Tracker Low Battery Warning

Even if no sun the batteries would still be more or less full if off load.............

Using words like "Intelligent" or "smart" in the context of  Sargent's EC500 or EC700 systems is open for debate. Yes these systems obviate the need I had in our 2003 Duetto when on EHU, to manually switch the battery charger between vehicle and leisure batteries depending on the voltages displayed on the meter.

In 2020 before any modifications in our Kemerton XL, when I measured the current drain of our EC700 with only the PSU on, it was 218ma. So 24/7 that's a current drain of 5 amps in 24hr. In winter and off EHU even with just an 80W solar panel that's barely enough to keep both batteries topped up.

Turn off the EC700 PSU and you've eliminated the 5 amp in 24 hrs drain but lost the use of monitoring the tracker provides, and for its insurance purposes too. Unless you modify the charging system you're always going to struggle maintaining battery voltages in the winter unless it is regularly connected to EHU. After all A-S aren't designing vans for their owners to camp off-grid for more than about 2 days.

Solutions
1. fit more solar and/or bigger solar panels, as I have said one solar panel for you and another to run your Sargent EC500 or EC700 system.
2. detach the basic solar controller that A-S fit on behalf of Sargent and fit a far more efficient separate dual battery MPPT type solar controller. I know of Votronic Duo Dig, Epever DuoRacer, possibly a Renology made duo controller.

I am unaware if Victron make a Duo battery solar controller. Using a Victron single battery controller then adding in a Batter Master box this alone will add an extra £70.
Road Pro UK sell the Votronic Duo Dig I fitted for £135, no need for a Battery Master.

Fitting a Battery Master would seem to be useful in older vans like our previous Duetto where I would have needed to keep switching the built-in battery charger. In the event I fitted a 69W solar panel and Sunsaver Duo PWM controller that was capable of charging both batteries simultaneously during day time.

Relaxez-Vous wrote:....

In 2020 before any modifications in our Kemerton XL, when I measured the current drain of our EC700 with only the PSU on, it was 218ma. So 24/7 that's a current drain of 5 amps in 24hr. In winter and off EHU even with just an 80W solar panel that's barely enough to keep both batteries topped up.

Turn off the EC700 PSU and you've eliminated the 5 amp in 24 hrs drain but lost the use of monitoring the tracker provides, and for its insurance purposes too. Unless you modify the charging system you're always going to struggle maintaining battery voltages in the winter unless it is regularly connected to EHU. After all A-S aren't designing vans for their owners to camp off-grid for more than about 2 days.
....

I haven't measured the EC700 drain for a while but I previously estimated it closer to 7Ah every 24 Hrs.  Whatever, that's more than a 80W solar panel can generate in a UK winter no matter what controller is fitted so it will lead to flat batteries if the EC700 is not shutdown.  

Sargent has explained to me that their communication tracker unit (EC 635/632) has two external 12v supplies.  One from the EC700 (which takes it power initially from the leisure battery and then the vehicle battery if the leisure battery goes flat or is disconnected) and other only from the leisure battery.  The supply from the EC700 powers the AS Monitor maintenance functions which cease to work when the EC700 is shutdown.  The 12v supply from the leisure battery however is unaffected by shutting down the EC700 and it continues to supply the tracker's security/theft functions which include three Thatcham alerts to the manned tracking centre in Bedford (leisure battery disconnected or inop, motorhome moved without ignition key and a triggered alarm which currently only works properly with Sargent's caravan alarm which can't be fitted to motorhomes.  Trust me - I have spent the last 3 years trying to get my alarm alert to work including a visit to Sargent.  The other security/theft function which continues to work with the EC700 shutdown is the tracking capability.  You can continue to access through AS Monitor under Locate a 6-hourly snapshot of where the motorhome was (which includes a snapshot of the leisure battery voltage and whether the tracker (it says alarm but means tracker!) was disarmed, armed or triggered) which the manned tracking centre can turn on remotely to real time continuous tracking if they need to.  If the leisure battery supply is cut the tracker's security/theft functions will be powered from the unit's internal battery which Sargent say can power it continuously for 3 years.  Shutting down the EC700 does not affect the motorhome's insurance.

I carried out the solar regulator mod to improve off-grid use in the summer.  Before carrying out the mod, I did not struggle maintaining winter battery voltages when the motorhome was out of use and not connected to an EHU.  All I did was shutdown the EC700 and let the solar panel keep the vehicle battery fully charged.  As I have said before, the leisure battery even though it was powering the tracker (no more than 10mA) would have been fine without charge for up to 3 months.

