battery charging

[donna and daz]

Can anyone help, every time we go to our van the leisure battery is dead, (approx every three weeks). We would like to buy a charger, can anyone recommend one either that can be left in the van solar power etc, or one that we use via mains at home? :-S Thanks Donna and Daz

[tp002c784tp002c784tp]

Hi donna & daz Sounds like something is discharging your Battery could you be leaving something on ? I have a 75watt solar panel on my M/H had it for a few years now best thing I ever bought and this year has been the best year for keeping it charged up plenty of sunshine this year although you don,t always need bright sun to get at least a little bit charge going in, also carry a generator when on Hol,s but no need for it this year Terry P (lol) *-)

[Brian Kirby]

Bit difficult to say.  What is the van?  As you visit it, I assume it isn't stored at home.  However, if you could leave the battery on charge, I assume you can connect to electricity.  In that case, why don't you just leave the van on hook up?  Is there no built in charger? 

If you do have to leave it standing with no hook up, a charger won't help in any case.  A solar panel may, but it'll cost!

Something is discharging your battery.  Could it be a radio, or a Truma frost protection valve, or an alarm?  If either of the former, why not isolate the radio supply or, if it's the Truma bit, drain down the heater and leave the valve open?

You could also, unless you have something vital like an alarm, that is using the habitation battery to keep it "alive", install an isolating switch on the battery and just turn that off when leaving the van.  Much cheaper than solar panels!

If there is no load on the battery, is it perhaps just an old battery, that won't hold its charge.  Might be worth checking before you spend money on the wrong thing!

Hope this helps

[Westy]

You have my greatest sympathy but no solution. We have the same problem with the vehicle battery. If the van is not run every 3 or 4 days, which is not practical, we have a flat battery. We have just been parked for 4 days at a site in Germany, when we wanted to move sites - totally flat and had to call out the breakdown people. It you find a solution please let us know. Our van is only a year old and because of the problem right at the beginning the dealers did change the battery but obviously it still has a fault and it's now very irritating.

[Basil]

We use a small charger of the type used for motorcycle batteries, called Optimate, this is safe to leave on charge all the time and is a four stage charger, that is on constantly when on mains hook up. When we are not on mains hook up we have the ability to use either battery for leisure use or starting and, so far, we have not had a problem. Bas

[JohnP]

Another thing which can discharge the leasure battery is the light staying on in the fridge.

[Brian Kirby]

[QUOTE]Westy - 2006-08-28 9:50 PM You have my greatest sympathy but no solution. We have the same problem with the vehicle battery. If the van is not run every 3 or 4 days, which is not practical, we have a flat battery. We have just been parked for 4 days at a site in Germany, when we wanted to move sites - totally flat and had to call out the breakdown people. It you find a solution please let us know. Our van is only a year old and because of the problem right at the beginning the dealers did change the battery but obviously it still has a fault and it's now very irritating.[/QUOTE]

Westy

Donna and Daz have a problem with their leisure battery.  Yours is with your starter battery.  In fact, even the habitation battery should survive for 4 days without going flat. 

You should return your van to the dealer from whom you bought it pronto, and insist they fix the problem.  Prerhaps, as the fault is with the starter battery, it should go to a service centre for whatever make the base vehicle is.  However, the dealer you bought from should make this arrangement since, if there is a fault in the conversion wiring the base vehicle warranty won't cover it, and you won't want to be stuck with the bill and then trying to get the money back from the the motorhome dealer.

Are you sure it is, actually charging properly when the engine is running? 

Failing that, something is connected to your starter battery when it shouldn't be.  Are you using the 12V socket in the cab for anything?  That is usually connected to the starter battery, and extensive use might drain the battery. 

I assume you don't have one of these "magic" fridges that mysteriously "run" on 12V for ages, do you?  If you do, suspect the fridge relay, which should disconnect the alternator/starter battery as soon as the engine is switched off.

