12v HOUSE BATTERIES WIRED WRONG

[Dr4Film]

Walk no RUN away from this deal as fast as you can!

Just as a reference, I was in Karen's RV shop in Anchorage Alaska this past fall waiting on my coach to get serviced when this older gentleman came in to pick up his coach. I overheard some of the conversation from the waiting room and spoke with the counter tech once he left. From what he said the guy had hooked up a new set of four 6 VDC House Batteries incorrectly and fried a bunch of stuff. One big expensive item was the Inverter.

He had that replaced under EXT Warranty at the shop but he also said that the generator no longer starts along with a whole bunch of other stuff no longer works correctly in the coach.

The shop wasn't asked to work on anything except to replace the Inverter under warranty.

Who knows how much damage he did to his coach with a simple mistake of hooking up the batteries incorrectly.

Bottom-line, your situation is even worse so I cannot even imagine how much stuff would have been compromised inside and outside of your coach.

Control boards are expensive!

Two very expensive items are the ECM for the engine and transmission. Hopefully they are powered from the Chassis battery.

Dr4Film ----- Richard

[powercat_ras]

Have to guess he really put 12V batteries where 6V ones were and got 24V not 72V. That said, its still bad.

The 12 volt wiring in the coach should be fine as there are fuses that are sized to protect circuit wiring.

Anything that had a power switch in series, like power awning motors, lights, and exhaust fans, that never had the power switch turned on should be undamaged.

Things that over-voltage could have damaged (they don't have on/off switches)

- refrigerator control board
- furnace control board
- gas water heater control board
- propane gas detector
- slideout control boards
- 12 volt power converter
- 12 volt TVs
- 12 volt entertainment
- 12 volt roof-top sat control box, if equipped

IMO the worst case hardware cost to fix this would be less than $ 1,500 unless the slideout control boards are really pricey, plus labor if you can't DIY. Worst case under $ 5,000 with RV dealer over $ 100 per hour labor rates. If he takes to a dealer and shows your the work report on what was found and repaired and the bill and it makes sense with the above then I think you would be OK. You might still might ask him to drop the price a bit for insurance so if the dealer missed something that you find wrong later you will have some funds.

[Hooligan]

Originally Posted by FIRE UP

72 volts into the coach

I am by far, no electrical wizard here. But, if you hook 6V golf cart batteries up in parallel, you get 6V. If you hook them up in series, you get 12V. Now, if you hook up 12V batteries in parallel you get 12V, correct? And, if you hook them up in series, don't you get 24V and not 72V?
Scott

Normally the six 6volt batteries would be 3 parallel banks of 2 batteries, connected in series. Adding amperage of each bank and giving 12 volts. The same configuration with 12 volt batteries would give 24 volts at 3 times the amperage. Not 72 volts. Of course, still not a good thing.

A good tech should be able to locate initial damage and an agreement with the owner for a "warranty" for later problems related to the electrical snafu.

(powercat just said the same thing)

[twinboat]

Originally Posted by FIRE UP

72 volts into the coach

I am by far, no electrical wizard here. But, if you hook 6V golf cart batteries up in parallel, you get 6V. If you hook them up in series, you get 12V. Now, if you hook up 12V batteries in parallel you get 12V, correct? And, if you hook them up in series, don't you get 24V and not 72V
Scott

In your example above, that is true with 2 batteries.

If you hook up 6, 6 volt batteries in series, you get 36 volts. Golf cars run on 36 volts.

6, 12 volt batteries in series adds up to 72 volts.

[8Birds]

Thanks, guys. There were 6-12v bats in series. Doesn't that make 72v? There are solenoids, relays, inline fuses and more tha are my worry, not to mention the bus jockeys along the road with hands out waiting for breakdowns like me. I sadly passed on this coach.

[computerguy]

You'll sleep better at night. Don't fear there are many many good used coaches out there. You will find one you like. Take your time to get the right one. Keeping looking

[jmcannonball]

Good for you. I would have made the same decision. Too many other coaches out there just waiting for you!

[mel s]

Originally Posted by 8Birds

Help please, guys. Buying a 2002 Beaver 42. Owner to deliver March 18-20. Owner called today saying that he installed and switched on 6 new 12v batteries (instead of 6v deep cycle batteries) that put 72 volts into the coach.

Originally Posted by FIRE UP

72 volts into the coach

I am by far, no electrical wizard here. But, if you hook 6V golf cart batteries up in parallel, you get 6V. If you hook them up in series, you get 12V. Now, if you hook up 12V batteries in parallel you get 12V, correct? And, if you hook them up in series, don't you get 24V and not 72V?
Now, again, no electrical genius here but, usually, if something is drawing more than a circuit can supply, that's what a fuse is for, correct? But, what about if TOO MUCH voltage is BEING SUPPLIED? Won't the fuse blow in that situation?
Scott

FIRE UP
Apparently you misread 8Birds post?
He said the owner "installed and switched on 6 new 12v batteries".
(6 12V batteries when hooked up in series equals 72 volts).