IanH wrote:Even if no sun the batteries would still be more or less full if off load.............

If I've understood correctly the OP hadn't started the engine for two weeks due to it being in storage, by which point it was down to 12.2v

It's a modern day vehicle, that amount of current draw sounds about right to me 

Probably is Roger, the ECU, and central locking etc can all have parasitic loads on the starter battery. White van man doesn't let his sit around for weeks on end so really only a problem on rarely used vehicles such as ours.
My, much older van has (measured) zero parasitic loads on the starter. My previous Warwick duo had, but our solar kept it full.
Either way 12.2 = discharged battery IMHO!

The OP hasn't reported a problem with his VB so I don't think the vehicle electrics load on the VB whist the motorhome has been out of use in storage is the issue.  We wait to hear from the OP again but my bet is that he didn't shutdown the EC700 whose significant load has discharged his LB.

Sorry for the delayed response, thanks for all your input, it looks like I'll be shutting down the EC700 when I put it back in storage and see how that works out.

MJF, I'll be interested to know how your battery voltages hold up with the EC700 turned off at the isolator, please keep us posted.

In early November after we had the waste water sensors playing up I was leaving our EC700 system on, I thought with 160W of solar panels the battery voltages here would be maintained, not quite. I suppose frequent trips to the van, using the central locking and electric step also won't have helped. The vehicle battery was heading towards 12.2V after dusk.

I've had the EC700 off for about a week but we've had such grey and rainy days recently that the solar hasn't been generating much power. This morning I also used a more expensive voltmeter (a UT61C) than the cheap one I bought some years ago in a French hypermarket. The cheaper meter under-reads by 0.05V. I'll measure again tonight with my Fluke and compare the reading from all 3 voltmeters. This morning it's foggy, the LB is >13.2V and VB>12.5V, the solar panels though were only delivering 0.5amps, now just 0.2amps. Without having the EC700 off at the isolator and stopping its 24/7 5 amps or more current drain, even having 160W I would struggle to keep the battery voltages maintained without EHU or taking the van out for a run. With modern vans you have to keep feeding the beast with power, if you don't you'll need to keep replacing clapped out batteries.

I've got the Votronic MPPT duo regulator.  We have a bit of brightness at the moment.  Our 80W panel is currently showing 19V, LB 13.45V and VB 12.9V.  The trickle charging regime for the VB is such that's its voltage is always about 0.5V below the LB charge.  This means the VB can't get as good a charge as the LB.  Typically in storage its charging voltage never exceeds about 12.9V (because the LB is fully charged) which I believe is sub-optimal (the PX300 float charge for either battery is 13.6V).  As I only fitted the regulator at the beginning of the year and since then have used the van every month it hasn't had a long out of use test with the EC700 shutdown but I have noticed after 4 weeks with intermittent use of the central locking the VB resting voltage was down to 12.6V when previously with all the solar charge going to the VB it maintained at least 12.7V with the Sargent regulator over a much longer winter period.

As it's now dark outside I took some more voltage readings.
The cheap multimeter appears to under-read by 0.07 volts compared with my UT61C and Fluke meters.
All meters report the LB 100% charged, as the voltages are equal to or are greater than 12.7 V.
The cheap meter indicated the LB 75% charged, my two others greater than 80% charged.

If I had the Western standard cell I remember from school I'd probably know if the cheap meter really was under-reading, anyway I'll know in future that some meters can be a bit inaccurate, consistently though.

Relaxez-Vous wrote:As it's now dark outside I took some more voltage readings.
The cheap multimeter appears to under-read by 0.07 volts compared with my UT61C and Fluke meters.
All meters report the LB 100% charged, as the voltages are equal to or are greater than 12.7 V.
The cheap meter indicated the LB 75% charged, my two others greater than 80% charged.

If I had the Western Standard cell I remember from school I'd probably know if the cheap meter really was under-reading, anyway I'll know in future that some meters can be a bit inaccurate, consistently though.

I've also seen small variations in voltage between meters and AS Monitor.  I have found the central locking load is enough to depress the VB voltage for a while.  I have also found that the voltage can remain elevated for several hours after the sun has gone down.  I've generally left the van unlocked for at least an hour before taking the measurement inside the van and late at night with a torch.  It's a shame historical snapshots of the VB voltage can't be seen on AS Monitor as they can for the LB voltage with the EC700 shutdown.