House Battery Replacement Procedure

[Jeff Watt]

Going to be changing out the 4 house batteries this weekend. I just wanted to run my procedure by all to see if I am doing it correctly or need to do anything else:

Disconnect shore power,
disable solar (will be in shed so zero or minimal solar but still may try to find fuse and remove),
turn house battery disconnect switch off,
turn inverter breaker off in case of residual power,
take pictures
remove negative cables first

after install, then reverse this procedure (other than negative cables go on last) and check charge status.

Do wonder if I should turn the engine battery switch off? Will be a few (5+) hours from the time of removal to replacement - have to take old batteries out, drive 1.5 hours to get the new ones, then return.

Jeff

[Edward Buker]

You should be fine not turning the engine battery off for 5 hours but it will not hurt anything if you do. Your procedure is very good. The solar panels will be close to inactive, I would just tape the + cable end off that comes from the panels and tie wrap it temporarily out of the way. A couple of other things, it is a good time if you have a plastic tray below that tends to hold water to drill a couple of 1/2 inch holes in it for drainage. It also is a good time to really clean up the cable ends with a wire brush and neutralize any corrosion with baking soda. Also easier to move and lube the tray mechanism with the batteries not in it, I have gone to a dry slide out spray lube for this. Also check the welds and frame corrosion for a future project if it is getting to be time. I would buy some of this CRC product and spray the terminals when you are done and tie wrap the cables as needed to allow easy access for water filling. Most of the golf cart batteries have slots for that purpose. Hope this helps.

Later Ed

[Carol Moffett]

Keith here
Jeff, you might find it best to have several good photos of the original configuration.  As a referance it can be handy just to be certain all is well in the end.

[Roy Warren Co-Admin]

Jeff,
Not only would I take photos, but I would draw a diagram and then label each cable as I removed it.  I would note on the diagram which cable went to which terminal.  You might have a loose cable or two going from a negative terminal to a positive terminal.  I know how hard those darn cables are to bend thus being able to attach them just as they came off can ease the job.
Roy

[Jeff Watt]

Thanks for the advice. They are AGM batteries so there is next to no corrosion, however I will take the advice and clean/lubricate the slides. As the batteries are in two compartments (don't know why) the wiring is pretty strait forward, nevertheless pictures and tags can't hurt. The pain, somewhat literally, is going to be getting them out - will get a friend to help as the batteries are 4D and weigh about 130lbs each.

I expect It will be a longer process than 5 hours as things have come up (i.e take batteries out one day and install the next) so I may turn the chassis battery switch off or possibly put a small charger on those batteries as the solar won't be doing anything.

Jeff

[Keith Oliver]

Jeff:

I have found it helpful to use a zap strap to consolidate the wires that come off of each of the battery terminals.  Then you can be sure they go back in exactly the same position they came from.

I have turned my chassis batteries off for weeks at a time with no ill effect, so an overnight of disconnect will do no harm.

[Bob Stone]

If you have a battery temperature sensor from your inverter it should be the first cable attached to the battery post, in contact with the battery. Apparently the battery has to get fairly hot before this device comes into play but if mounted on the post above a cable or two the heavy copper cables will act as a very efficient heat sink and the sensor will not get an accurate sense of battery temperature.
Far from being an expert in this area perhaps Ed will comment.

Bob

[Edward Buker]

Bob,

It is probably a good idea to have the sensor be the closest heat sink material to the battery post (first on the stud) if it will fit and still be able to attach the battery cables properly. The sensor is trying to accurately sense battery temperature and taper the charge current if things get too warm.

A couple of other things, you can easily over tighten a battery terminal, remember the stud head is embedded in lead that is quite soft. Just snug it up pretty well and be happy with that. This little handy strap lift is available at any place that sells golf carts and it adds some safety to lifting and carrying batteries...it also helps save your back. They are under $8 usually and work very well. They attach to the same area that you can use for tie wraps to keep the cables neat and out of the way of the watering holes. Jeff not sure if they make a 4D strap but you would think they would.

http://www.ebay.com/itm/like/161315064978?lpid=82

Later Ed

[Paul Bowers]

Agree with making a diagram.  I took photos of the cables before I started replacing my batteries and also a diagram.  I used the photos to hook everything back up and thought everything was right...referred to the diagram and I had missed a positive cable that had fallen back behind the tray.  Should have used the diagram and verified with the photos...

[Jeff Watt]

Just picked up the batteries yesterday afternoon and too many other things going today to put them in - job for tomorrow.

Anyway regarding the temp sensor it is a cable/wire that is taped to the side of the battery using metalic tape.

Secondly, there are two small gauge wires (10 or 12?) on the batteries with a small fuse box. When taking the old batteries out, I thought this must be for the solar panel and isn't it nice the fuse is right here by the batteries (see photo). Then I started wondering, 1) why would the solar be charging the house and not the chassis and (2) pretty small gauge wire for charging.

So my thoughts are they are to do with the Magnum Remote sending it information. Which is ok, but then back to where does the solar come into play. On my coach there is a space between the front battery compartment and the back compartment. In it is where the big switches are mounted and also where there are big blocks in which the two sets of batteries are tied together. There is another set of wires coming into it which I assume must be from the solar controller, but I don't know.

On the chassis battery is a second, slightly lighter gauge (6 or) wire which I believe is for the generator.  I Need to check as I know it used to be on the house batteries - I had posted about that issue a while ago. I think when I had the Generator repaired I have a feeling the tech moved it to the chassis batteries probably just on his own initiative as I asked for it to be done but the service manager didn't want to do so.

Shouldn't be problem putting back in - just heavy beasts but they have built in cable handles.

Jeff
 

[Steve Huber Co-Admin]

Jeff,
Solar panel charges house batteries. Wire size is not large as the current output of the charger is low, similar to a trickle charger.
Steve

[Jeff Watt]

Steve,

According to my manual the solar is supposed to charge both:

The HPV-30D Charge Controller includes the following:
 Dual Battery Bank Charging - The controller automatically sends charge to both the House and Engine batteries at the same time.

Consequently I am not sure if the cable is for the solar or the magnum remote.

Jeff

[Jeff Watt]

UPDATE: the coach is inside, so turning on the overhead fluorescent lights I used my meter and had 2.7v at the fuse box. So I guess you are correct Steve that it is the line from the solar to the house batteries. I was under the assumption that the chassis are also charged, although there is no similar wire going to them. Have to look further.

Begs the question, if there isn't a solar source to the chassis, won't they run down if just siting - I thought that was the primary job of the solar panel, i.e. keep the chassis batteries up.

[Edward Buker]

Jeff,

The solar panels keep the house batteries up if there is little discharge and enough sunlight. If the house batteries achieve about 13.2V from some source of house bank charging and you have an echo charger or equivalent then the two banks will get connected together and share the charging source. If the voltage on the house bank is lower, less than about 13.2V then there is no source of chassis bank charging in most cases given the circuitry in a coupling charger disconnects the two banks. The Big Boy system acts in a similar fashion of you have that option.

Later Ed

[Joel Ashley]

I'm sure Jeff has the Big Boy and BIRD features, Ed, so you're right;  when his house bank hits something north of 13.2v regardless of charging source, the current transfers to jack up the chassis bank.

Joel