'05 V70R long term battery disconnect

Help, Advice, Owners' Discussion and DIY Tutorials on Volvo's stylish, distinctive P2 platform cars sold as model years 2001-2007 (North American market year designations).

2001 - 2007 V70
2001 - 2004 V70 XC (Cross Country)
2004 - 2007 XC70 (Cross Country)
2001 - 2009 S60
2003 - 2007 S60 R
2004 - 2007 V70 R

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'05 V70R long term battery disconnect

Post by cypilot »

I use our 2005 V70R as a jobsite car, and it frequently sits for 3-4 weeks without being run. In the past I've used a solar 12v battery charger to keep juice in the battery, but that's proved to be unreliable.
Is there any disadvantage to just disconnecting the battery while it sits? I'm assuming I'll lose the radio and clock settings, but that's no big deal to me.

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Post by RickHaleParker »

Get a bigger 12V Flexible Solar Panel(s) and mount flat on the roof. Use a adjustable Buck converter to regulate the voltage to a float charge voltage of 13.5V. There is enough room up there to get more then one 100W panel mounted. Plenty of power to top off the battery each day.

You can find both the panels and Buck Converter on eBay. A 100W panel will run about $75.00 - $100. T . A suitable Buck Converter for less then $10.00.

100W Flex Solar Panel $99.00. Buck Converter $5.98.


Last edited by RickHaleParker on Tue Oct 13, 2020 5:29 am, edited 4 times in total.
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Post by abscate »

If you disconnect the battery you reset the ECU codes and adaptives so the car might drive a bit funny at first. No damage

I put a knife switch on one car while I struggled diagnosing a drain problem so I could quickly disconnect the battery without tools
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Post by cn90 »

You may not be able to open the trunk if you d/c battery. No big deal, just climb through rear seats.

You will lose clock setting and that is all.

Solar charger: place it inside the car. Not on the roof. The problem is: the cig socket is switched (in contrast, BMW cig socket is hot all the time).

Easiest is to d/c battery and lock the doors.
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Post by oragex »

As above, unfortunately the V70 doesn't have trunk lock for some weird reason (all S60 and S80 had it) so you'll need gymnastic skills to connect back the battery (flipping the rear bench is easy in the V70). Be sure first the door lock works mechanically. There are remote battery switches but it's $200 You are much better to store the car with the battery disconnected (have the key in POSII when reconnecting), constant battery discharge will damage it plus you risk the immobilizer problem www.youtube.com/watch?v=rDyxtusEs2Q

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