it for a couple of miles

[itchyfeet]

Also remember if your battery is in a poor state of charge because you don't use it enough then the batt may be pulling a considerable current for some time after starting.
Best to charge the battery with an intellegent charger first, for 24 hours or a non intellegent one for 12 hours to be sure that what you are seeing is not due to excessive charging current.

[jeffdub]

after driving for a couple of miles I now have 14.10 at the starter battery and 13.85 at the leisure battery

[MidLifeCrisis]

Well my poor man's Sterling arrangement has been fitted and operating for a few days now and I am very pleased with the results. At this point in time I have not had the opportunity to find out if my leisure battery is holding more Amp hours, but I reckon with the "smart charging" it will be.

Whoever it was who said that having the 2 batteries on separate charging circuits is better than having them linked in parallel via a relay, I agree

How's your charging system working out?
Have you had any opportunity to measure voltage/current being delivered to the leisure batt?

[ghost123uk]

Well my poor man's Sterling arrangement has been fitted and operating for a few days now and I am very pleased with the results. At this point in time I have not had the opportunity to find out if my leisure battery is holding more Amp hours, but I reckon with the "smart charging" it will be.

Whoever it was who said that having the 2 batteries on separate charging circuits is better than having them linked in parallel via a relay, I agree

How's your charging system working out?
Have you had any opportunity to measure voltage/current being delivered to the leisure batt?

Well I can say that the input voltage to the leisure from the "smart charger" is 14.4 Volts. After using the Propex (2 Amps) for around 4 hours (continuous = it was like a sauna in the van !!) the system fed 10 amps in for a while (time not recorded as I was driving at the time) after a 25 mile drive it had dropped to an input of 2 Amps which I understand is the final "trickle" charge, with the "smart charger" registering the battery on it's digital meter as 100% charged. The resting voltage at the starter battery remains at 12.9 as it always did.

Not really sure what all this proves, but as I said above, I am much happier having separate charging circuits for the 2 batteries, rather than heaving them in parallel. I am sure it is better for both batteries and will give me more "Amp Hours" usage from the leisure and likely longer overhaul service life from both.

I always wanted a "smart charger" and, as it is not hard wired in, it can easily be detached for more "normal" use.

E D I T = Font size html playing silly buggers !

[MidLifeCrisis]

Thanks for the update

Sounds like it's working pretty spot on then - if you can recover an 8 Amp-Hour loss in a 25 mile (let's say 45 min) drive then that would seem to be a winner!!!

Which smart charger are you using?
I guess it would be 'interesting' to know what the 'loss' was across the inverter/charger system but I guess it probably doesn't matter as long as the alternator isn't being 'taxed' too much?!?

Neat idea!!
(And I guess you can plug the charger direct into van 240v mains if you happen to be on hook-up)

[ghost123uk]

Which smart charger are you using?

A ring RSC512 (was reduced at a small branch of Motorworld last week to £34 ) - link to same here. I don't much like the shape, but it seems to work well.

I guess it would be 'interesting' to know what the 'loss' was across the inverter/charger system but I guess it probably doesn't matter as long as the alternator isn't being 'taxed' too much?!?

That was my thinking, as it is running off the alternator losses don't matter much. However, I believe these modern inverters are now pretty darn efficient anyway. At a guess, inverter and smart charger losses are likely to be only pulling a couple of amps more on average out of the back of the alternator than a standard split charge system. Plus I manually turn it off when I know I don't need it.

And I guess you can plug the charger direct into van 240v mains if you happen to be on hook-up

True

Neat idea!!

Thanks.

[lloydy]

I was sitting outside my kids school waiting for her to come out of club, when I remembered this thread.. So I thought I'd get my readings..
So,this is after a half hour drive with headlight, stereo and heater fan running (sterling charger charged batteries fully and now just maintaining). Reading taken with engine at idle with headlight stereo and heater fan running
Starter battery = 14.3v
Leisure battery (two in parallel) = 14.7v

[itchyfeet]

Is that diesel with batt in engine bay?
sounds odd that leisure is higher than starter
also wonder what brush pack/ regulator you have to generate 14.7V ( assuming voltmeter is accurate)?

[Mocki]

Itchy, lloydy has a Stirling , so it inverts the dc then transforms it back to a slightly higher voltage

[lloydy]

It is a diesel, but battery is now under rear seat. Mine is a tdi with a 120 amp alt. also, the leisures are controlled by the sterling charger which is some fancy fandango thing. Also all the high current cables are new and oversized.
After a rest (couple hours) starter is 12.8 and leisure is 12.7 (four interior lights were on when taking this measurement)
Multimeter is a good quality one, so should be pretty accurate....

[lloydy]

Itchy, lloydy has a Stirling , so it inverts the dc then transforms it back to a slightly higher voltage

this copy and paste describes it best i reckon

With the voltage amplifier they do the reverse. Sterling put a load on the alternator to pull the alternator voltage down. This fools the alternator into thinking that there is a major drain on the system and as such the standard regulator works at full current. However, the voltage is pulled down to a totally useless voltage for charging batteries. So the new system takes in this high current, but low voltage, and amplifies the voltage to charge the auxiliary battery bank at a much higher voltage than the base system voltage. In order to achieve the fast battery charging, the software control program and settings for this product are the same as for our Digital battery chargers and the Digital advanced alternator regulator.

[itchyfeet]

so does sterling connects to leisure and alt to starter?

[lloydy]

this link is how it works
http://sterling-power.com/collections/b ... y-chargers" onclick="window.open(this.href);return false;
also has a link on there for how its wired in. But basically the sterling connects to starter battery and leisure battery, and thats it. The bit i like is when you connect a 240v charger to the starter the sterling wakes up and charges the leisures