Battery Issue

[Stonelynk]

hi all I am new to Motorhome Fun and have only had a motorhome for about 10 months, but need some guidance on what to do with the electrics (batteries) when not in use. I disconnected the negative on both the leisure and main batteries and attached a battery conditioner to the main battery. When I reconnected to turn it over, dead. What am I doing wrong? Please help.

 

[Podney]

What’s a battery conditioner?

 

[ctc]

Sounds like a charger in reverse.

 

[pappajohn]

A disconnected battery should remain charged for a considerable time, think how long they are on the shelf in motoring shops, so it sounds like a charger issue draining it or the battery itself is shot
Only way of knowing is charge it with a proper charger while disconnected for a couple of days, remove from charge and leave it overnight then check the voltage with a multimeter.
The meter should show around 12.7v if the battery is good.

Or.... It may just be you had a really poor connection when you reconnected.
A 300/400amp load will soon break a bad connection.

 

[Stonelynk]

Many thanks for relies. The battery isa new one, as i was not aware the the original battery history. I did only disconnect the negatives, but now fully disconnected and on charge. So will see what happens. I am assuming that it is best to fully disconnect if the van will not be used for some time. I do use a battery conditioner which monitors the battery and will trickle charge when needed. I did use this successfully on a BMW Z3 previously.

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[pappajohn]

Disconnecting earth only will be adequate but be aware if you have an alarm/immobiliser it won't be active once the battery is disconnected.
Your maintenance charger should be on constant trickle once the battery is fully charged.... Not just as it discharges.
As the name suggests..... It maintains the battery in a fully charged state.

If the battery is new and good it does sound like a bad connection.

 

[ambulancekidd]

Many thanks for relies. The battery isa new one, as i was not aware the the original battery history. I did only disconnect the negatives, but now fully disconnected and on charge. So will see what happens. I am assuming that it is best to fully disconnect if the van will not be used for some time. I do use a battery conditioner which monitors the battery and will trickle charge when needed. I did use this successfully on a BMW Z3 previously.

Am I right in assuming that you store your moho at home?
If so why not leave the electric hookup cable permanently plugged in, that way the moho's own charger will do its job of looking after the battery.
There really is no need for a battery conditioner of any type.

 

[pappajohn]

Am I right in assuming that you store your moho at home?
If so why not leave the electric hookup cable permanently plugged in, that way the moho's own charger will do its job of looking after the battery.
There really is no need for a battery conditioner of any type.

Maybe not configured to charge the engine battery which is the problem in this case.

 

[autorouter]

I disconnected the negative on both the leisure and main batteries and attached a battery conditioner to the main battery.

What is the make and model of the battery conditioner?

When I reconnected to turn it over, dead. What am I doing wrong? Please help.

Are you sure it's the battery that's flat? Can you check with a multimeter? I'm asking this because it might be that the immobiliser is preventing you from turning the engine over. Maybe disconnecting the battery for a few hours has caused a problem.