Battery And Charging Advice Appreciated

[KR.]

My electrical system for the van is composed of an Xtreme 110ah leisure battery (XR1750Dc), Sargent EC155 PSU and Ablemail 12-12-30 charger. I'd hoped that regular weekly runs up north and return of 3-500 miles would keep the battery charged but realise I've been too optimistic and the battery while showing nigh on 100% on arrival after a drive of several hours literally ticks back down to 80% in minutes, using lights only, where it seems to settle before dropping at a more agreeable rate. I don't use hookup or mains charging, the battery is less than a year old.

Questions :
1. Am I right in thinking that lack of mains charging has caused my battery to deteriorate to it's reduced capacity ?
2. Do I need a mains charger to sit between the house mains and the battery, and use it on a weekly basis ?
3. What is the Ablemail charger actually doing ?
4. Can the EC155 power up the battery to 100% via mains ?

I'm thinking of the coming winter and I'd be willing to pay (again!) for a new battery if I could be sure of having near 100% capacity available to power my HS2000 heater and LED lighting for overnighting at somewhere cold like a ski centre car park in the Highlands, that's not a huge power draw but I've no confidence that my battery will provide that given the cold temperature and the 50% discharge limit. If it's 10 degrees in the van on arrival am I right in thinking the battery is about 20% down to start with so I'm looking at something like a useable 30ah or so out of a fully charged 110ah battery?

To complicate matters, the reason I barely use the mains for charging is the hassle of running the cable from
the back of the house to the drive, the battery itself is low profile and sits under the drivers seat so there isn't much room for regular attaching and detaching charging leads to the battery, a more permanent fix would be required.

Any tips, suggestions welcome and feel free to put any misconceptions straight, I've never quite got my head around the setup.

 

[mmi]

From where you got the percentage (100%, 80%) readings you mentioned?

 

[t0mb0]

From where you got the percentage (100%, 80%) readings you mentioned?

This is the critical question...

 

[Dieseldonkey]

I have the same battery and Ablemail 12 12 30 DC DC charger @KR. The Ablemail starts charging your leisure battery when your engine starts up. However even when the engine is turned off, the Ablemail continues to harvest power from the vehicle battery, until the vehicle battery drops to a preset voltage. But when not being charged, my battery drops over a period of time to about 12.8 volts. (Measured voltage close to but not quite at the battery terminals.) The graph below shows what the Ablemail is doing. Engine on at 0100hrs. Ablemail shuts off about 0200hrs. Voltage drops and settles about 12.8 volts from there. Ignore from 0800hrs onwards. This is sun up and the solar panel kicking in with charging the battery.

 

[KR.]

From where you got the percentage (100%, 80%) readings you mentioned?

I'm doubled up on battery monitors, the EC155 is accompanied by the EC50 control panel.
EC50 Control Panel | Shop | Sargent Electrical

and I've got a NASA BM Compact Monitor
BM-1 Compact - Nasa Marine Instruments


The EC50 has a series of lights that gives you a range of charge, the monitor provides a voltage and actual %, both monitors supply similar readouts.

 

[KR.]

I have the same battery and Ablemail 12 12 30 DC DC charger @KR. The Ablemail starts charging your leisure battery when your engine starts up. However even when the engine is turned off, the Ablemail continues to harvest power from the vehicle battery, until the vehicle battery drops to a preset voltage. But when not being charged, my battery drops over a period of time to about 12.8 volts. (Measured voltage close to but not quite at the battery terminals.) The graph below shows what the Ablemail is doing. Engine on at 0100hrs. Ablemail shuts off about 0200hrs. Voltage drops and settles about 12.8 volts from there. Ignore from 0800hrs onwards. This is sun up and the solar panel kicking in with charging the battery.

So in effect what it's doing is providing some charge for a period beyond engine off, unlike the alternator which will only provide while engine on/vehicle moving?
I was going to mention solar panels but didn't want to complicate things, I'll try and get what I've got working properly first!

 

[Dieseldonkey]

@KR. Also, did you check to see where your battery voltage returns to when you turn the lights off. Here's a graph showing my fridge running through the night. Note the voltage drop each time it kicks in at 0030, 0300, 0630hrs, but how it steps back up again when it turns off. Theres considerable voltage drop when I turn on the kettle for a coffee at 0800hrs, but it recovers albeit the solar is starting up.

