If folks are like me and do not have that 50A or 30A receptacle to plug into when your Barth is sitting in the yard, Battery Tender has a solution that I have just installed and it works great. Mind you, my coach sits in the yard with everything off when not in use. This idea is just for those who are like me and park your coach between trips. When parked between summer outings, I feel that the only thing I need to do is keep the batteries in the coach at a full charge. Yea, I could use the kill switch in the coach to save the batteries from draining (though they will on their own over a period of time anyway), but that is unnecessary. Battery Tender makes a two bank charger. I mounted the charger in my compartment with the coach batteries. I purchased a 12' extension cable from Battery Tender and ran it over to the compartment with the chassis batteries. Now all I have to do while it is sitting in the yard is run a standard outdoor extension cord to the Battery Tender charger and plug it in. I can also do this while I'm sitting at the campground. From that point on all my batteries are kept up to charge and I do not have to mess with anything else. And yes, it will keep both of your paralleled batteries charged. All this convenience for under $100!

Bruce...That would work well im my situation also. What model did you get? Where? .. Thanks Gerald

E-Bay....my favorite shopping place. Do a search for Deltran part #220165. Different deals to be had. There is a deal on there right now that you can buy the charger with (2) 25' lead extensions for $97.95 (free shipping). Or the deal I got was the charger for $82.40 (free shipping) and then I bought the 12' lead extension from someone else for 12.70 with shipping. So the "package deal" is well worth it, though you will end up with 25' extensions...

Old topic..

Still the preferred battery tender or what’s todays recommendation..?

Old Topic take 2..

Will a 12V battery tender work on the chassis batteries, 2 each in series hooked to #1 battery positive and # 2 battery negative or should I get a dedicated 24 volt tender same hook up pattern..?

Seems a single 12V charger/tender spread over 2 , in series 12 Volts batteries ( equaling 24 volts.. ) might not have the 'umpth' to do the job..
for house system batteries the isolator would bring it back down to 12Volts,

Thoughts and recommendations...?

a link discussing options...

All typical coach battery systems use 12V.

There are usually two separate battery sets, one 12V set for starting and another 12V set for the coach. (Some smaller rigs will have a single 12V battery for each system, but most will have two or more 12V batteries connected in parallel for each system.)
see Figure 3 in previous post link

These two sets are usually isolated from each other, so that if you run the coach batteries down you can still start the engine with the starter batteries.

Generally, the starter batteries are charged by the engine alternator and the coach batteries are charged by a 110AC to 12VDC convertor/charger. Each set is separately connected to its charging source as in Figure 9.

In theory, if both battery sets are the same type they could all be connected in parallel and charged from a single 12V charger. This defeats the purpose of having separate sets, since they would then be all tied together as a single set.

Also, the two battery sets may be different battery types, ie starting batteries for high amp short duration starting and deep cycle coach batteries for extended low current drain. This is another reason to keep them isolated, since each type has different charging characteristics.

Leaving the coach plugged in will usually keep the coach batteries fully charged but not the starting set. (Some newer coach chargers are actually two chargers in one, with a separate 12V charger for each set. These will keep both sets charged.)

Some coaches have a so called battery isolator connected to the engine alternator, allowing both the starting and coach batteries to share the alternator output when the engine is running, but remain isolated from each other when not running. Again not the best if the two sets are different battery types.

Usually, if the coach remains plugged in to 110VAC, the convertor will keep the coach batteries charged. A small separate 12V charger can be connected to the starting set to keep them charged as well.

In no case would series connections and a 24V charger be used. Series/parallel sets are used for golf carts, backup power systems using large high voltage, high current loads.

If your coach has a charger or solar panels for the coach batteries, there is a device which will keep the starting batteries charged also.

Basically it attaches a + lead to each battery set, and one to ground. Once the coach batteries are charged, it sends the current to the starting batteries. They remain isolated but it will provide up to 10 amps to the starting set until they too are charged. It requires no power of its own since it runs as a piggyback from the coach batteries. Very easy to install, only 3 wires.

TRIK-L-START

http://www.lslproducts.net/TLSPage.html

There was one on my coach when I bought it and it works well.

(I have always liked chicken tenders better than battery tenders.)

Saw the post and did not know if some of the diesel coaches used a 24volt system for the house system, happy you had the info as usual, even if you are in Florida!!

To my knowledge, none of the older coaches were 24V. Lots of airplanes and military vehicles are.

I would imagine your engine starting system is 12 volts . You should be able to put a 12 volt battery tender directly to the batteries . Ours has a master cutoff switch at the engine starting or "coach" batteries . When parking it for a while , I turn it off to disconnect the batteries . I haven't needed a battery tender , but it would be easy to add . We have them on some of our fire apparatus . Some of them must be unplugged before starting the engine or they will be damaged by the current from the alternator .
It will tell you in the instructions that come with the battery tender if that is the case .

Our Breakaway has mostly set for the past two years. The solar keep the house batteries charged. Engine batteries will slowly drain down. I have a 14gauge jumper wire that I will sometime run from the house a batteries to the engine batteries. Works just fine but need to remove the jumper if going to start the engine because of current draw.

TRIK-L-START

Now that looks pretty nifty

My solar charger/controller has a separate coach lead that when the house is fully charged it will charge the coach batteries.

One thing I did not see mentioned in this discussion is a battery combiner. I have one on my coach and it charges both the house batteries and the starting battery whenever it senses a charge from either the engine alternator or the inverter/charger (or converter/charger) and then disconnects the two banks when it is not charging.
This has worked well for me, just something else to consider.

Battery combiners work well if the battery sets are similar.

With wet cells, starting and deep cycle types are somewhat different in charging characteristics. AGMs are also not the same, and lithium cells are much different.

Battery combiners are certainly better than leaving the batteries uncharged, but as noted, they will usually not fully charge all batteries if the sets have different battery types.