If you can't find anything obvious, back the the dealer!  It's what warrantys are for!

Hope this helps.

[euroanchor]

Make sure that if you've got a sat nav unit fitted, that it is not wired so that the receiver is continously live,this drains batteries quicker than you would imagine, I had this problem on my car and it took me forever to suss it. If you can switch it on without the ignition, then this could be part of your problem.

[Mel E]

To keep your batteries topped up , proceed as follows: 1. Buy a proper car battery charger that automatically switches itself on/off when it detects the charged battery voltage is adequate/ inadequate. Available at any good auto dealers. Connect to the leisure battery. (This is better than connecting to the vehicle battery as modern ECUs can be damaged if a spike voltage reaches the battery and hence the ECU). 2. Connect a single wire (preferably red, with crocodile clips on both ends) between the live terminals of your vehicle and leisure batteries. No need to connect the negative side as they are already connected through the vehicle chassis. 3. If a solar panel is fitted, proceed as above, but you have no need to buy and connect the charger. 4. Place a clear notice on the steering wheel warning you to remove the vehicle to leisure connection and the charger (if fitted) before starting the engine. This is better than leaving the vehicle on hookup, as the leisure battery mains chargers - especially in older 'vans - do not necessarily cut out when the betteries reach full charge, but go on trickle charging them. This will eventually cause the batteries to gas themselves dry - I know 'cos I've been there!

[V6Jim]

Just bought myself a 5W solar panel on Ebay for £20! This is a smallish portable panel that I'm going to sit on the dashboard during layoff periods. I can connect it in a variety of ways: 1. Crock clips onto the vehicle battery. 2. Crocks onto the leisure battery. 3. Connect it to the output from the internal mains run 12V charger. (Charge both batteries at the same time) I realise it'll just pop about a half amp into the battery, but this will be plenty to maintain the whole system painlessly during storage. In time, I could buy more of these panels, or a single bigger one and mount them permanently on the roof. 50W would be nice...... Hope this helps. Jimmy

[Mel E]

V6Jim, Sorry to have to disappoint you, V6, but actually you'll get about one-third of an amp (solar panels are rated typically at 16.5 volts to be able to push power into the battery, so 5/16.5 = 0.3 amps. And that is only under full summer sun vertically at right angles to the panel surface. With the panel flat on the dash board, on a typically light cloudy day during the UK winter, you'll get about 0.4 amp hours in 24 hours, on a dark cloudy day half that, and even on a sunny day you'll get less than one amp hour per day. This is because of the low angle of the sun affecting both the amount that the panel 'sees' and the poor transmissivity of the atmosphere at low angles, especially when cloud is present, but also, even in bright sun light. So it depends on the battery drainage. But based on a single 80 amp hour battery, charged (fully) to about 65 amp hours and draining down to 15 amp hours in, say 4 weeks, that's a loss of 2 amp hours per day. With only two such batteries (one leisure and one engine), you're losing 4 amp hours per day. And that's without any exceptional drainage such as an alarm system or GPS tracker system. So you'll need to keep it well tilted towards the south to stand any chance of achieving your purpose. But the price wasn't too bad - cheaper than Maplins!

[V6Jim]

You're absolutely right, there is a fair chance that this may not work. I'll give it a go and see what happens. I'll check things regularly with the trusty Voltmeter. I may invest in a big one for the roof if this one proves good quality. Jimmy

[michele]

john p, oh not again, poor goatie. (lol)

[JohnP]

2006BG (Before Goatie) Yes Michele it happened with a tugger at a rally recently and had caused a flat battery over the previous four weekends. Took a long time to diagnose.

