Time for chassis batteries?

[neilnoff]

I've read tons of chassis battery threads on the forum and if I do need new ones, know what I will buy. Question is: Is it time? I've noticed that the past several times I've started up, the engine is slow to turnover and if it was my car, I'd be thinking "Bad battery." I keep the coach plugged in to 50amp and the panel shows 12.4v. Previously it usually read 12.9v (I think). We bought the rig in Oct 2019 and assuming it was on the lot for a few months, not plugged in, and it was likely built in spring of 2019 (?), those batteries are coming up on 4 years if not older & have been in Houston heat in the summer. Would you replace yours in this situation? Frankly, I'd rather lose a year that I may be able to squeeze out them than have to worry each time I start if she's going to fire up -- maybe I just answered my own question?

Thanks in advance and happy 2023 to everyone!

[Gary.Jones]

Your batteries are likely Relion batteries. My personal experience is that you have gotten more life out of them than many. My experience with standard house batteries from Middleberry are that they are not high quality. AND, your assumptions about your coach prior to purchase are probably correct.

Of course, you can have them load tested. I would probable replace them with something much better.

Gary

[brobox]

I have already replace the chassis batteries in my 21. One was bad on delivery the second one leaking and bad within a year.
I am a big fan of group 31 professionals sold at Sams' under the label of Duracell. They are made by East Penn, on of the top manufacures in the USA, and about a $80 savings at Sam's. Also Sam's as a nationwide carry in warranty.
My House batteries only made it 20 months before they would no longer hold a 2 hour charge. I have replace all of the batteries in my 21 already.

[gpounder]

Is it real cold?


IF so a lead acid battery performs poorly. Basically a starting battery is overbuilt for the actual need. This over built part dwindles as the battery ages and when real cold the over built portion gets even smaller.

Lead acid batteries need to be reinvigorated form time to time to maximize life. Technically it is called equalization. That is a high voltage high current charge for an hour or two. It causes the electrolyte to mix and excites the cells more than usual. It also brings the battery to a real full charge. Look up equalization and see if you can do that. You may be surprised the battery will work better.

[YC1]

Other things aside such as the cold, we only rent batteries. So it is time. Now or later when you can't get to the sale or to the ones you really want.

However, the voltage you are referencing says they are not getting charged. You should have the same voltage on the engine batteries as your house batteries if the BIRD system is working. Shoreline charging is showing 12.9 on your house batteris which is fully charge. The 12.4 on the engine batteries is basically run down. There are charts to show you that.

Prop your boost button or have someone hold it down while you check the voltage on the engine batteries. See if the voltage is climbing or where it started.

I do not know your layout but someone here does. If you post some pictures of your battery compartment and wiring we should be able to guide you.

To be clear, you are not shutting off battery switches, Except any house switches?

[Nowabeachbum]

I replaced mine 3 months ago on my 19. Chances are you’ve gotten all you’re going to get out of them. Like Chuck, I went for Duracell.

[Alpine36]

When in doubt, change them out.
Low capacity or failing chassis batteries have been known to wreak havoc on starters/solenoids/alternators. Just not worth the risk IMHO.
I second the Duracell (E.Penn) brand. Solid performers reasonably priced.

[brobox]

Originally Posted by Alpine36

When in doubt, change them out.
Low capacity or failing chassis batteries have been known to wreak havoc on starters/solenoids/alternators. Just not worth the risk IMHO.
I second the Duracell (E.Penn) brand. Solid performers reasonably priced.

Nice to see someone that recognizes what damage is being done trying charge batteries that will no longer hold a charge. So many think it will be fine after I plug in tonight, but don't realize the damage being done to the alternator driving with bad batteries.

[twinboat]

Change them if they test bad, not due to a feeling.

After that you'll probably have the same situation, low chassis batteries from parasitic loads.

If your bi-directional charging system is funtioning,, house and chassis batteries should be close to the same.

It could be a bad isolation solenoid, very common, or it could be your battery temp sensor plugged into the inverter/charger. When they go bad, it will effect the charging voltage which effects the isolation solenoid.

The isolation system needs 13.2 volts to connect the house batteries to the chassis batteries.

[gpounder]

Originally Posted by brobox

Nice to see someone that recognizes what damage is being done trying charge batteries that will no longer hold a charge. So many think it will be fine after I plug in tonight, but don't realize the damage being done to the alternator driving with bad batteries.

A battery that is worn out - lost capacity does NOT damage a alternator. In fact they charge up and draw very little current when fully charged. It is for this reason your voltmeter on the RV shows the battery as charged because the voltage looks normal.

A old battery can no longer exchange electrons to store or provide the power it was capable when new.

But a starter that turns very slowly can be damaged. It is for that reason I will hold the boost switch down to add the house battery when staring a very cold engine. Just know the boost circuit is not made as a substitute for a chassis battery as most have a fuse or breaker, mine is 200 amps.

[RVFunlovers]

Spartan changed both chassis batteries on my 22 last November.

Both tested bad on the load test.

To their credit they changed both under warranty.

Maybe these batteries are low end and take a beating by not being charged from the time they leave Spartan to the coach is done.

My 17 coach was on the original chassis batteries when we sold the coach in Sept 2021 and they were still working good.

[MRUSA14]

Loose or dirty electrical connections will often give the same symptoms as a bad battery. This should be something you check carefully before any battery replacement. The OEM chassis batteries in my 2013 Anthem lasted more than 8 years.

[brobox]

Originally Posted by MRUSA14

Loose or dirty electrical connections will often give the same symptoms as a bad battery. This should be something you check carefully before any battery replacement. The OEM chassis batteries in my 2013 Anthem lasted more than 8 years.

Mark, totally agree the batteries that Spartan was using in the Classics were much better. Mine were 5 years old when I sold the 14. The 19 never did spin the engine like the 14 did, but I figured it was the same batteries trying to spin a 605 HP that were used on the smaller engines and short on amps.

The 21 was delivered to NIRVC, upon inspection one battery was leaking and gassing so bad it had corroded the metal tie down strap. Only the bad battery was allowed to be replaced under warranty. Withing a year, as pictured above the second batter was leaking and corroded. Spartan has definitely changed the quality of the batteries in the newer coaches. I think the Harris is one step below the Discovery batteries, from experience that is pretty low.

I see NowaBeachbum did much better than I did with his batteries. I guess it is luck of the draw. You are still correct on checking and cleaning the cables

[neilnoff]

Thanks to all of you for the responses & suggestions & they make sense. Confirmed my original thoughts and looks like a trip to Sam's is in my near future. I assume you all went with the Duracell 31C, with 950 cca? We are heading out next month for 6 weeks, and then leave in late May for a 6 month trip, so peace of mind is worth a few $$.

Thanks again & safe travels all--