2001 u320 chassis battery question

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2001 u320 chassis battery question

January 19, 2025, 05:52:59 pm

Good afternoon everyone, I'm new on here and only recently purchased a 2001 36' u320. There are 3 12v 31T starter (chassis?) batteries I want to replace with AGM. The issue is that I was recently told to look at the converter because depending on the age it may have to be manual changed? Is this correct?

I also have 3 agm 8d house batteries I may replace later, but I believe they're fine and just in need of some cleaning.

Re: 2001 u320 chassis battery question

Reply #1 – January 19, 2025, 07:42:36 pm

I mix my house AGMs with the chassis 31 conventional series and charge both together. No problems.

Pierce

Re: 2001 u320 chassis battery question

Reply #2 – January 19, 2025, 08:52:51 pm

Quote from: kenneth_kopal – January 19, 2025, 05:52:59 pm

Good afternoon everyone, I'm new on here and only recently purchased a 2001 36' u320. There are 3 12v 31T starter (chassis?) batteries I want to replace with AGM. The issue is that I was recently told to look at the converter because depending on the age it may have to be manual changed? Is this correct?

I also have 3 agm 8d house batteries I may replace later, but I believe they're fine and just in need of some cleaning.

At minimum, you'll want to clean up that corrosion on the cables/battery posts/lugs. img4042 looks really nasty.

The OEM inverter (a 2001 won't have a converter, it will have an inverter/charger) was a Prosine 2.5. Can you identify which inverter is in your coach? Look in one of the basement bays for it and for the control panels behind the smoke plastic door mid-coach where the power line monitor with its green phosphor bulbs are.

If your house batteries are AGM and the inverter/charger is set for an AGM or flooded charging profile, you're good to go on changing the chassis batteries to AGM. Those battery types have a similar charging profile.

Where one runs into a potential concern is gel house batteries and flooded/AGM chassis batteries. MK Gel batteries (Foretravel's OEM house battery in 2001) require a different charging profile than AGM. If the inverter/charger is set for gel, AND you use something like a Trik-L-Start to use house batteries to maintain the chassis batteries when plugged in (a very specific case), the chassis batteries won't get fully charged via the Trik-L-Start; only when running the coach engine and charging via the alternator.

If you have the OEM Prosine 2.5, we do have the manual in the Files/Media section.

The selected media item is not currently available.

If yours also has the optional ACS panel (which makes changing settings significantly easier), here's the manual for it

The selected media item is not currently available.

Be aware these inverters are not repairable when they fail, so if you do still have the original one, you may want to proactively research a replacement. Lots of info on the forum for Victron Multiplus and Multiplus II installations. Others have opted for newer Xantrex models. Magnum apparently no longer supports the RV industry.

Re: 2001 u320 chassis battery question

Reply #3 – January 19, 2025, 10:18:41 pm

Welcome to the forum!
Something you may consider while you're messing with your batteries is to replace the two isolator post that I have circled in yellow in your picture. They have been known to cause problems because of corrosion and cause voltage issues and slow starts. . If you do decide to work on them a lot of times they break and you have to replace the with new posts or bus bars. The 2nd pic is an example of a redo that someone did to their batteries in a coach like yours. It's also best for each battery to have its own wire going to the bus bar like in the second picture. I was having a slow starting issue and changed the wires from the batteries to a new bus bar and it turns over like a brand new coach. The third pic is my coach...

Keith

Re: 2001 u320 chassis battery question

Reply #4 – January 19, 2025, 11:26:15 pm

I may be confused. The inverter/charger in my 98 coach only charges the house batteries, therefore if the charger is properly set up to charge your house batteries it doesn't make a bit of difference what chassis batteries you put in, they are only charged by the alternator when the engine is running. However, if you are leaving your boost switch on when plugged in to shore power and the inverter/charger is set to charge, then you would be charging both sets. The problem with that is three fold: you run the risk of running both house and chassis batteries into the ground with extended loss of power or failure of charger potentially ruining six batteries in one fell swoop; your battery chemistries may not be compatible; and not all boost switches are rated for continuous duty.

Many coaches have an echo charger of some sort that borrows from the house batteries to charge the chassis (start) batteries while parked. Trikl Start was popular, but it is out of business. You may have one, or a similar type of low amp maintenance charger powered by the house batteries or simply a 110 volt battery tender that must be plugged in while parked. You will need to do some investigation to see what is installed on your coach by any previous owners, and what still works. You should find it when cleaning up those battery cables.

Adding Lithium house batteries is a new wrinkle in time. Most echo-style chargers do not have a lithium to conventional charge setting. A version of the TrikL start did do this, but it is gone from the market.

