Community Forums

bluegrassrv · 04-29-2014, 02:33 AM

The DW and I have been in the market for a used DP for several months now. I'm thinking that getting load tests done on all the batteries of a prospective coach (not one we're just looking at, but one we're about to lay out some cash for), would be a good idea. At what percentage of CCA should I say they are to far gone and need to be replaced?

RV Wizard · 04-29-2014, 02:45 AM

As long as you have the more serious components and systems covered already the cranking batteries should be above 90%. The house batteries will have to be at least 70% if you never boondock and I would negotiate on anything less.

TQ60 · 04-29-2014, 09:03 AM

Batteries are a consumable item just like tires.

Simply insist they be replaced as part of the deal...but your choice.

Seller will not place best and you want best.

Determine what you woukd install and that cost.

Then use as leverage.

Testing only finds bad batteries...testing for good batteries requires full charge and timed discharge and few folks know how or are equiped to properly test them.

A short load test or impeadance test does not indicate a battery is good.

They can indicate a bad battery and also indicate not bad but not bad does not mean that it is good.

This makes no sense...

But a good battery needs to hold a load for say 2 hours and using a higher load for 10 seconds is not the same.

If instead of 2 hours it only lasted 1 hour it would be at 50% so it is not good.

However if it is still working it is not bad so to speak.

And it will still pass the 10 second load test just fine.

So assume if they are 2 years old the will need to be replaced as part of the deal.

dennis45 · 04-29-2014, 09:16 AM

You can replace 2 chassis and 4 house batteries for under $800. Batteries would be the least of my concerns as long as they are working.
There are more expensive components to worry about such as age and condition of tires, engine/Trans condition. Fluid samples would be in order for engine/Trans.
What about steering/suspension? How are the brakes?
Roof condition. Is there or has there been any leaks?
Any one of these can hit you for 3-4K or more.
IMHO, batteries are pocket change compared to the big ticket items.

vsheetz · 04-29-2014, 10:16 AM

Agree with others that batteries are a consideration, nut not a huge one. They are a consumable. Newer is a plus, older is not a big deal.

Dutch Star Don · 04-29-2014, 09:19 PM

In my case.....if I was selling a coach and you asked to disconnect all of my batteries and test them, I would agree once you paid the purchase price, signed the AS IS paperwork and drove away. Bad things happen when people start disconnecting batteries....often the bad things cost thousands of dollars to fix.

bluegrassrv · 04-29-2014, 11:05 PM

RV Wizard & TQ60, thanks for a straight answer.

RV Wizard · 04-30-2014, 02:37 AM

Quote:

Originally Posted by bluegrassrv

RV Wizard & TQ60, thanks for a straight answer.

You are welcome.

Ray,IN · 04-30-2014, 05:36 PM

TQ60/Tony is right, load-testing requires correctly-sized equipment- to battery size, and a skilled operator, otherwise load-testing is useless. I would suggest an alternative means, specific-gravity testing, not as accurate but sufficient. Here again the operator must know how, when to test, and how to interpret the readings. This may be performed with batteries in-place.

TQ60 · 04-30-2014, 06:57 PM

Specific gravity only indicates state of charge and not much else by itself.

Reading all cells it can indicate the odd man out though.

Best is to just do visual and maybe just check the voltage in an "I know wjat I am doing" mode and unless the are new assume you will replace them soon and use that as leverage.

Other things like hvac that can be bigger issue.