Battery Life

GallenH · 03-03-2019, 10:53 PM

This concerns the engine battery, not the cabin battery. Our PW belonged to my father in law and we've owned it for 3-4 years. I remember once visiting him and replacing the battery which makes it at least 5 yrs old; maybe more. So my questions:

Do any of you treat the engine battery similar to tires in that after "x" years you simply replace it? I once knew a single woman who replaced her auto battery every year just to avoid failure. Ok. That's extreme, but she had the money to do it.

I'm assuming that it's possible, in an emergency, to jump your engine battery with your cabin battery? Mine are both group 27s. If so, I would assume that you carry jumper cables long enough to do that.

Any other things you do to prepare for battery failure?

Sorry. I know that it's a pretty basic question but recalling the age of my battery got me thinking...........

Thanks.

g1g · 03-03-2019, 11:39 PM

I keep a batteryminder on mine 24/7 and my batteries last over 10 years. As for anything else I carry a portable power pack jump unit that also has a tire inflater and more. That way i get a little insurance and more.

gregmchugh · 03-03-2019, 11:43 PM

Quote:

Originally Posted by GallenH

This concerns the engine battery, not the cabin battery. Our PW belonged to my father in law and we've owned it for 3-4 years. I remember once visiting him and replacing the battery which makes it at least 5 yrs old; maybe more. So my questions:

Do any of you treat the engine battery similar to tires in that after "x" years you simply replace it? I once knew a single woman who replaced her auto battery every year just to avoid failure. Ok. That's extreme, but she had the money to do it.

I'm assuming that it's possible, in an emergency, to jump your engine battery with your cabin battery? Mine are both group 27s. If so, I would assume that you carry jumper cables long enough to do that.

Any other things you do to prepare for battery failure?

Sorry. I know that it's a pretty basic question but recalling the age of my battery got me thinking...........

Thanks.

You could get it tested regularly to see how well it is performing.

I have the original chassis battery in a 2008 RS Adventurous that seems to be fine. It is possible it was replaced once before we bought it in 2012, I have never looked at the manufacturer date on it to see. So, it is somewhere between 7 and 11 years old at this point. I also carry a jump start lithium battery and jumper cables to connect the house AGM batteries to the chassis so I wouldn’t be stranded if it failed.

booster · 03-03-2019, 11:58 PM

Our driver starting batteries usually last 6-9 years on average, and those take a beating with lots of starts and short drives, so if one in a van is topped off regularly, it could easily last longer than that I think.

In the van, I have a marine starting battery as we use to keep that as reserve power for the compressor frig, but have learned we didn't ever need to use it. If we get a dead starting battery we can easily use the coach batteries to start the van as we have a manually controlled separator.

avanti · 03-04-2019, 12:14 AM

Quote:

Originally Posted by booster

If we get a dead starting battery we can easily use the coach batteries to start the van as we have a manually controlled separator.

When I installed our UHG, I left the separator in place exclusively for this purpose. It is the only remaining connection between the two systems except for the Trik-L-Start. Between these two devices, I am not worried.

JohnnyFry · 03-06-2019, 01:19 AM

I have had with my Chevy chassis phantom parasitic discharge problem draining the battery when the van is not used for some time. Like Booster, I installed a manual separator relay with a switch and indicator light on the dash. If the starting battery is down I can bridge the batteries and boost the battery. The wiring from the house batteries is too small to allow it to crank the engine but switching and allowing a 10 minute wait to charge usually does the job. Another benefit, it allows for charging the chassis battery when connected to shore power or running the genie.

GallenH · 03-06-2019, 04:54 AM

Thanks to all. I think that I'm going to wait on replacing the engine battery and invest in a 20' set of jumper cables. Any recommendation for brand? I've looked at a few on the market and they appear to be copper plated aluminum and not solid copper. I read somewhere that there is a 40% loss of power with the former compared to the latter. Don't know if that's true. But, if so, it would appear that pure copper is better. I saw one set that was advertised as pure copper and selling at c.$100 but some reviewers said that it wasn't. So pure copper seems pricey. When you start getting into that range, you're not far from the price of the lithium jump units for sale.