A lot depends upon where you will store the coach and how much parasitic draw remains on the house and chassis batteries. The simplest solution is to disconnect the negative post of both house and chassis batteries while in storage after first giving them a good smart charge with an appropriate charger. Don't trust the salesman switch (battery disconnect at stepwell.) It may wound the electron parasites, but it doesn't kill them outright. When you reconnect the ground on the house batteries, keep the salesman switch off and make sure the charger/inverter is off. That charger will send about a 90 plus amp charge into the house batteries and it will make you jump. Many inverter/chargers default to charge upon being powered up. Unless you have a switch on the echo charger to turn it off, it's another immediate draw upon connection or disconnect that lives outside the salesman switch.

Good luck. It's very confusing at first and you never know what a previous owner or shop has done (right or wrong) to the coach. That slowly reveals itself as you chase a few gremlins and make it your own.

Re: 2001 u320 chassis battery question

Reply #5 – January 20, 2025, 09:42:08 am

Quote from: hdff – January 19, 2025, 10:18:41 pm

Welcome to the forum!
Something you may consider while you're messing with your batteries is to replace the two isolator post that I have circled in yellow in your picture. They have been known to cause problems because of corrosion and cause voltage issues and slow starts. . If you do decide to work on them a lot of times they break and you have to replace the with new posts or bus bars. The 2nd pic is an example of a redo that someone did to their batteries in a coach like yours. It's also best for each battery to have its own wire going to the bus bar like in the second picture. I was having a slow starting issue and changed the wires from the batteries to a new bus bar and it turns over like a brand new coach. The third pic is my coach...

Keith

Good morning Keith, I won't pretend to be savvy with vehicle electrical systems, but that does look much cleaner. What kind of bus bar is that and where did you get it?

Re: 2001 u320 chassis battery question

Reply #6 – January 20, 2025, 09:44:14 am

Quote from: Michelle – January 19, 2025, 08:52:51 pm

At minimum, you'll want to clean up that corrosion on the cables/battery posts/lugs. img4042 looks really nasty.

The OEM inverter (a 2001 won't have a converter, it will have an inverter/charger) was a Prosine 2.5. Can you identify which inverter is in your coach? Look in one of the basement bays for it and for the control panels behind the smoke plastic door mid-coach where the power line monitor with its green phosphor bulbs are.

If your house batteries are AGM and the inverter/charger is set for an AGM or flooded charging profile, you're good to go on changing the chassis batteries to AGM. Those battery types have a similar charging profile.

Where one runs into a potential concern is gel house batteries and flooded/AGM chassis batteries. MK Gel batteries (Foretravel's OEM house battery in 2001) require a different charging profile than AGM. If the inverter/charger is set for gel, AND you use something like a Trik-L-Start to use house batteries to maintain the chassis batteries when plugged in (a very specific case), the chassis batteries won't get fully charged via the Trik-L-Start; only when running the coach engine and charging via the alternator.

If you have the OEM Prosine 2.5, we do have the manual in the Files/Media section.

If yours also has the optional ACS panel (which makes changing settings significantly easier), here's the manual for it

Be aware these inverters are not repairable when they fail, so if you do still have the original one, you may want to proactively research a replacement. Lots of info on the forum for Victron Multiplus and Multiplus II installations. Others have opted for newer Xantrex models. Magnum apparently no longer supports the RV industry.

Thanks for the great info, I'll need to look at it later when it warms up. It's currently 10 here.

Re: 2001 u320 chassis battery question

Reply #7 – January 20, 2025, 01:40:29 pm

Quote from: Michelle – January 19, 2025, 08:52:51 pm

At minimum, you'll want to clean up that corrosion on the cables/battery posts/lugs. img4042 looks really nasty.

The OEM inverter (a 2001 won't have a converter, it will have an inverter/charger) was a Prosine 2.5. Can you identify which inverter is in your coach? Look in one of the basement bays for it and for the control panels behind the smoke plastic door mid-coach where the power line monitor with its green phosphor bulbs are.

If your house batteries are AGM and the inverter/charger is set for an AGM or flooded charging profile, you're good to go on changing the chassis batteries to AGM. Those battery types have a similar charging profile.

Where one runs into a potential concern is gel house batteries and flooded/AGM chassis batteries. MK Gel batteries (Foretravel's OEM house battery in 2001) require a different charging profile than AGM. If the inverter/charger is set for gel, AND you use something like a Trik-L-Start to use house batteries to maintain the chassis batteries when plugged in (a very specific case), the chassis batteries won't get fully charged via the Trik-L-Start; only when running the coach engine and charging via the alternator.

If you have the OEM Prosine 2.5, we do have the manual in the Files/Media section.

If yours also has the optional ACS panel (which makes changing settings significantly easier), here's the manual for it

Be aware these inverters are not repairable when they fail, so if you do still have the original one, you may want to proactively research a replacement. Lots of info on the forum for Victron Multiplus and Multiplus II installations. Others have opted for newer Xantrex models. Magnum apparently no longer supports the RV industry.

Just looked, we have a magnasine inverter/charger.

Re: 2001 u320 chassis battery question

Reply #8 – January 20, 2025, 02:32:00 pm

Quote from: kenneth_kopal – January 20, 2025, 09:42:08 am

Good morning Keith, I won't pretend to be savvy with vehicle electrical systems, but that does look much cleaner. What kind of bus bar is that and where did you get it?

