Jack,
Review the various posts on this earlier topic on this forum at this direct website address link:
http://www.bornfreervclub.org/bulletin_ ... te&start=0
Please note that you could replace your Interstate SRM-27 batteries easily with the larger SRM-29 batteries in the existing holder. Please note the probably the most damage to your coach batteries comes from being plugged in too long into shore line power causing your Magnetek/Parallax 7345 Charger/Converter to over-charge your batteries and boil them dry.
If you want to use a trickle charger to keep your coach batteries charged during long periods of storage but not over-charge them and boil the water out of your batteries, then I would recommend the Battery Minder. Check the product out at this factory website address:
http://www.vdcelectronics.com/batteryminder_12112.htm
You can order it from the factory for $59.95 I believe or you can currently order it from Camping World at a cost I believe of $44.99. Refer to Camping World website address:
http://www.campingworld.com/browse/skus ... unum=31590
Or, like recommended above you should consider changing out your Magnetek/Parallax 7345 Charger/Converter to a new 3-stage smart Charger/Converter such as the Progressive Dynamics PD9160A or similar system. You can use it safely to keep your coach batteries fully charged by just plugging your coach into shore line power without the problem of boiling the batteries dry. I have a detailed procedure for doing this conversion, if you want to consider doing it, at this website address:
http://home.earthlink.net/~whemme/
_________________
Bill Hemme - Spencer, Iowa
E-mail:
whemme@earthlink.net2002 Born Free (Ford E-450 V10) 26' RSB
2016 VW Golf GTI - toad