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Custom Battery Cables for motorhome

Yahoo Message Number: 66506
FYI

Wish I had found this place sooner. I recently spent over $250 dollars cutting and crimping some new battery cables at West Marine to add two more house batteries in my coach. What I ended up with is 3/0 gauge cable (the largest gauge they had). I wanted marine grade cable because of the extra tinting on the copper wires and flexible cable like welding wire). I had to crimp and shrink wrap them myself for the first time and they came out ok but it was not a die crimper that compresses the whole lug around the wire. I am running a total of 980amp hours with 4 AGM 8D house batteries.
Since West Marine did not have 4/0 cable I had to double up a 3/0 cable for the additional shunt to negative terminal on the inverter. All the other suppliers of 4/0 welding cable I could find sold the wire in bulk and the shipping was way out there.
A couple days ago I found this business on the internet that does all of this work for 1/3 of the cost and the crimps (die crimped) are far better than mine or the original ones on the country coach (stamped). The 4/0 cable was the same quality as the West marine 3/0 cable but at 1/3 the cost and the lugs where 1/3 the cost and excellent quality and bigger ends. The shrink wrap was liberal and the very thick adhesive type.
Never met the guy or talked to him. He processed my order in less than 12 hours and had the order in the mail the next day. I ordered a single 4/0 1 foot crimped cable to replace the (2) 3/0 cables, late Saturday night. I just got my order in the mail today . Great service with personal emails keeping me up to date with the order and shipping.
His name is Gregory M. Lawrence and his business is Greg's Marine Wire Supply. Located in Auburn WA and his internet site is gregsmarinewiresupply.com
I might replace the wires in my boston whaler and few more cables in the County Coach because some of them are much longer than they need to be and this place makes it very affordable to do this. His web site allows you custom order the length and various sizes of crimped lug ends.
I am thinking I could have him make me some really heavy duty custom jumper cables for a lot less money than buying the thinner 4 gauge jumper cable. I had to help a guy jump start his 40 foot Class A Diesel this past weekend with my coach and it took a half hour to charge his battery enough with my jumper cables to get it to crank in 25 degree weather after we nearly toasted my cables trying to do a quick jump start. His house batteries were no good.
I wish I had known about this business sooner. All the other custom cable cutters I have found were just as expensive as Theft Marine or would take their time putting together custom orders.

Dallas 2004 intrigue ovation C12 11688

Re: Custom Battery Cables for motorhome

Reply #1 –
Yahoo Message Number: 66507
Thanks for the info Dallas. I book marked it.

Larry 03 Allure 30856

Re: Battery matching and aging

Reply #3 –
Yahoo Message Number: 66514
We all know that one shouldn't mix battery types in the same bank and that it's desirable to have all batteries in a bank approximately the same age.
Is it necessary or just desirable to have the same type batteries in the coach starting bank and house deep cycle bank? The question arose recently while talking to a Lifetime dealer about the apparent lack of a Lifetime AGM start battery in the D8 size. He said to simply install a lead acid type with suitable cold cranking capacity as the start battery. I actually visited them to see what their shop capability was and was turned off by their inability to offer installation although they would be glad to order Lifeline AGM batteries at $650 a pop plus $100 shipping for the first one and reduced shipping charge for the 2nd. Since the main reason for going the AGM route is to get away from battery electrolyte maintenance there doesn't seem to be much reason to change if you've got to maintain a regular lead acid start battery and my own personal opinion is that an outfit that sells this stuff should have shop capability for installation and preferably actually have the product in stock.
Is it important or just desirable to have the batteries in different banks the same age? My batteries are coming up on 4 years old and I think my start battery is going bad. I need to decide whether to replace just the start battery or the tow deep cycle house batteries too. What kind of battery life are you guys getting before changing? My first set went to five years before changing and my old converted bus even longer.

Jim M

'02 Intrigue #11410, ISL 400

Re: Battery matching and aging

Reply #4 –
Yahoo Message Number: 66515
You have two battery banks, coach/house and starting. You can replace the starting without having to replace the coach. You want all batteries in a bank to be the same. No problem with treating each bank separate. You do not have to replace with a 8D, you can use more of a smaller battery just as long as you get the same are more cranking power. You can use smaller sealed batteries if you want. Seems I have seen sealed 8D's. Might do more checking at other suppliers. Interstate makes good batteries as well. I would be careful not having batteries rated for starting, some are rated for starting and deep cycle. Those maybe alright for smaller vehicles. Would have to do lots of research before I would want to use them to start a big diesel. But you do have options.