 

[t0mb0]

I have the same battery and Ablemail 12 12 30 DC DC charger @KR. The Ablemail starts charging your leisure battery when your engine starts up. However even when the engine is turned off, the Ablemail continues to harvest power from the vehicle battery, until the vehicle battery drops to a preset voltage. But when not being charged, my battery drops over a period of time to about 12.8 volts. (Measured voltage close to but not quite at the battery terminals.) The graph below shows what the Ablemail is doing. Engine on at 0100hrs. Ablemail shuts off about 0200hrs. Voltage drops and settles about 12.8 volts from there. Ignore from 0800hrs onwards. This is sun up and the solar panel kicking in with charging the battery.

View attachment 50115

Doesn't the Ablemail have an ignition input? Assuming it does, it really shouldn't be drawing current from the starter when the ignition is off should it? How are you telling whether it's still charging - isn't the ignition going off just after 0200hrs in the picture? The long tail of voltage coming down after charging is completely expected, it's the memory effect in the battery.

 

[t0mb0]

I'm doubled up on battery monitors, the EC155 is accompanied by the EC50 control panel.
EC50 Control Panel | Shop | Sargent Electrical

and I've got a NASA BM Compact Monitor
BM-1 Compact - Nasa Marine Instruments


The EC50 has a series of lights that gives you a range of charge, the monitor provides a voltage and actual %, both monitors supply similar readouts.

The NASA is integrating up current flow, so if that thinks it's dropping from 100% to 80% in a matter of minutes, I can think of only two root causes:

1) The NASA is mis-calibrated somehow, not correctly setting the 100% level which is then causing odd behaviour when a bit of current draw happens.
2) You have some very large load genuinely draining the battery quickly.

You should be able to tell by keeping an eye on the actual current flow over the period when it's claiming to drop from 100% to 80%. The current will be very large if it happens over 10 minutes or so. If there isn't some huge current over the period, then the NASA is mis-calibrating the 100% level somehow.

 

[Dieseldonkey]

So in effect what it's doing is providing some charge for a period beyond engine off, unlike the alternator which will only provide while engine on/vehicle moving?
I was going to mention solar panels but didn't want to complicate things, I'll try and get what I've got working properly first!

That's my understanding of it, yes. I believe the Ablemail can be configured differently if required but if your LED indicator keeps flashing green when your engines been turned off, then it's still charging the leisure battery from the vehicle battery.

 

[Dieseldonkey]

Doesn't the Ablemail have an ignition input? Assuming it does, it really shouldn't be drawing current from the starter when the ignition is off should it? How are you telling whether it's still charging - isn't the ignition going off just after 0200hrs in the picture? The long tail of voltage coming down after charging is completely expected, it's the memory effect in the battery.

The Ablemail has a 'sense' wire. It connects straight to the vehicle battery positive post, as opposed to an 'ignition on' feed. Protected by a one amp fuse. Pulling the fuse prevents it from harvesting from the vehicle battery.

 

[t0mb0]

The Ablemail has a 'sense' wire. It connects straight to the vehicle battery positive post, as opposed to an 'ignition on' feed. Protected by a one amp fuse. Pulling the fuse prevents it from harvesting from the vehicle battery.

View attachment 50118

Urgh, that’s less than ideal. I wonder whether it can be configured to take its ‘sense’ wire from an ignition feed.

 

[KR.]

@KR. Also, did you check to see where your battery voltage returns to when you turn the lights off. Here's a graph showing my fridge running through the night. Note the voltage drop each time it kicks in at 0030, 0300, 0630hrs, but how it steps back up again when it turns off. Theres considerable voltage drop when I turn on the kettle for a coffee at 0800hrs, but it recovers albeit the solar is starting up.

I've just nipped out to the van and the readings on the BM monitor were :

Switch on, lights on
75% (capacity) / 12.4v / 1.3a

within 2 minutes
65% / 12.3v / 1.3a
(Time to discharge 55 hours).

switch lights off and within 3 minutes
75% / 12.4v / 0.1a
(Time to discharge 199h)

That final 0.1a will be from the small current taken by the monitor itself, it switches itself off after a minute or two. As I've said it's quite disconcerting turning up at an overnight spot off grid, switching the lights on and seeing my capacity dropping from 85% to 75% in minutes, it doesn't give me any confidence. I'm also of the understanding that these percentages are more of a
guideline but when it says I've 80% juice left, I've only got 30% as I shouldn't be dropping the battery below 50%?

 

[Dieseldonkey]

Urgh, that’s less than ideal. I wonder whether it can be configured to take its ‘sense’ wire from an ignition feed.