[michele]

[QUOTE]JohnP - 2006-08-28 11:36 PM Another thing which can discharge the leasure battery is the light staying on in the fridge. [/QUOTE] john sorry I was taking the mick out of Geoff & his fridge light, but yes we used to leave our's up the stables free you see used to jam it in fron't of the giant horse boxes . harder to steel with the front up to a brick wall . When I was there mucking out no problem's but go home at night turn's out the battery was being drained by the alarm. It's on the drive now (We had the builders in at the time)... Regards

[Guest starspirit]

I had a similar problem with an A/S Talisman several years ago. Never did find it in spite of many goes - so I fitted an isolating switch close to the leisure battery which turned it off when not in use. That worked! And t'was cheap and dependable too! I used my infamous'Terry' clip on the steering wheel to reind me when it was off and the clip sat by the switch when on so that I would not forget to put the clip on the wheel! Simple init - jus' like me! I also carried a small and light cheapy 12 V car battery as an emergency spare which I could plug into the system to keep the lights and water pump going when all else failed. Again low cost, frowned upon by experts, but it works!

[V6Jim]

[QUOTE]V6Jim - 2006-09-04 8:18 PM You're absolutely right, there is a fair chance that this may not work. I'll give it a go and see what happens. I'll check things regularly with the trusty Voltmeter. I may invest in a big one for the roof if this one proves good quality. Jimmy[/QUOTE] Got the panel this morning. It's very small (320mm x 250mm) but is nicely made. It has a non return diode and about 3 feet of cable and that's that. Ok though as it cost a total of £26. Here is the link to the item on eBay: http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ih=006&item=160025298961&rd=1&sspagename=STRK%3AMEWA%3AIT&rd=1 Connected two crock clips I had lying about and included a digital Ammeter in the charging circuit. Hooked it all up and took the following readings: Battery voltage at rest before connection. 12.45V. Panel Open Voltage 22.2V. (Bright weather but not in direct sun) Battery voltage after 15mins. 12.79V. Current Draw 230mA. Battery after 60 mins. 13.08V. Current 227mA. Battery after 120 mins. 13.3V. Current 222mA. Voltage seemed to settle at this level as the sun descended during the afternoon. All this with bright, but not sunny weather. The figures would imply that the panel is actually working at about 3W and not 5W as suggested. In bright sun this may improve. However, I am quite satisfied that it should be able to maintain a battery at a reasonable voltage over lengthy storage periods. This same eBay seller has a 65W Crystalline Panel for £200 which seems pretty fair. Would need a charge regulator too, but they're not expensive. Quite happy.... Jimmy

[Mel E]

V6 Jim, I guess the lower charge rate is because the sun was at an angle to the panel. Note that 65 watt panels are usually 70 or 75 watt panels that have failed testing and so are downrated. They are usually good value therefore, as their price is usually quite a lot less than pro-rata to the watts.

[griffly16]

Sorry to be ignorant, but can you leave the panel attached (almost) indefinitely without damaging the battery?

[Terrytraveller]

Hi Griff, If your panel is around 12 watts you can leave attached all the time, if your solar panel is much above 12 watts you really need a regulator in the circuit to prevent over charging of the battery. My set up is 80 watts with a 10 amp regulator, when fully charged the voltage is 14.4 volts at the battery (bright sunshine), the trickle charge at this time is 400 mA (0.4amps). The battery needs checking four times a year and will consume one litre of distilled water in 12 months. The battery is a 110amp Elecsol carbon fibre type, and is coming up to 5 years old, still in good condition. The solar panel output (input at the regulator) is 18.5 volts when the battery is fully charged. The solar panel output with regulator disconnected is 22 volts. Regards Terry

[Mel E]

Terry, That's veeeeerrry interesting. I too was persuaded to buy a (very expensive) Elecsol battery and found that it needed constant topping up. Got rid of it in the end. I've had solar panels (properly regulated) for years, and ordinary lead acid batteries do not have this problem - no need to top up from one year end to the next. And you can get 85 amp hour ones for around £25 at shows that seem to last for at least 5 years, which is all the guarantee you get with Elecsol. I have concluded that it's more important to have matching batteries than expensive ones!