Batteries failing maybe?

[TrevandJenny]

We have a 2017 Autosleeper Broadway with a Sargent EC328 electrician system. I removed the original 100amp lead acid battery in 2019 and replaced it with 2 x 100amp AGMs. Last year I removed the original 80watt Solar panel and replaced it with a 120 watt, the highest I could with the EC328.
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The Sargent panel only shows voltage at the time the switch is pressed, either leisure or vehicle. As such I fitted a switched digital voltage reader direct from the leisure batteries.This shows a voltage normally .3 to .4v higher than the control panel as expected. The panel does not show any other electricial readings other than battery voltage.
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As such I cannot see read any other values, Here the problem
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We have been away for three weeks and I have noted a decline in voltage readings, Last night was our first on hook up for the last 6 days as being on THS sites As it’s been overcast in that time I realised poor solar harvesting was maybe the problem, In that time we had driven for an hour after a four night stopover, then the same after a two night stopover, We have now been on hook up for 16 hours and voltage still in the 13v range.
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Main question is How do I tell the condition of the AGM leisure batteries?

 

[wildebus]

It is normal, as you have seen, to see the sargent control panel showing a voltage reading significantly lower than the actual battery voltage.
I have the Sargent 325 - your 328 is virtually identical (if a 325 goes to Sargent for repair, I believe they come back out as a 328 in fact) - and I think I recall that you can actually get an Amperage reading on the control panel? It is not something I have or would use TBH so can't recall the precise details but I think it is possible and I think from memory it is actually fairly accurate?

Back to the main question - how can you tell the conditon of the battery? The best way is a load test. You need some way to measure the draw on the battery to do this.
1) If you had a battery monitor that would tell you.
2) If you don't, then find a load around a 1/20th of the battery capacity (in your case, it would be 10A) and run that load continuously for 10 hours from a fully charged state and with no charging (turn off solar, pull EHU), then disconnect the load, and see what the battery voltage is around an hour later. It should be 12.05V or thereabouts.

The Sargent systems are not that great at battery charging to be frank, and your batteries may never be getting fully charged to start with, and over time, they may have lost their top end capacity due to that.

In terms of expectations, quite a few people think when the voltage starts to drop after removing the charger, the battery is losing charge? It is just settling and a fully charged OFF-CHARGER Lead Acid battery will be at around 12.7-12.8V (depends a little on battery type). If you are seeing that happen, perfectly normal.
The key thing with Lead Acid is how quickly the voltage drops - your 200Ah Bank *should* be down to approx 12.05V after 100Ah has been taken out. 100Ah is a fair amount when camping in the 'regular' way. If you have hairdryers, toasters, microwave, etc, it can happen much faster. Crux of the matter is without a way to measure the load over time, it is very hard to know if there is a problem. (And you might have a residual draw you are not aware of as well which is sucking the battery power).

 

[Mr and Mrs Tupcox]

Having had vans that use the factory fitted wires that go to the leisure batts. Through the Sargent system.
I was advised by one of our technical guys on wc.
To fit new battery cables, direct from solar charger to leisure batts, avoiding the Sargent system.
This let me have more solar on roof.
And was a great improvement.
And driving for an hour in my experience will not fully charge batts.

Sure one of our very experienced technical guys will reply ..

 

[marchie]

We have a 2017 Autosleeper Broadway with a Sargent EC328 electrician system. I removed the original 100amp lead acid battery in 2019 and replaced it with 2 x 100amp AGMs. Last year I removed the original 80watt Solar panel and replaced it with a 120 watt, the highest I could with the EC328.
.
The Sargent panel only shows voltage at the time the switch is pressed, either leisure or vehicle. As such I fitted a switched digital voltage reader direct from the leisure batteries.This shows a voltage normally .3 to .4v higher than the control panel as expected. The panel does not show any other electricial readings other than battery voltage.
.
As such I cannot see read any other values, Here the problem
.
We have been away for three weeks and I have noted a decline in voltage readings, Last night was our first on hook up for the last 6 days as being on THS sites As it’s been overcast in that time I realised poor solar harvesting was maybe the problem, In that time we had driven for an hour after a four night stopover, then the same after a two night stopover, We have now been on hook up for 16 hours and voltage still in the 13v range.
.
Main question is How do I tell the condition of the AGM leisure batteries?

We had an Ablemail AMT12 Battery Charger/Maintainer fitted by David of Wildebus to force the Leisure Battery to top up the Vehicle Battery, enabling the former to harvest more Solar. We are scheduled to have 2 x Ablemail ABB07 fitted [by David] that will use the Ablemail App to show state of charge of both batteries to save the 'open bonnet, flick open plastic catch on liver Vehicle Battery terminal and then use a multimeter to see how the latter is performing

My knowledge is lower than your battery voltage, but I'm sure I read a couple of posts indicating that your level of driving may not be enough to recharge the Leisure Battery fully after 6 days usage. I think it also depends on what work the Leisure Battery has had to do whilst parked up, but David will be able to give more technical advice than I shall ever know, so over to him!

Steve

 

[wildebus]

Having had vans that use the factory fitted wires that go to the leisure batts. Through the Sargent system.
I was advised by one of our technical guys on wc.
To fit new battery cables, direct from solar charger to leisure batts, avoiding the Sargent system.
This let me have more solar on roof.
And was a great improvement.
And driving for an hour in my experience will not fully charge batts.

Sure one of our very experienced technical guys will reply ..

I actually like the Sargent System (the EC325) that is fitted in my Autotrail and think it is a very neat PDU - Power Distribution Unit.
However, as a Battery CHARGING unit, it is very basic and for anyone who wants to get the best out of their batteries, it is (IMO) rubbish. For a Caravan or Campsite user who only needs batteries to see them from one site to another, it is adequate, but for anyone who wants to spend time off-grid .... nah.
One of the first things I did with my Motorhome when I got it was to get a Victron EasyPlus 12/1600/70 - EHU Charging; Ablemail AMC12-12-60 - B2B Charging; and Victron MPPT 100/20 - Solar Charging, and bypass all the charging features from the Sargent.