4D battery

[LARufus]

The house battery in our van is not able to hold a charge, I believe it may be original-2005. Since we brought it home last week have been keeping it plugged in which I assume is charging van Battery and house battery. If not plugged in toggle switch on dash has to be flipped (learned this the hard way) or will drain van battery.

We plan to mostly camp at campgrounds where 30a hookups are available.
How important is it to change this 4d battery? I don’t want to ruin the agm van battery as it is a 2020. Is it okay to leave van plugged in when in storage?

[gahamby]

Well I typed up a nice reply and got logged out, dang! Yeah, replace the old house battery, check the function on the combiner switch, and consult the manual on your charger for long term storage.

[LARufus]

Thanks, will replace and do some more reading. Fortunately the previous owners maintained all original manuals and also has original paperwork from Sportmobile build.

[arctictraveller]

You will want the house battery, even if you almost always camp at spots with power. No doubt there will be times when you don't get power, or simply want to stop for a rest at night, and without a house battery none of your 12 accessories like lights will work unless the motor is running. And besides, there are plenty of awesome campsites without power. Also, its best to have all battery's of the same type. With an AGM start battery, you should also have an AGM house battery because different battery chemistry's require slightly different charging parameters.

[daveb]

Originally Posted by LARufus

The house battery in our van is not able to hold a charge, I believe it may be original-2005. Since we brought it home last week have been keeping it plugged in which I assume is charging van Battery and house battery. If not plugged in toggle switch on dash has to be flipped (learned this the hard way) or will drain van battery.

We plan to mostly camp at campgrounds where 30a hookups are available.
How important is it to change this 4d battery? I don’t want to ruin the agm van battery as it is a 2020. Is it okay to leave van plugged in when in storage?

Kinda depends. Do you have a charging isolator, or a separator relay such as the Surepower model? Also does you van have a inverter or a converter? That info should be in your manual.



It's hard to say w/o looking at your layout but guess that toggle switch is a way to force the separator to stay open or closed. If you set it to stay open (like you are saying), plugging into shore power and starting the charger will only allow the house battery to charge. In 2005 SMB was using Surepower separators on many of their builds.



I would just replace the house battery with the same AH size that is in there. Make sure the new battery is also physically sized the same if it's in a tight fit box and has the same type power lugs. When you drive, the alternator should be charging both batteries if everything is working correctly. When in storage it's best to trickle charge but if the on board charger is high amp, just periodically charge the whole system. It's best to daily monitor a higher amp charge rather than setting it to on for long periods of time. Most high amp chargers are automatic and ramp down but I'd never take a chance leaving it charging for weeks. With a standalone low amp trickle charger (sometimes called a maintenance charger) you can use those to supply a very light charge while the van is in storage.



There are also ways to permanently remove the house battery altogether but would require more info on your particular DC system.



I'm curious to how your fridge is working without a house battery when you turn off the vehicle before hooking to shore power.

[LARufus]

Originally Posted by daveb

Kinda depends. Do you have a charging isolator, or a separator relay such as the Surepower model? Also does you van have a inverter or a converter? That info should be in your manual.



It's hard to say w/o looking at your layout but guess that toggle switch is a way to force the separator to stay open or closed. If you set it to stay open (like you are saying), plugging into shore power and starting the charger will only allow the house battery to charge. In 2005 SMB was using Surepower separators on many of their builds.



I would just replace the house battery with the same AH size that is in there. Make sure the new battery is also physically sized the same if it's in a tight fit box and has the same type power lugs. When you drive, the alternator should be charging both batteries if everything is working correctly. When in storage it's best to trickle charge but if the on board charger is high amp, just periodically charge the whole system. It's best to daily monitor a higher amp charge rather than setting it to on for long periods of time. Most high amp chargers are automatic and ramp down but I'd never take a chance leaving it charging for weeks. With a standalone low amp trickle charger (sometimes called a maintenance charger) you can use those to supply a very light charge while the van is in storage.

I'm curious to how your fridge is working without a house battery when you turn off the vehicle before hooking to shore power.

I have a inteli power 9100 with a charge wizard which is a converter and monitor-charging module. By looking at charge meter it is reading van voltage as it stays around 13.5.

Not sure about the refrigerator, i assume it is running of the van battery at that stage. I have it turned off at the controls.

I am going to get a new battery in there soon. As for batteries is there a specific brand? I understand amp hrs, post and type. I run west marine agm in my boat and can get locally.

[86Scotty]

I'd replace, stuff will act funny with a dead battery in the system. Just replace with an inexpensive lead acid 4d from Batteries n Bulbs or the like, $150 on the website now. I always get a 10% off link on their website so I purchase online and drive over to the store.



https://www.batteriesplus.com/productdetails/sli4da

[SteveInLA]

If you are not buying an exact brand replacement, be sure to check the measurements of the battery you are buying. I bought a Recology 4D AGM battery to replace mine and it ended up being wider than my original. I had a new shelf fabricated since I couldn't return the battery but I would have liked to not have had to do that.

[LARufus]

Originally Posted by SteveInLA

If you are not buying an exact brand replacement, be sure to check the measurements of the battery you are buying. I bought a Recology 4D AGM battery to replace mine and it ended up being wider than my original. I had a new shelf fabricated since I couldn't return the battery but I would have liked to not have had to do that.

Ended up going with a West Marine 4d agm battery, fortunately it was same size. The old battery was a 2012! No wonder it was bad. Previous owner I’m sure installed it when he purchased.

It was a learning experience changing out this battery. Hopefully next time it will be a little easier.