Leonard K.
97' Magna 5418

Re: Battery matching and aging

Reply #5 –
Yahoo Message Number: 66518
Leonard,

I believe that they are all in the same bank when you are traveling down the road.

Don Seager

2004 Allure 31046

Re: Battery matching and aging

Reply #6 –
Yahoo Message Number: 66519
That doesn't make a difference in my book. Charging is not the issue as when you start out the banks will not be close to the same charge, most of the time. If dry camping the house batteries will be a lot lower then the starting. They will self level as you drive, i.e. the coach bank will take much more to come up while the starting bank will take a very little. It is the working or load were one bad cell will bring down the whole bank. You want all cells in a bank working together, otherwise the one bad cell brings down that bank, weak link in a chain. The switch on the dash that ties the banks together is to allow the strong bank to "boost" the weak bank.

Leonard

97' Magna 5418

Re: Battery matching and aging

Reply #7 –
Yahoo Message Number: 66520
That is correct. The two banks, coach/start and House/deep cycle are connect via a solenoid switch (200A?) located in the same compartment as the inverter - in my coach the compartment just above the batteries in the battery compartment. This solenoid is activated by an oil pressure switch automatically when the engine is started or by the "Battery Boost" switch on the coach control panels.

In effect, therefore, you could be mixing battery types and ages anytime the main engine is running. They are being charged by the alternator unless the generator set is running in which case the inverter/charger is the DC source also. Whether this is detrimental and to be avoided or not I don't know and is part of the reason for starting this thread.

Jim M

'02 Intrigue #11410 ISL 400

Re: Battery matching and aging

Reply #8 –
Yahoo Message Number: 66523
And if you have a bad cell, general what fails is one cell in a battery, the one cell will not come up to full charge, it refuses the charge. Then when a load is called for the whole bank is down because the one cell will not produce. Changing only offers the current to the batteries, they have to take it. This is why charging the two banks together is not an issue. A cell has a life span of so many charge/discharge cycles. When one cell goes bad, it indicates all the cells tied together under load/cycle times are reaching the end of there life. The house battery will reach their end long before the start batteries, most times, simple do the cycles used.

Way back when, we had a local battery shop that made batteries on site. They would replace just the bad cells, until history told them it was a waste of time and money.

Age is only one indicator of battery life. Cycles and proper care, water, keep charged etc, is the real indicator. If lead acid each cell can be tested two ways, hydrometer and good voltmeter. If they are close to each other the bank is still good, i.e, has more cycles left in their life. A test for all batteries is a load test. If they can carry the required load they still have life. Suggest do not replace a bank simple based on age without complete test. Problems re-charging or carrying a load indicates end of life.

In my book, it is a huge waste of money to replace all batteries under most conditions. One excepting would be buying a used coach with no history on it and all batteries of great age. Even then I would charge and test them first and if they are bad, then would most likely replace all banks for peace of mind. Sitting and self-discharge is deadly to batteries, and they all self-discharge. Good case for battery tenders in storage of any and all batteries.

Leonard

97' Magna 5418

Re: Battery matching and aging

Reply #9 –
Yahoo Message Number: 66525
In Leonard Kerns contribution to this thread he mentions the desirability of the use of "battery tenders " while coach is in storage. How does this relate to being stored on shore power with the charger function of the inverter charging. This eventually settles to a 'float charge" and, if functioning correctly, the "echo charger" that most of our coaches have should be closely following with only a slight loss in relative voltage. Is this adequate or should the shore power be disconnected and/or the inverter/charger be disabled (by tripping it's circuit breaker) and then a "battery tender" installed - presumably one for each bank?

In other words is the inverter/charger + the echo charger equivalent to a "battery minder" while stored under shore power?

Jim M

'02Intrigue#311410 ISL 400

"Good case for battery tenders in storage of any and all batteries."

Re: Battery matching and aging

Reply #10 –
Yahoo Message Number: 66527
I don't think there is any problem having different types/ages. In fact I would guess that 99% of coaches aren't matched.

Re: Battery matching and aging

Reply #11 –
Yahoo Message Number: 66531
Jim, it is neither necessary nor even desirable to match battery type or age across house and start batteries. there is no benefit to matching nor detriment to unmatched.

George in Birmingham
'04 Allure 31038
George in Birmingham
2003 Magna 6298

Re: Battery matching and aging

Reply #12 –
Yahoo Message Number: 66533
Jim,

Your charger and echo will take care of the batteries if the coach is plugged in. Some do not leave there plugged in in storage.

