Chassis Battery Temps

Topic: Chassis Battery Temps (Read 740 times) previous topic - next topic

Chassis Battery Temps

August 13, 2018, 12:21:11 pm

Question on battery temps. Noticed my 3 Optima Red Tops all have different temps when hand testing them. 1 warm 1 luke warm 1 cold. Thought it maybe dirty teminals or bad cell. Cleaned everything and load tested them .Results on all were the same. 400amp draw for 15 seconds pulled the volts down to 11. Seems normal. After hooking the Charger back up still doing the same temp thing.

Any ideas as to cause or should I not worry about ?

Thx

Hans

Re: Chassis Battery Temps

Reply #1 – August 13, 2018, 12:25:01 pm

Hans,

With three 12 VDC in parallel (positive to positive to positive and negative to negative to negative), does the positive cable to load come off battery #1 and the negative to ground off battery #3? That should balance the loads reasonably well.

Re: Chassis Battery Temps

Reply #2 – August 13, 2018, 12:28:35 pm

Quote from: wolfe10 – August 13, 2018, 12:25:01 pm

Hans,

With three 12 VDC in parallel (positive to positive to positive and negative to negative to negative), does the positive cable to load come off battery #1 and the negative to ground off battery #3? That should balance the loads reasonably well.

Yes they are hooked in parallel but Neg & Pos are hooked to center battery.

Re: Chassis Battery Temps

Reply #3 – August 13, 2018, 12:36:50 pm

Quote from: Hans&Marjet – August 13, 2018, 12:28:35 pm

Yes they are hooked in parallel but Neg & Pos are hooked to center battery.

That is not the preferred way. Brett is telling you to get the positive off one end of the battery bank and the negative off the other end.

Re: Chassis Battery Temps

Reply #4 – August 13, 2018, 12:54:13 pm

Quote from: craneman – August 13, 2018, 12:36:50 pm

That is not the preferred way. Brett is telling you to get the positive off one end of the battery bank and the negative off the other end.

That's how the cabling was setup (center battery). Is there a source for the other cable arrangement ?

Re: Chassis Battery Temps

Reply #5 – August 13, 2018, 12:59:50 pm

I would be surprised if the cables are not long enough to allow the #1/#3 cable attachment.

Re: Chassis Battery Temps

Reply #6 – August 13, 2018, 01:06:48 pm

Quote from: wolfe10 – August 13, 2018, 12:59:50 pm

I would be surprised if the cables are not long enough to allow the #1/#3 cable attachment.

They may reach the #1#3 arrangement but I would need to make/buy the actual battery connection setup.

Re: Chassis Battery Temps

Reply #7 – August 13, 2018, 01:12:18 pm

How are you taking the temps? Some of the IR guns show different temps with different colors.

Re: Chassis Battery Temps

Reply #8 – August 13, 2018, 01:13:59 pm

Picture? there may be a simple solution.

Re: Chassis Battery Temps

Reply #9 – August 13, 2018, 01:19:06 pm

Our three engine batteries came with a pre-made cable assembly from Foretravel for both the positive and negative sides. Since it seemed to be working fine, I never bothered to make a custom assembly. I did add an extra ground cable to a close by frame rail. As I remember, it feeds off the center battery.

Pierce

Re: Chassis Battery Temps

Reply #10 – August 13, 2018, 01:36:29 pm

Quote from: Pierce & Gaylie Stewart – August 13, 2018, 01:19:06 pm

Our three engine batteries came with a pre-made cable assembly from Foretravel for both the positive and negative sides. Since it seemed to be working fine, I never bothered to make a custom assembly. I did add an extra ground cable to a close by frame rail. As I remember, it feeds off the center battery.

Pierce

I'll try the extra ground cable also. But how are the battery temps Pierce with your setup ?

Re: Chassis Battery Temps

Reply #11 – August 13, 2018, 02:09:19 pm

I've only checked by feeling them but they lasted almost 9 years. Even in subfreezing, the engine turns over really fast. No compression

?

Photo below shows OEM with center tap. When I installed the 31 series, I turned them around so the positive is at the back bumper. Since the 31s are longer and taller, the positive was too close to the hydraulic reservoir. You can see where I added the extra ground.

Pierce

Re: Chassis Battery Temps

Reply #12 – August 13, 2018, 03:27:06 pm

Quote from: Pierce & Gaylie Stewart – August 13, 2018, 02:09:19 pm

I've only checked by feeling them but they lasted almost 9 years. Even in subfreezing, the engine turns over really fast. No compression ?

Photo below shows OEM with center tap. When I installed the 31 series, I turned them around so the positive is at the back bumper. Since the 31s are longer and taller, the positive was too close to the hydraulic reservoir. You can see where I added the extra ground.

Pierce

Same setup as mine....Thx Pierce

Re: Chassis Battery Temps

Reply #13 – August 13, 2018, 03:51:45 pm

Hans,

Is the center battery the hot one? If so, redoing connections may be worth while. If it is one of the end ones, it will not help.

And, it is quite possible that you need to buy nothing. Look at just turning around the existing links between the batteries.

Re: Chassis Battery Temps

Reply #14 – August 13, 2018, 04:06:25 pm

If nothing else swap the center battery with the inboard or outboard battery to see if it makes a difference. This wiring scheme puts more load on the center battery than the other two.

Even if you have three start batteries connected together and the plus coming off one end and the minus off the other end rotating battery positions every year or so will help them all last longer. Same with your 3 house batteries.

Re: Chassis Battery Temps

Reply #15 – August 13, 2018, 05:09:33 pm

Quote from: wolfe10 – August 13, 2018, 03:51:45 pm

Hans,

Is the center battery the hot one? If so, redoing connections may be worth while. If it is one of the end ones, it will not help.

And, it is quite possible that you need to buy nothing. Look at just turning around the existing links between the batteries.

No, its the 3rd battery...center is luke warm, 1st cold

Re: Chassis Battery Temps

Reply #16 – August 13, 2018, 05:10:47 pm

Quote from: Roger & Susan in Home2 – August 13, 2018, 04:06:25 pm

If nothing else swap the center battery with the inboard or outboard battery to see if it makes a difference. This wiring scheme puts more load on the center battery than the other two.

Even if you have three start batteries connected together and the plus coming off one end and the minus off the other end rotating battery positions every year or so will help them all last longer. Same with your 3 house batteries.

Great idea Roger I'll try it and see what happens....

Re: Chassis Battery Temps

Reply #17 – August 13, 2018, 05:17:22 pm

Hans,

While redoing them, might want to take them in for a load test. Be sure they are all fully charged first.

The outside batteries should be cooler than the center because of both charging amps and less air circulation.

Re: Chassis Battery Temps

Reply #18 – August 13, 2018, 05:30:32 pm

Quote from: wolfe10 – August 13, 2018, 05:17:22 pm

Hans,

While redoing them, might want to take them in for a load test. Be sure they are all fully charged first.

The outside batteries should be cooler than the center because of both charging amps and less air circulation.

They all load tested Ok, 400 amps for 15 sec ....draw down to 11 volts

Re: Chassis Battery Temps

Reply #19 – August 13, 2018, 09:05:44 pm

Don't use premade cables with permanent battery post terminals attached.

Use separate 'military' battery post connectors with separate short lug end cables between each battery. Then connect coach cables to opposite ends of battery bank. When a battery post terminal fails just replace it, and not deal with cable.

When ends are permanently attached, and they partially fail owners continue to use them even with problematic connections, as to replace the whole triple end cable when only one connection is bad seems difficult.

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