Doneworking · 03-06-2019, 01:43 PM

I carry an ancient set of jumper cables that are actually copper and will reach from the coach batteries to the chassis battery. I don't know how old they are but they belonged to my dad and he as been gone for sixteen years. It is not something that wears out.

I replace the starter battery in all our vehicles every five years. I buy all my batteries at Walmart or Sams and they have given me good service for a long time. I simply don't want to be out in the boondocks and have battery problems or hassle and I just consider the replacements as regular maintenance and insurance.

avanti · 03-06-2019, 02:00 PM

Quote:

Originally Posted by GallenH

I read somewhere that there is a 40% loss of power with the former compared to the latter.

Here are the facts:
--Aluminum has 61% the conductivity of copper. So, in this sense your 40% figure is more-or-less correct.
--BUT aluminum weighs only 30% as much as copper.

So, if the aluminum jumper cables are the same gauge as the copper ones, they will indeed lave a significantly lower ampacity (Although this is not the same thing as saying that you will lose 40% of the power--that depends on other factors).

However, it is quite possible to chose a gauge of aluminum that has exactly the same ampacity as a given gauge of copper. If you do this: (a) it will be MUCH cheaper, and (b) it will weight only half as much as the copper wires. It will just be bulkier.

markopolo · 03-06-2019, 02:04 PM

A short jumper cable could be used to connect the house and chassis battery via the house battery connection under the hood at the isolator to boost the chassis battery if an emergency start is needed.

I'd first used it to charge the chassis battery a bit then disconnect it & try to start the van because the fusing and wiring on the house battery side isn't designed to handle the full current needed to start a van.

Most motorhomes that I've owned had a way to boost the chassis battery by using a switch. The Roadtrek I had years ago was the exception and lacked that useful feature so I carried a short jumper just for the (+) side to use as a manual boost connection.

browngw · 03-10-2019, 07:28 PM

The Lithium Ion battery jumper/USB power supplies are so useful and relatively inexpensive ( and compact for storage) that jumpers are bulky and not required. I started my Ram 5.2L V8 Pleasure-Way easily with it and now carry it in my new Promaster Carado. I think mine is a NOCO 1000A model.

booster · 03-11-2019, 01:33 AM

Quote:

Originally Posted by Deano

As both the chassis and coach batteries are grounded, if you need to jump, you only need to connect the positive posts. You can use a set of 10 footers connected end to end if you only need 20' total.

I think you would need to look at the size of the engine block to chassis cable before doing that, as the battery ground often goes the block so less resistance for the starter, and then there is flex ground (braided often) underneath from the block to the chassis. That ground to the chassis is sometimes quite small depending on how much power any given chassis might use. Other times there may be no block to chassis ground but there will be a second wire coming out of the battery cable going to the chassis which also can be very small for starting. I have seen them as small a #8 wire.

Deano · 03-11-2019, 01:42 AM

Thanks Booster,
You make some very good points as always.
I deleted my post and sit corrected.

booster · 03-11-2019, 01:46 AM

I think it does bring up an interesting idea for saving some space, though. The coach ground will be full size so no issue, and the chassis is fine, so the starting battery negative jumper cable could be short and just go to the chassis someplace in the engine compartment of subframe.

avanti · 03-11-2019, 02:02 AM

The idea is definitely worth considering, as is Booster's warning. A couple of thoughts:
1) It is usually not that hard to upgrade the engine ground.
2) If you are using the coach batter simply to boost a weak starting battery, the current is often not that huge.
3) There is always the option to simply connect the two batteries a while to charge up the chassis battery, rather than trying to start the vehicle during the jump. Lots of people who have "boost" switches use them this way, despite sub-par wiring.

booster · 03-11-2019, 02:12 AM

Yep, upgrading the ground wiring is not a bad job even as DIY. The audio and street rod types have lots of cables for just that. We use a stainless steel braided 2*/0 equivalent for our engine generator setup.

Does anyone know if Roadtrek upgrades the engine to chassis ground in the engine generator setups?

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