Taking care of my vehicle battery

[andy63]

You really need to find out what the drain on the start battery is..in spite of your reluctance ..
It may be reasonable but if there is an excess drain there's not much sense in trying to find a solution to mask a problem..imo.
The other point that comes to mind..ifthe drain isn't excessive then if you want to fit a device that will charge the start battery at the expense of the leisure battery then a van bitz battery master is what is required..it doesn't work on a voltage threshold but instead a differential..so it will drain down the leisure more to keep the start topped up..
As long as you are confident that your solar can keep the leisure right that would be better than running inverters ..again just my opinion..
Andy..

 

[chenderson1965]

I

You really need to find out what the drain on the start battery is..in spite of your reluctance ..
It may be reasonable but if there is an excess drain there's not much sense in trying to find a solution to mask a problem..imo.
The other point that comes to mind..ifthe drain isn't excessive then if you want to fit a device that will charge the start battery at the expense of the leisure battery then a van bitz battery master is what is required..it doesn't work on a voltage threshold but instead a differential..so it will drain down the leisure more to keep the start topped up..
As long as you are confident that your solar can keep the leisure right that would be better than running inverters ..again just my opinion..
Andy..

I already have a Battery Master (see above). I don’t think it’s drain. I think the BM feeds through 1A if the differential is high enough. At this time of year we have a maximum of 8h sunlight so I doubt the threshold is being exceeded for much more than this. If the BM is able to get the battery close to full charge (12.7v), it’s only taking perhaps 8-10Ah max. That can’t be right - which sugggests it’s a battery issue rather than a drain/leakage issue.

 

[andy63]

I


I already have a Battery Master (see above). I don’t think it’s drain. I think the BM feeds through 1A if the differential is high enough. At this time of year we have a maximum of 8h sunlight so I doubt the threshold is being exceeded for much more than this. If the BM is able to get the battery close to full charge (12.7v), it’s only taking perhaps 8-10Ah max. That can’t be right - which sugggests it’s a battery issue rather than a drain/leakage issue.

Sorry..must have picked it up incorrectly..I thought you said your leisure remained satisfactory but your start dropped to 12v.. I would have thought there would have been sufficient differential for the battery master to maintain a charge at those voltages..
You also made reference to the leisure getting to a level to divert a charge which made me think your device worked on a threshold voltage..
Andy

 

[68c]

Is it a genuine Battery Master or a copy. I took my chinese version apart, just contained a resettable fuse, resistor and diode. Looks like the resettable just protects from high current inrush, the diode means current only flows from leisure to starter batt and the resistor , with the diode, providing the voltage difference. With this chinese version current will always flow from the leisure batt to the starter batt PROVIDING the leisure batt is at a higher voltage than the starter batt. There is nothing there to stop both batteries slowly depleting until the starter batt is flat and the leisure batt holds a few volts. I assume the dearer and much revered Vanbitz version is a little more clever.

 

[chenderson1965]

Is it a genuine Battery Master or a copy. I took my chinese version apart, just contained a resettable fuse, resistor and diode. Looks like the resettable just protects from high current inrush, the diode means current only flows from leisure to starter batt and the resistor , with the diode, providing the voltage difference. With this chinese version current will always flow from the leisure batt to the starter batt PROVIDING the leisure batt is at a higher voltage than the starter batt. There is nothing there to stop both batteries slowly depleting until the starter batt is flat and the leisure batt holds a few volts. I assume the dearer and much revered Vanbitz version is a little more clever.

It’s a VanBitz one.

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[Cass18]

Our van is in storage ( outdoors) we have solar panels and currently sat outside it with engine on to turn it over intend to take it out later this week for a run out. No idea what these figures mean on the panel anyone tell me if this is good or bad ?

 

[Ledzep]

Trickle charger is definitely the answer we use this charger.

Amazon product ASIN B00DW6RHN2​

We use one of these and it's brilliant keeps both Hab and Engine battery fully charged.

Surely this is the same as leaving the EHU connected?

 

[Cheshirecat57]

You may well be right, but before I start shelling out cash, I’m hoping someone can give me some authoritative information.

Even if I replace the battery, I still need to know the answer to my original question so I don’t damage the new one.

My opinion
if you battery drops to 12.0 v overnight after a days charging, its buggered

Mine is in storage and shows 13.0 to 13.1 in the day ( solar working) and at daybreak it is at 12.7

 

[Ledzep]

My opinion
if you battery drops to 12.0 v overnight after a days charging, its buggered

Mine is in storage and shows 13.0 to 13.1 in the day ( solar working) and at daybreak it is at 12.7

Are there any downsides to leaving a MH permanently EHU 'd to keep batteries charged I wonder? Answers please-thanks

 

[two]

Are there any downsides to leaving a MH permanently EHU 'd to keep batteries charged I wonder? Answers please-thanks

It depends on the charger and batteries.
New 'intelligent' chargers are probably OK, dropping down to a small float charge.

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[robnchris]

Surely this is the same as leaving the EHU connected?

Not at all this charger provides only a trickle charge.

 

[two]

Not all chargers are the same, some are better than others.
It will depend on what kind of charger you have installed with your EHU and if it is able to respect the installed battery chemistry (Wet/Gel/AGM/Lithium) correctly.
I prefer to run mine about once a month for a day (or two) rather than continuously.
I'm sure there are some who leave theirs on EHU without apparent harm, however.
The difficulty is that, until they fail to hold any charge at all, you cannot tell how much batteries have deteriorated without doing a prolonged discharge test and I suspect that few ever bother with that. Furthermore, you cannot tell what might have happened if you treat it otherwise. I have lost many batteries in the past by 'frying' them, having kept them on a primitive charge continuously, or by leaving them to discharge completely. Modern chargers take better care than the earlier ones but not all manufacturers install the best due to their cost.

 

[autorouter]

No idea what these figures mean on the panel anyone tell me if this is good or bad ?

I'm not familiar with this solar controller, but at a guess, 70:30 is the percentage split between the leisure battery and the starter battery. There will probably be a menu somewhere to change this if required. 90:10 is quite a popular setting.

20.3V is the solar panel voltage. I think 13.6A is the solar panel current (amps). That's the input into the solar controller. If it is the solar panel current then the panels are generating 20.3 x 13.6 = 272W, so you must have a lot of panel up there.

The output voltage to the batteries will be about 13V to 14.5V, and certainly not 20.3V. You'll have to press the appropriate buttons to show that.

The 896Ah looks like the total charge from the solar panels since the measurement started. There's at least a week's worth there, or much longer if during the winter months.

I don't know what the 0.0A means. If it's the amps going to one of the batteries, maybe there is a problem there. Bad connection or fuse. The amps are unlikely to be zero, unless one battery is completely full. Or maybe it's one of those controllers that doesn't charge Battery 2 until Battery 1 is at least 70%.

Maybe it would have been better to start a new thread rather than stick it in the middle of this one, but I suppose it's quite related to the subject.