BTW, fuses blow if/when the AMP DRAW is greater than their rated capacity... (NOT if/when the VOLTAGE is to great).

Mel
'96 Safari

[Dr4Film]

Help please, Owner called today saying that he installed and switched on 6 new 12VDC batteries (instead of 6v deep cycle batteries) that put 72 volts into the coach. Said the interior lights blew as soon as he switched them on. Turned battery disconnect off. Now slides don't work. Says some other electrical stuff not working. Has coach into coach service center to check out the electrical. I need member opinions ASAP.

By the way, what was this guy thinking when he did that? CRS!!!

When working on any battery bank ALWAYS take a photo PLUS make a schematic drawing on paper BEFORE touching any of the cables or connections.

Now down the road when he goes to resell the coach, some sucker looking for a 2002 Beaver will be stuck with his mistake. I doubt that everything will be addressed in the coach that got affected.

Dr4Film

[mojoracing]

Originally Posted by powercat_ras

Have to guess he really put 12V batteries where 6V ones were and got 24V not 72V. That said, its still bad.

The 12 volt wiring in the coach should be fine as there are fuses that are sized to protect circuit wiring.

Anything that had a power switch in series, like power awning motors, lights, and exhaust fans, that never had the power switch turned on should be undamaged.

Things that over-voltage could have damaged (they don't have on/off switches)

- refrigerator control board
- furnace control board
- gas water heater control board
- propane gas detector
- slideout control boards
- 12 volt power converter
- 12 volt TVs
- 12 volt entertainment
- 12 volt roof-top sat control box, if equipped

IMO the worst case hardware cost to fix this would be less than $ 1,500 unless the slideout control boards are really pricey, plus labor if you can't DIY. Worst case under $ 5,000 with RV dealer over $ 100 per hour labor rates. If he takes to a dealer and shows your the work report on what was found and repaired and the bill and it makes sense with the above then I think you would be OK. You might still might ask him to drop the price a bit for insurance so if the dealer missed something that you find wrong later you will have some funds.

Powercat is right on the money! I would not give it a second thought if everything was working correctly and unit has been gone through by a competent repair facility. The few things powercat mentioned should be about it. Much less work and issues than everyone is making it out to be. Just make sure everything is working to your satisfaction. I say go for it!

[computerguy]

Originally Posted by mel s

FIRE UP
Apparently you misread 8Birds post?
He said the owner "installed and switched on 6 new 12v batteries".
(6 12V batteries when hooked up in series equals 72 volts).

BTW, fuses blow if/when the AMP DRAW is greater than their rated capacity... (NOT if/when the VOLTAGE is to great).

Mel
'96 Safari

Good point. To try and clarify the 6V discussion, you can hook the batteries up both in parallel and in series. So in a case where a coach has 4 6V batteries you will have 2 batteries hooked up together to make 12V and another hooked up together to make 12V. Then the 2 sets are hooked up to increase the amp hours and leaves the voltage at 12. Clear as mud, I know.
Whenever I take my batteries out I always take a picture of the wiring first. I am no electrical expert so better be safe than sorry, as the topic of this thread shows...

[HHIDan]

No one will ever know how the batteries were really wired. With the cables available and going from 6 to 12, my bet is this coach ended up seeing 24...
You hook up as many pairs of 6ers in series you get 12...
You hook up as many pairs of 12s you get 24...
Still the point was too many volts... quickly leads to overcurrent... quickly blows fuses.

Totally agree, whoever wired these batteries should stay away from anything electric!! I will go so far as to say if you need pics to re-wire your batteries, stay away. Or wear good glasses, ear protection and a helmet!!!

[mel s]

Originally Posted by HHIDan

No one will ever know how the batteries were really wired. With the cables available and going from 6 to 12, my bet is this coach ended up seeing 24...
You hook up as many pairs of 6ers in series you get 12...
You hook up as many pairs of 12s you get 24...
Still the point was too many volts... quickly leads to overcurrent... quickly blows fuses.

Totally agree, whoever wired these batteries should stay away from anything electric!! I will go so far as to say if you need pics to re-wire your batteries, stay away. Or wear good glasses, ear protection and a helmet!!!

HHIDan
Over voltage will not necessarily blow a fuse...(however anything that draws more amps than the AMP rating of a fuse will blow that fuse)

8Birds
If someone had put to many volts into to the 12 volt system of your coach you would have 3 choices, (fix everything that was damaged, have it fixed, or sell the coach).

However since you have not yet bought the 2002 Beaver that the owner/seller put enough volts into to blow the interior lights, (and who knows what else), you have a 4th choice... simply do not buy it...(which is the common sense choice many have recommended).

It's your choice to make, (if you choose wisely methinks you will be satisfied with that choice).

Mel
'96 Safari

[bobmac]

Applying 6 times the rated voltage to anything electrical will - at the least - dramatically shorten the life expectation - if it didn't destroy it then. You could experience failures that don't show up initially. Run away from the deal.