Sent you a pm

Keith

Re: 2001 u320 chassis battery question

Reply #9 – January 20, 2025, 06:32:39 pm

Quote from: kenneth_kopal – January 20, 2025, 09:42:08 am

What kind of bus bar is that and where did you get it?

That is a BEP/Marinco buss bar, probably the 650A version. You can find them on Amazon and Bay Marine Supply Amazon recently had a sale and had them for $55 each, still pricey but a good deal given the normal price.

Bay Marine Supply BEP Products

BEP Buss bars

If you order thru BMS use the code FFMEMBER to get a discount, usually 5-10% depending on the product.

If you are not comfortable doing electrical work, be warned that the amps involved in a battery bank can certainly cause personal injury.

Here is an example for someone wearing a ring and making an accidental +/- connection

Re: 2001 u320 chassis battery question

Reply #10 – January 20, 2025, 06:53:51 pm

OUCH!

Re: 2001 u320 chassis battery question

Reply #11 – January 20, 2025, 10:24:14 pm

That's what I say! Lucky you didn't loose that finger.

Re: 2001 u320 chassis battery question

Reply #12 – January 23, 2025, 12:01:08 pm

Saw that exact thing happen to a shop owner I worked for 45 years ago. He was changing a Chevy starter motor, his ring shorted from positive post to block when he pulled away it peeled his finger like a grape. Since then I will never wear my ring while working with my hands on anything!! Jim.

Re: 2001 u320 chassis battery question

Reply #13 – January 23, 2025, 12:49:29 pm

10 Things You Should Never Do With Your Wedding Ring On:

10 Things You Should Never Do With Your Wedding Ring On | Enso Rings

Is it dangerous to wear a wedding ring while working out or doing activities...

Keep the ring in the jewelry box, a ring does not make a marriage, and a marriage does not make a ring

Re: 2001 u320 chassis battery question

Reply #14 – January 23, 2025, 10:21:40 pm

As a mechanic I don't wear rings or watches with metal straps. When I got married my wife had got
me a ring and that weekend was the only time I wore it. Later she used it and other gold to make a
custom bracelet for here self.

Re: 2001 u320 chassis battery question

Reply #15 – January 24, 2025, 10:11:32 am

An alternative is silicone rings SafeRingz - Silicone Wedding Rings Proudly Made in the USA These are pretty popular with various trades.

Re: 2001 u320 chassis battery question

Reply #16 – January 24, 2025, 10:18:49 am

My Dad cut his ring off with a side cutter after frying it into his finger. His burn was much worse than the pic Steve posted above.
I've been wearing a silicone ring for about 10 years.

Re: 2001 u320 chassis battery question

Reply #17 – January 25, 2025, 11:30:16 pm

Why AGM? They're not enclosed. AGM are the absolute worst possible choice for long term, high amperage start batteries, period. Prove me wrong.

Quote from: kenneth_kopal – January 19, 2025, 05:52:59 pm

Good afternoon everyone, I'm new on here and only recently purchased a 2001 36' u320. There are 3 12v 31T starter (chassis?) batteries I want to replace with AGM. The issue is that I was recently told to look at the converter because depending on the age it may have to be manual changed? Is this correct?

I also have 3 agm 8d house batteries I may replace later, but I believe they're fine and just in need of some cleaning.

Re: 2001 u320 chassis battery question

Reply #18 – January 25, 2025, 11:36:31 pm

AGM batteries can come in start batteries or deep cycle batteries

Re: 2001 u320 chassis battery question

Reply #19 – January 25, 2025, 11:37:24 pm

They're lead acid batteries. Prove me wrong.

Re: 2001 u320 chassis battery question

Reply #20 – January 26, 2025, 12:56:45 am

Key word is "sealed" lead acid batteries.

Re: 2001 u320 chassis battery question

Reply #21 – January 26, 2025, 01:06:58 am

Nope...the key word is "LEAD".

Re: 2001 u320 chassis battery question

Reply #22 – January 26, 2025, 07:51:51 pm

Quote from: Woody & Sitka – January 25, 2025, 11:30:16 pm

Why AGM? They're not enclosed. AGM are the absolute worst possible choice for long term, high amperage start batteries, period. Prove me wrong.

Why the worst possible?

Re: 2001 u320 chassis battery question

Reply #23 – January 26, 2025, 08:27:36 pm

Quote from: oldguy – January 25, 2025, 11:36:31 pm

AGM batteries can come in start batteries or deep cycle batteries

The 2003 we had came with Optima AGMs (blue top) as start batteries and we always replaced them with the same.

The 2000 we have now came with yellow-top Optima AGMs as start batteries; at some point those were changed to sealed LA, and we have since changed them back to yellow-top Optima AGMs.

Per Optima, the only difference between blue and yellow top are the posts. Both are deep cycle and suitable for use as starting batteries.

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