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Best Battery and Charger for Standby Battery

Posted: 10 Jan 2016, 09:45
by Paule39
I leave my van parked up for long periods in the winter due to working away from home. Result is the starter battery often discharges in a week or two, especially with the cold weather.

I have decided to buy a spare starter battery and keep it charged up indoors and swap it over every couple of weeks. I'm looking at the following:

Varta D21 battery (or should I go for a higher spec?):
https://www.tayna.co.uk/D21-075-Varta-S ... P7743.html" onclick="window.open(this.href);return false;

and either use my existing cheap trickle charger:
http://www.argos.co.uk/static/Product/p ... 405392.htm" onclick="window.open(this.href);return false;

or wondering if I should get a battery conditioner (as I might be leaving the battery charging up for a longer period over the summer):
http://www.halfords.com/motoring/bulbs- ... ry-charger" onclick="window.open(this.href);return false;

1989 1.9 petrol T25 Westfalia Vanagon

Re: Best Battery and Charger for Standby Battery

Posted: 10 Jan 2016, 11:44
by BOXY
Just buy a couple a batteries from a local scrap yard. If they're only being used to keep the alarm etc ticking over it will be the cheapest option. If the van has got hook-up can you use that to charge the batteries in-situ.

Re: Best Battery and Charger for Standby Battery

Posted: 10 Jan 2016, 12:12
by Paule39
BOXY wrote:Just buy a couple a batteries from a local scrap yard. If they're only being used to keep the alarm etc ticking over it will be the cheapest option. If the van has got hook-up can you use that to charge the batteries in-situ.

Thanks, I have a hook up and a sterling charger fitted and can charge the batteries that way but I cant always park up outside my house, hence the need for this option. Also, the battery doesn't always drain if I only leave it for a week or two (depends on the weather).

Its become a such a pain in the neck when the battery drains and Ive been away that I'm not too worried about (reasonable) :D cost, I'm fed up with taking the battery out and charging it up when drained and having to wait 2 days before I can take then van out again. Ideally I want the option to be able to take the drained battery out, put the charged one in and drive off in one go. I can then put the other battery on charge when back from a run.

Re: Best Battery and Charger for Standby Battery

Posted: 10 Jan 2016, 12:37
by CJH
Short of tracing the parasitic drain to find out why your battery is going flat, why not just disconnect it while it's parked up? The drain is probably your radio's memory setting, but presumably it loses it's presets when you swap the battery anyway, so you'll be no worse off in that respect.

Maybe consider putting a battery isolator in, so that you have an added level of security.

Re: Best Battery and Charger for Standby Battery

Posted: 10 Jan 2016, 12:54
by Paule39
CJH wrote:Short of tracing the parasitic drain to find out why your battery is going flat, why not just disconnect it while it's parked up? The drain is probably your radio's memory setting, but presumably it loses it's presets when you swap the battery anyway, so you'll be no worse off in that respect.

Maybe consider putting a battery isolator in, so that you have an added level of security.

Thanks - I considered that, but want to keep the alarm going (it may well be the radio/alarm draining as you say). I have kept it parked up in the summer for a few weeks and it didn't drain, so I suspect its the weather :?: :?: :?

Re: Best Battery and Charger for Standby Battery

Posted: 10 Jan 2016, 13:01
by ghost123uk
Or just keep a half decent, well charged battery at home, them when you need to use the van, just take that with you and use a set of (decent) jump leads to fire it up, then disconnect the spare battery. The alternator will then do it's job in charging up the normal starter battery as you drive. Just don't let the main battery fall much below a reading of around 11.8Volts or it will be adversely affected.

p.s. - just saw your last post re the weather. As far as I know, and in my experience, cold weather shouldn't cause a battery to go flat any faster than in warm weather (though it does cause a battery to be unable to produce as many starting Amps as compared to warmer conditions).

Re: Best Battery and Charger for Standby Battery

Posted: 10 Jan 2016, 13:07
by CJH
Ah, alarm, ok. That'll probably do it. Consider pulling the fuse for the radio then - that may help. With a multimeter you'll be able to check the impact. Disconnect the battery negative cable and put your multimeter between the cable and the battery terminal. Measure the current draw under normal conditions (don't start or run the engine like this), and then remove the radio fuse and check the current draw again. To give an idea, 100mA (0.1A) will draw 2.4AH in a day. A 70AH battery will give you 30-40AH before it's effectively flat, so about two weeks at 100mA.

If you've been regularly flattening your battery then it may well be losing it's ability to hold a charge. As Ghost would say, if you've got a voltmeter, give the battery a good long charge, then let it stand and watch the voltage drop over the next 24 hours. If it can't hold 12.7V or thereabouts after 24 hours it may be on its way out.

Re: Best Battery and Charger for Standby Battery

Posted: 10 Jan 2016, 13:18
by Paule39
ghost123uk wrote:Or just keep a half decent, well charged battery at home, them when you need to use the van, just take that with you and use a set of (decent) jump leads to fire it up, then disconnect the spare battery. The alternator will then do it's job in charging up the normal starter battery as you drive. Just don't let the main battery fall much below a reading of around 11.8Volts or it will be adversely affected.