Leonard K

97' Magna 5418

Re: Battery matching and aging

Reply #13 –
Yahoo Message Number: 66534
Richard Not sure where you got your info regarding your statement that size and age do not matter. It is absolutely necessary to match size , age and like batteries. Any good battery shop will tell you that. Think about 2 batteries , one double the size of the other, getting the same charge. The smaller battery will be charged before the larger battery and then will be overcharged , depending where the charging sensing is. The same can be said about age, and batteries that are alike. An old battery can not absorb all the charge as some of the material in the battery is no longer there. Therefore the same problem. ALL battery in a bank should be alike, approximate same age within a year or so, and same size. If you don't you will shorten the life of the whole bank. If you want the longest life out of your battery bank , you would want them all to be the same

Ron Baran 09 Magna 7025

Re: Battery matching and aging

Reply #14 –
Yahoo Message Number: 66535
Non the less Leonard, I believe that my statement as presented is true. The problem is not when charging but rather as the batteries reach full charge while driving down the road. In my coach I have a lead acid coach battery and two AGM house batteries. The voltage, thus the rate of charge, is controlled by the altenator voltage regulator when the house and chassis batteries are tied together. In my case is the voltage regulation correct for both types of batteries? If not then what is the consequence of that? Well it can't be too bad as mine are now 7 years old and going strong, knock on wood.
The problem with paralleling two good batteries of different age has little or nothing to do with bad cells in either one of them. As batteries age and wear their ability to hold a charge slowly decreases. When you parallel an older battery with a new battery, the older battery will become parasitic to the new battery. The net result you now basically have two batteries tied together with sum of the two no better than twice the older one.

Don Seager

2004 Allure 31046

Re: Battery matching and aging

Reply #15 –
Yahoo Message Number: 66536
Is there a reason not to leave the shore power plugged in while in storage assuming one periodically checks the battery electrolyte levels? We store our coach inside.

Jim M

'02 Intrigue, #11420 ISL 400

Re: Battery matching and aging

Reply #16 –
Yahoo Message Number: 66537
I would think it would be more like the average of the two batteries (of significantly different age). Don't really know though. There's probably some complicated formula to calculate it, however.

I would think that a bad cell(s) in either would be very significant because that certainly effects the battery's capacity and its balance relative to the other battery (ies) in the bank.

Interesting to note the different viewpoints of what is generally considered common knowledge.

Jim M

'02 Intrigue#11410 ISL400

Re: Battery matching and aging

Reply #17 –
Yahoo Message Number: 66539
This is only true when no charge is present. So going down the road, each bank is being charged but they do not have to be the same. The regulator will put out full charge until it sees 14.8 volts then it cuts back to 13.2. Once the charge voltage is removed then the current starts to seek it's own level, then what you say occurs, water seeking its own level so to speak. If one has a bad battery in a bank it will keep the others from reaching full charge in that bank. Then the sets or banks are again isolated from each other when the engine shuts off and charge current removed. But the batteries in each back are hard wired to each other and influence each other.

The way they are wired on mine is with a large blue box back by the battery compartment. The starter batteries are the first bank the engine charge systems sees and are hard wired so to speak. The house bank is after this blue box that controls the charge to the house batteries. Battery isolator is the name I believe. It comes on line by solenoid or charge current. Remove or disconnect it and the house bank will not charge from the engine. Depends on how the isolator is designed at what voltage it starts to feed current through it to the house bank. It seems that the isolator will be sure the starter bank is up to a certain voltage before it starts to pass charge current to the house bank. Have not dug into the spec's of the unit, so this is working with other isolators.

