# Swift Kontiki leisure battery



## the-teuchters (Oct 5, 2010)

We've just changed our previous MH to a 'new to us' Swift Kontiki and all in all v.pleased with it.

However I'm a bit dubious about the leisure battery. On a fully charged 90 a/h battery with a 60 watt discharge how long should the voltage stay above 12v? Testing it this afternoon it has dropped to 11.8 in 4 hours!


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## Pudsey_Bear (Sep 25, 2008)

What did it measure when it was "fully charged" as that = 5 amps (I think) which on a smallish battery while not a lot will be noticable


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## the-teuchters (Oct 5, 2010)

Thanks.......it was 12.5 (fully charged off the hookup)


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## wakk44 (Jun 15, 2006)

By my calculations you have discharged the battery at a rate of 5 A/H for 4 hours =20A taken from the battery.So a fully charged 90 A/H battery should be down to around 70 A/H.

This equates to around 75% of your 90 A/H battery.Checking the following battery discharge chart.......









the battery terminal voltage should be down to around 12.3v-12.4v after your discharge test,there are other variables to consider such as temperature and the accuracy of your multimeter.


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## rayc (Jun 3, 2008)

the-teuchters said:


> Thanks.......it was 12.5 (fully charged off the hookup)


With reference to Steve's table of voltage against % charge, I wonder if your battery was fully charged at the start. Could you repeat the charge and switch the charger off. Isolate the battery from the circuits and measure the voltage at the battery terminals 30 mins after the end of charging. That would be your start point.


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## the-teuchters (Oct 5, 2010)

After 8 hrs battery level under load (60 watts) was down to 11.3v. On removal of load battery level recovered immediately to 11.9v. Which figure should be used?

If 11.9, battery probably OK(ish) as the temp. during test only about 5 Deg C.

Battery now back on charge through hook-up. (Got the wind up when I saw the 11.3v!).

So, assuming battery OK(ish), on to the real problem. We are using a 12v 600w Nikkai inverter to run our 230v 60w television, but it won't go for long before the inverter trips out [low battery alert (11.5v I think)] I'm guessing the inverter is drawing about 100w on the 12v (in) side, so assuming the inverter is not faulty it would suggest I need to double up on leisure battery capacity when wild camping. (can't run the engine all night!)


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## spatz1 (May 19, 2011)

optimally charged a new 90ah will give 90ah.....

yours isnt new and youve only measured 12.5v and taken it as fully charged....

my 2x110ah give a voltage of 12.9 a day after charging and i only deem them fully charged when they draw less than 12watts from the van charger,boost charger or both on together in the final stage of charge...

i m guessing you were 20ah down on a 90ah battery at 12.5 before you even started the test or put your tv on....


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## Pudsey_Bear (Sep 25, 2008)

We use a either a 150w or 300w for TV use as there is less overhead.
" x 110ah + a 40w panel, wild camping is fine with that setup if used sensibly.

Using LED lighting, TV, and a PVR, (both on 240v transformers for 3-4 hours) pump for 2 showers and washing up, (in summer) the battery drops to around 70-75% observed before going to sleep, but is usually almost back up to 100% by 9am, we can stay put for as long as the water & waste tanks last.

Spring autumn and winter obviously less long due to greater use of heating, lights, and the cooling effect on the batteries.


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## denisl (Mar 16, 2011)

the-teuchters, to answer your question. When using the battery voltage as an indicator of state of charge, the battery should have been at rest (niether charging or discharging) for some time time - I would give it two or three hours.

So you should at least use the higher of your two voltages, which would possibly have risen a bit higher.


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## the-teuchters (Oct 5, 2010)

Have come to the conclusion that the battery is ok so no need to get on to the dealer about it. I'll buy another battery to double up.

Looks like a solar panel was fitted previously, all wiring is in place so will post later on advice for possible purchase in the future.

Thanks all............. from the-teuchters in the beautiful snowy West Highlands


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