I suppose if the 'sense' wire was attached to an ignition on feed, then when the ignition was off, the voltage in the sense wire would be 0v. The same as breaking the circuit or pulling the fuse. So turning off the ignition should prevent any post engine off charging.

 

[KR.]

That's my understanding of it, yes. I believe the Ablemail can be configured differently if required but if your LED indicator keeps flashing green when your engines been turned off, then it's still charging the leisure battery from the vehicle battery.

I've noticed the green light when parking up so it is working as you say.

 

[KR.]

The NASA is integrating up current flow, so if that thinks it's dropping from 100% to 80% in a matter of minutes, I can think of only two root causes:

1) The NASA is mis-calibrated somehow, not correctly setting the 100% level which is then causing odd behaviour when a bit of current draw happens.
2) You have some very large load genuinely draining the battery quickly.

You should be able to tell by keeping an eye on the actual current flow over the period when it's claiming to drop from 100% to 80%. The current will be very large if it happens over 10 minutes or so. If there isn't some huge current over the period, then the NASA is mis-calibrating the 100% level somehow.

I'm certain that there isn't some big load draining the battery, the monitor does show the current draw - 1.4A for lighting for example, and I can see the drop happening. I would like to think the NASA is mis calibrating but the figures are backed up by the EC50 control panel light indications. That kind of leaves the actual battery I suppose - you mention 'memory effect' upthread, is it possible that my battery best state is now 80% and while it may momentarily show 100% after charging it returns to that 80% as the best it can now manage?

 

[t0mb0]

I'm certain that there isn't some big load draining the battery, the monitor does show the current draw - 1.4A for lighting for example, and I can see the drop happening. I would like to think the NASA is mis calibrating but the figures are backed up by the EC50 control panel light indications. That kind of leaves the actual battery I suppose - you mention 'memory effect' upthread, is it possible that my battery best state is now 80% and while it may momentarily show 100% after charging it returns to that 80% as the best it can now manage?

The panel is probably just using a simple voltage proxy for state of charge and so is probably getting confused by the memory effect on voltage. What the actual true Ah of the battery is, after a years worth of wear and tear is almost impossible to determine. The critical thing with a current integrating device like the NASA is that it correctly detects when the battery is full (by detecting high charging voltage and close to zero current flow in) to determine the battery is full. If it never detects a full state properly, the errors in integrating up current accumulate over time until it's wildly unreliable.

 

[t0mb0]

I've just nipped out to the van and the readings on the BM monitor were :

Switch on, lights on
75% (capacity) / 12.4v / 1.3a

within 2 minutes
65% / 12.3v / 1.3a
(Time to discharge 55 hours).

switch lights off and within 3 minutes
75% / 12.4v / 0.1a
(Time to discharge 199h)

That final 0.1a will be from the small current taken by the monitor itself, it switches itself off after a minute or two. As I've said it's quite disconcerting turning up at an overnight spot off grid, switching the lights on and seeing my capacity dropping from 85% to 75% in minutes, it doesn't give me any confidence. I'm also of the understanding that these percentages are more of a
guideline but when it says I've 80% juice left, I've only got 30% as I shouldn't be dropping the battery below 50%?

But this shows it's actually going up, from 65% to 75%?? If you don't have any current going in over this time, the NASA is definitely whacko...

 

[Dieseldonkey]

Urgh, that’s less than ideal. I wonder whether it can be configured to take its ‘sense’ wire from an ignition feed.

There's a guide PDF file within this link, with an explanation as to why the Ablemail functions in this way @t0mb0 . Interesting info, if it's your kind of thing.

EURO 5 and EURO 6 battery charger selection and smart alternator operation explanation | 0161 745 7697

 

[KR.]

But this shows it's actually going up, from 65% to 75%?? If you don't have any current going in over this time, the NASA is definitely whacko...

Okay, so the best thing to do would be to fully charge my battery, reset the NASA and see how it behaves. How do I fully charge my battery, and how do I check it? Can I do this through the hookup and EC155 PSU (I have a vague recollection that the EC155 isn't much cop at fully charging the battery?), or would I need a standalone charger connected to the mains. If so, could I hookup on my drive then connect a charger to the 240v socket inside the van and then charge the battery?
I've also got the problem that I'm going to have to lift my seat to get access to the battery terminals, so I need to do something here, perhaps rig something up that allows me to access the battery through the panel on the rear of the seat base.