Leonard

97' Magna 5418

Re: Battery matching and aging

Reply #18 –
Yahoo Message Number: 66541
The Chassis (starter) battery should be something with a high capacity amperage to unload a lot of amps at one time (thicker gauge battery cables) to start a cold engine. These batteries tend to have thinner plates and more of them in the battery (a lot of electrons moving around) but they are very prone to short lifes if discharged more than 10% (not good for house batteries).
The Deep Cell Batteries (house) batteries are ment for deep cycle charging down to 50% or less. The plates are thicker and they take longer to basically erode under the stress of deep cycle discharges and recharges (not so busy electrons).
You can use a deep cycle battery to start an engine if the starting amps are high enough, but it is a waste of money to use starter batteries as house batteries.
If you charge mismatched batteries (age and type but all 12 volt) all together you will eventually come to some voltage that floats them all and the amperage will tail off. The voltage will stabilize with the lowest voltage battery until it sucks up enough amps to raise it's voltage to the rest of the batteries.
But as has been said in many ways, some batteries will draw much more amperage while on the way to the float. If there is a dead cell then you might not reach a float charge because the voltage is being drawn down by the bad battery. Hence forth keeping all the batteries in good condition north of 12 volts and minimizing the sulfation and low water levels is what matters.
A good battery just feeds a bad battery. They eventaully all go bad because the plates go bad. Some battery chargers have a high frequency pulse which reduces the sulfating. I have been using a batteryminder charger on my Wave runners and motorcycle batteries for years and usually get twice the live out of them. I have been able to rejuvenate what seemed be cronically under powered batteries with these high frequency pulse chargers, especially the deep cycle batteries to full charge and amperage.
I personally would keep batteries within a bank the same amperage and type of battery. I choose AGM house batteries not because I think they will be more cost effective than flooded batteries (they are not IMHO) but because I invested in a very expensive pure sine wave inverter and do not want the battery fumes from the flooded batteries shortening the life of the inverter that resides in the same cramped bay, nor do I want to have to keep checking on the battery levels and ruining my shirt sleves with battery acid.

IMHO

Dallas 2004 intrigue ovation C12 11688 (1)starter battery (4)AGM House Batteries, all 8D's

Re: Battery matching and aging

Reply #19 –
Yahoo Message Number: 66542
Jim,

It is not a complicated formula at all. Two batteries connected in parallel represent a relatively simple DC circuit. Because it is a 12v circuit anything you want to know about it can be calculated using Ohms Law and some simple circuit theory.
Without boring people with all that, due to the difference in age the two batteries have a different internal resistance when fully charged. Because of that current will flow in the loop from the newer battery toward the older battery. But the older battery is fully charged and cannot accept any further charge from the good battery. So the current flow continues dissipating the energy of the newer battery as heat loss until the newer battery's internal resistance is equal to the old battery. That means that the new battery has discharged some of its capacity as losses to heat and now it is equal to the older battery in terms of State of Charge. That is what is meant by the term that the old battery is a parasite to the new battery.
It is not the average of the two simply because the older battery cannot accept any further charge and Ohms Law says that current will flow until the two internal resistances are equal.

Hope it is not too confusing.

Don Seager

2004 Allure 31046

Re: Battery matching and aging

Reply #20 –
Yahoo Message Number: 66544
Don, that is true but not relevant. By definition you mix the type when driving down the road as most of us have deep cycle for the house and starting for the chassis. The reason it is not relevant is that the relatively short time spent on the alternator does not provide enough non-ideal charge regime to damage either set. Unless the alternator is charging at damagingly high voltage. Then both banks are at risk.

George in Birmingham
'04 Allure 31038
George in Birmingham
2003 Magna 6298

Re: Battery matching and aging

Reply #21 –
Yahoo Message Number: 66546
Sounds good to me. I can understand the parasite concept OK. Should have paid more attention to those physics courses in college - at least the part having to do with electricity and Ohm's Law. Something I really knew but haven't thought about for about 50 years. From what you say I'd gather that two batteries with significant different internal resistance when exposed in parallel to a charging current should result in the better (less resistant) battery should be warmer than the older(more resistant) battery when they reach an equilibrium while being charged.

Can this be felt? is the better battery hot to the touch?

Jim M.

'02Intrigue #11410 ISL 400

Re: Battery matching and aging

Reply #22 –
Yahoo Message Number: 66547
Jim,

If you need Lifeline Batteries, please contact me, I'm in the links section.

Tom

Trans-Specialist/Lifeline Batteries
01 Magna 5999

Re: Battery matching and aging

Reply #23 –
Yahoo Message Number: 66550
Ron: The question was: Should we maintain comparable battery age and type in DIFFERENT battery banks, for example in house and chassis batteries, not in the same bank.
I agree 100% on keeping house batteries of the same age and type.

Richard Owen '05 Inspire 51442

Re: Custom Battery Cables for motorhome

Reply #24 –
Yahoo Message Number: 66663
Thanks for sharing, Working for Cat I in my service truck had 2 and 4/0 cable and ends always put heat shrink red and Black. I used welding cable. Working on Boats I went to marine supply and got marine cable and ends. Make sure your cables dont chaff on metal and cause a fire! Ken 99 Allure 30356