Thanks - I thought doing that would eventually knacker the battery though (i.e. regular jump starts)?

ghost123uk wrote: p.s. - just saw your last post re the weather. As far as I know, and in my experience, cold weather shouldn't cause a battery to go flat any faster than in warm weather (though it does cause a battery to be unable to produce as many starting Amps as compared to warmer conditions).

You might be right - it was 11.5v this morning and wouldn't start, so had to jump start it,,,

Re: Best Battery and Charger for Standby Battery

Posted: 10 Jan 2016, 13:21
by Paule39
CJH wrote:Ah, alarm, ok. That'll probably do it. Consider pulling the fuse for the radio then - that may help. With a multimeter you'll be able to check the impact. Disconnect the battery negative cable and put your multimeter between the cable and the battery terminal. Measure the current draw under normal conditions (don't start or run the engine like this), and then remove the radio fuse and check the current draw again. To give an idea, 100mA (0.1A) will draw 2.4AH in a day. A 70AH battery will give you 30-40AH before it's effectively flat, so about two weeks at 100mA.

If you've been regularly flattening your battery then it may well be losing it's ability to hold a charge. As Ghost would say, if you've got a voltmeter, give the battery a good long charge, then let it stand and watch the voltage drop over the next 24 hours. If it can't hold 12.7V or thereabouts after 24 hours it may be on its way out.

Thanks. Do you know which fuse is the radio one? I'll take battery to Halfords to get it tested - they did it 3 months ago and said it was in good condition, so hopefully it will be ok. I will check tomorrow and see what the reading is

Re: Best Battery and Charger for Standby Battery

Posted: 10 Jan 2016, 15:43
by BOXY
If you keep running the battery flat (below 12.0v) you'll shorten its working life. That's why I said just get a couple of scrapyard batteries for a £10 each and it won't matter if you kill them. I've actually got a 75aH battery that is too big to fit under the seat just sat in the back of the van on the floor in the winter. Like Ghost suggested, I use this to jump the van if the normal batteries can't turn the van over. The last time I charged it was about 3 months ago and I've jumped the van off it twice in the last 8 weeks, and its still showing 12.6v. Leaving it in the van is no hassle, and it keeps the cupboard door shut ;)

Out of interest does the sterling charger pull a current when its left connected? I fitted a Ctek charger for charging my starter battery off the hook up and according to the manual it has a Back current drain* <1Ah/month.

Re: Best Battery and Charger for Standby Battery

Posted: 10 Jan 2016, 16:03
by Paule39
BOXY wrote:If you keep running the battery flat (below 12.0v) you'll shorten its working life. That's why I said just get a couple of scrapyard batteries for a £10 each and it won't matter if you kill them. I've actually got a 75aH battery that is too big to fit under the seat just sat in the back of the van on the floor in the winter. Like Ghost suggested, I use this to jump the van if the normal batteries can't turn the van over. The last time I charged it was about 3 months ago and I've jumped the van off it twice in the last 8 weeks, and its still showing 12.6v. Leaving it in the van is no hassle, and it keeps the cupboard door shut ;)

Out of interest does the sterling charger pull a current when its left connected? I fitted a Ctek charger for charging my starter battery off the hook up and according to the manual it has a Back current drain* <1Ah/month.

OK, that could be an option thanks - (the 75ah). Not sure if the sterling pulls a current (I don't think it does), but will have to check that as well as the radio.....!

Re: Best Battery and Charger for Standby Battery

Posted: 10 Jan 2016, 18:25
by California Dreamin
I can't believe that nobody has mentioned 'SOLAR'
£140.00 or there about's, for a 'fit and forget' 100 watt panel, wiring and dual output controller and that's it! Never have a flat battery again. Plus other benefits like saving on electric hookup and not needing to charge leisure batteries when the van is laid up.

Martin

Re: Best Battery and Charger for Standby Battery

Posted: 10 Jan 2016, 18:42
by ethelred the ready
Yes, I did this with a second hand solar panel. Keeps both battery charged, cost about£60 for bits and about two hours work. Now van always has full batterys and starts easy.

Re: Best Battery and Charger for Standby Battery

Posted: 10 Jan 2016, 19:11
by Paule39
California Dreamin wrote:I can't believe that nobody has mentioned 'SOLAR'
£140.00 or there about's, for a 'fit and forget' 100 watt panel, wiring and dual output controller and that's it! Never have a flat battery again. Plus other benefits like saving on electric hookup and not needing to charge leisure batteries when the van is laid up.

Martin

Have you seen the weather lately?! I forgotten what the sun looks like! :D :D I could look at Solar, but not that technical, so unsure on the fitting tbh :x

Re: Best Battery and Charger for Standby Battery

Posted: 10 Jan 2016, 19:33
by Oldiebut goodie
You don't need sun to get a charge - you will still get something when overcast just not as much as a full on sunny day.