Battery management over Winter

[BigDean]

Morning all

I will not be using the Motorhome for 3+ months and would like advice on keeping the batteries topped up.

The system is intelligent and keeps both hab and leisure batteries charged. It is kept on my driveway and hookup is on a timer. What I currently do is have the EHU on for a few hours once a week which keeps them full.

The question is, is that a good schedule, or would I be better doing an hour or 2 per day, or a day each month? Or something else?

As always, comments appreciated.

Thanks
BigDean.

 

[Pausim]

Every time you turn the charger back on it will start the full charge cycle before eventually dropping back to a maintenance charge. I would be looking at providing a maintenance charge only or only turning the mains on when the batteries need it.

 

[Two on Tour]

If you say that it is an intelligent charging system you have, then just leave it on EHU as it will just take what it wants when it needs it to keep your batteries where the charging system see fit.

 

[ManTheVan]

Have you got any solar panel provision? If so, it’s likely to be able to supply the maintenance charge which Pausim mentioned above.

 

[BigDean]

If you say that it is an intelligent charging system you have, then just leave it on EHU as it will just take what it wants when it needs it to keep your batteries where the charging system see fit.

Thanks for that. Just looked in the manual and this is what it says:

OPERATION:
The battery charger uses a combination of constant current CC and constant voltage TC. This makes possible to significantly reduce charging time and prevents permanent damage to the battery.

The battery charger starts charging with CC current until the battery reaches a voltage value of Voc when it commutes to TC operation. At this stage the device provides constant voltage of Voc /Vf , the recharge current gradually decreases and the battery can be left permanently connected to the charger with no risk of damage.

So plugged in full time then!

Dont feel 100% comfortable doing that when I am not here, but it seems like that is the advice.

Thanks all.

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[BigDean]

Have you got any solar panel provision? If so, it’s likely to be able to supply the maintenance charge which Pausim mentioned above.

No solar.

Thanks

 

[BigDean]

Every time you turn the charger back on it will start the full charge cycle before eventually dropping back to a maintenance charge. I would be looking at providing a maintenance charge only or only turning the mains on when the batteries need it.

Looks like the manual, quoted above, says it knows these things....

Thanks

 

[Richard n Ann]

Leave a low power charger on continuously. The problem with switching power on every now and again is that it will add 1 charge cycle to the battery (albeit a small one)

I leave an optimate 2 on the leisure battery, it can only deliver 0.8 amps so there will never be a problem with battery overheating etc

 

[Odd-no-more]

Another vote for permanently on, it's what the modern chargers are designed for.

 

[Masman]

I leave mine on all the time when at home.Never had any problems with batteries.

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[Spriddler]

Thanks for that. Just looked in the manual and this is what it says:
--
.....the battery can be left permanently connected to the charger with no risk of damage.

So plugged in full time then!

Smart move, reading the manual - question answered in 18 minutes.

(We're blokes, innit).

 

[63720]

Imagine you were on a site with EHU for the winter, what would you do then?

 

[Off da Grid]

My solar does the same thing, hab battery is dated 2014 still going strong so can’t see it’s a problem leaving yours plugged in.

 

[Odd-no-more]

Smart move, reading the manual - question answered in 18 minutes.

(We're blokes, innit).

RTFM

 

[BigDean]

RTFM

Absolutely, but given I wouldn't know a VOC from a VF, in my experience, it is better to ask people that know, than guess!

If I can't program it from my laptop, then it is beyond my skills!

Thanks all for your input.

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[BigDean]

Imagine you were on a site with EHU for the winter, what would you do then?

That's actually an interesting point. If I hadn't asked this question, I would have been unsure. We don't always hook up as there is very little on 230v that we use, even when it is included in site fees.

 

[pappajohn]

We don't always hook up as there is very little on 230v that we use, even when it is included in site fees.

I would if included..... Chance to charge batteries, run fridge on 230v and hot water if that has 230v option.
Why not, your paying for it

 

[autorouter]

So plugged in full time then!

Dont feel 100% comfortable doing that when I am not here, but it seems like that is the advice.

You can check the voltage in maintenance mode when it's reached the 'float voltage' Vf. It should be about 13.4 to 13.8V. The float voltage is exactly the voltage where there is no charge going in or out of the battery. Actually it puts a few milliamps in, to just compensate for the internal self-discharge of the battery. Keeps it topped up and stops it going flat over a period of weeks.

 

[thebriars]

Provided there is no current draw on the hab battery, I know from caravanning days that it was only necessary to put a battery on charge once every couple of months, and even then the charge needed was less than10ah. - I have a charger that tells you the charge it puts into a battery. Very useful!

 

[Off da Grid]

If the ehu is included I plug in just for the fridge and the kettle in the summer as the solar takes care of the rest

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[BigDean]

Thank you everyone who has contributed. Will be leaving plugged in!

So following up on that, as its plugged in, should I set the timer on the heating to come on at any point to keep the van "aired"

Thanks
Dean

 

[Pausim]

Keeping an even temperature is important in avoiding condensation. If your heating comes on occasionally the warm air can absorb more water and as it cools again there is a risk of condensation and damp. Short periods of heating only warm the air, not the structure, which means that when the heating goes off there are plenty of cold surfaces for moisture to condense on. I would just open the doors and windows on a dry sunny day from time to time.

 

[BigDean]

Keeping an even temperature is important in avoiding condensation. If your heating comes on occasionally the warm air can absorb more water and as it cools again there is a risk of condensation and damp. Short periods of heating only warm the air, not the structure, which means that when the heating goes off there are plenty of cold surfaces for moisture to condense on. I would just open the doors and windows on a dry sunny day from time to time.

Thanks for that Pausim, the problem is that we wont be here...... So presume best just to leave it and deal with the consequences on my return next year.

Thanks
BigDean

 

[Pausim]

Thanks for that Pausim, the problem is that we wont be here...... So presume best just to leave it and deal with the consequences on my return next year.

Thanks
BigDean

My motorhome lives in a compound without electricity and I have no heating on in the winter. I leave the blinds closed which keeps the sun off the furnishings and reduces the heating effect of sunlight. It works for me.

 

[Off da Grid]

I took a punt on one of those cheap shoebox size dehumidifiers, rewired the low voltage plug so I could use it with my 12v power converter to 9v so the Votronic mppt aes out switch avia a relay switches it on when the batteries are full.
Works a treat to keep the condensation down, and doesn’t cost me a penny to run.

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[denisejoe]

I took a punt on one of those cheap shoebox size dehumidifiers, rewired the low voltage plug so I could use it with my 12v power converter to 9v so the Votronic mppt aes out switch avia a relay switches it on when the batteries are full.
Works a treat to keep the condensation down, and doesn’t cost me a penny to run.

It’s a box on wheels that is not completely sealed so any moisture you remove will be replaced. If it was a good idea dealers would be doing it.