Battery replacement

[biscuitwhistler37]

Anyone have the TM (if one exists) for the proper battery terminal/battery removal process for the A2? I have searched my manual and many threads on here, plus web, and nothing.

 

[G744]

Ground Negative first off, last on.

The rest don't really matter, just be careful not short a battery with a tool.

 

[biscuitwhistler37]

Thank you

 

[WillWagner]

I kinda like to do the dogbone first. Removing it isolates the batteries so that there is no completed circuit and no chance of arcing if a tool touches metal.

 

[WillWagner]

And, the TM shows/instructs to do it like G744 said to do it.

https://www.steelsoldiers.com/upload/M35/TM9-2320-209-20-3-1.pdf

Section 7-56, page 7-210

 

[G744]

One tends to touch metal with tools when doing battery service only once; It leaves a lasting impression!

 

[WillWagner]

One tends to touch metal with tools when doing battery service only once; It leaves a lasting impression!

Usually only one time, 24VDC makes alot of sparks!

 

[biscuitwhistler37]

And, the TM shows/instructs to do it like G744 said to do it.

https://www.steelsoldiers.com/upload/M35/TM9-2320-209-20-3-1.pdf

Section 7-56, page 7-210

THIS!!!!! Thank you!!!

 

[biscuitwhistler37]

I kinda like to do the dogbone first. Removing it isolates the batteries so that there is no completed circuit and no chance of arcing if a tool touches metal.

Wonderfully enough, my dogbone has been replaced with an interrupt switch, mounted in what I'm guessing is an A3 plastic box (this is my first MV and previous owner didn't go into much detail). The switch works, so when it's off, the batteries are isolated the same way as if the dogbone were disconnected, correct?

 

[WillWagner]

There were plastic boxes in the A2s too, and yes, isolated/turned off with the switch in disconnect.

 

[SCM35A2]

There were plastic boxes in the A2s too, and yes, isolated/turned off with the switch in disconnect.

Yes, my truck was upgraded to a plastic box so I went with group 31 batteries & replaced all my cables!

 

[ToddJK]

Make sure to use group 31 batteries, something deep cycle with at least 900CCA, most other batteries either won't be strong enough, crank it long enough, or won't fit. Years ago I used some dozer batteries from a heavy equipment shop and those were 980CCA each, turned the deuce over pretty fast, but some batteries once they go dead, they don't like to take a charge again, which is why group 31 remains an excellent choice! It's also worth it to put a battery equalizer on there, keeps both at the same level as the alternator charges the first one the most in the series.

 

[biscuitwhistler37]

Make sure to use group 31 batteries, something deep cycle with at least 900CCA, most other batteries either won't be strong enough, crank it long enough, or won't fit. Years ago I used some dozer batteries from a heavy equipment shop and those were 980CCA each, turned the deuce over pretty fast, but some batteries once they go dead, they don't like to take a charge again, which is why group 31 remains an excellent choice! It's also worth it to put a battery equalizer on there, keeps both at the same level as the alternator charges the first one the most in the series.

Thank you, I'll be digging through my battery collection and see what I come up with. Hypothetically though if I ran a 1010cca first in series and a 980 second, would that balance until I get an equalizer?

 

[biscuitwhistler37]

just a couple pics of my box setup. Glad I've got you guys, the system is way more intimidating than intensive, but then from what I've read the entire truck is. Cleaned up the wires too, no more 12v trailer lights half rigged in with a fuse..... Thank you everyone for the help

 

[ToddJK]

Thank you, I'll be digging through my battery collection and see what I come up with. Hypothetically though if I ran a 1010cca first in series and a 980 second, would that balance until I get an equalizer?

It's not the CCA you have to worry about as far as balance goes, but the actual energy level of the battery itself. One might be at 12.5 amp and the other is at 11.8 amp. What happens is when the voltage regulator sense that the voltage is off, whichever of the two batteries, but it's usually the one on the primary ground cable, the alternator will charge and charge until it reads proper voltage. This over charges and cooks the first battery in the series (the one on the primary positive cable) and causes it to go bad and then the other battery will in time go bad from having a lower charge all the time. This also causes overcharging on many of the deuces where you see the gauge bottom out and the lights get brighter, ect. This isn't good on the alternator either. An equalizer can be had fairly cheap, like under $50 in most cases, but even an expensive one will save you money in the long run. Without one, don't be surprised if the batteries barely last a few years, with one, they will last much longer. One way to help mitigate this without an equalizer would be to rotate the batteries every so often depending on how often you start and run your truck. That's probably one of the biggest downsides with the 24V system using batteries in series.

 

[NY Tom]

What else can you do? Rotate the batteries occasionally?

 

[biscuitwhistler37]

Update: charged one of the batteries for 12.5 hrs, discarded the second one and replaced it with an old napa I had, hooked everything back up, cranked and about unhinged my jaw from smiling so hard. After sitting in the "cold" for a week, 5 cranks and she fired. Runs great, smokes a little white for my liking, I'll be posting about that later in a different place, but a big thank you to everyone for the advice, and I will say, battery interrupts are a MUST. I dropped my wrench and it landed across the battery terminals, but with the switch off, not a single spark. I highly advise those reading this thread who have thought about a switch but haven't put one in yet to do it, the peace of mind is irreplaceable. Again, many many many thanks.

 

[ToddJK]

What else can you do? Rotate the batteries occasionally?

You can yes, you can see this first hand using a voltage reader, you'll see over time one battery has more amps than the other. Sometimes after a drive you can hear hissing coming from the battery on the primary positive cable. This is due to over charging as the system is trying to pass the voltage through the first battery into the second. I've had two equalizers from Amazon over the past few years and one quit within six months, the other still works after a year and a half. Both were less than $40. Still cheaper than new batteries at $150+ each, lol.

 

[ToddJK]

Update: charged one of the batteries for 12.5 hrs, discarded the second one and replaced it with an old napa I had, hooked everything back up, cranked and about unhinged my jaw from smiling so hard. After sitting in the "cold" for a week, 5 cranks and she fired. Runs great, smokes a little white for my liking, I'll be posting about that later in a different place, but a big thank you to everyone for the advice, and I will say, battery interrupts are a MUST. I dropped my wrench and it landed across the battery terminals, but with the switch off, not a single spark. I highly advise those reading this thread who have thought about a switch but haven't put one in yet to do it, the peace of mind is irreplaceable. Again, many many many thanks.

Great to hear! I agree, battery disconnects are a great accessory to add to any MV as many suffer from parasitic draws, but also eliminates other potential issues.

 

[biscuitwhistler37]

It's not the CCA you have to worry about as far as balance goes, but the actual energy level of the battery itself. One might be at 12.5 amp and the other is at 11.8 amp. What happens is when the voltage regulator sense that the voltage is off, whichever of the two batteries, but it's usually the one on the primary ground cable, the alternator will charge and charge until it reads proper voltage. This over charges and cooks the first battery in the series (the one on the primary positive cable) and causes it to go bad and then the other battery will in time go bad from having a lower charge all the time. This also causes overcharging on many of the deuces where you see the gauge bottom out and the lights get brighter, ect. This isn't good on the alternator either. An equalizer can be had fairly cheap, like under $50 in most cases, but even an expensive one will save you money in the long run. Without one, don't be surprised if the batteries barely last a few years, with one, they will last much longer. One way to help mitigate this without an equalizer would be to rotate the batteries every so often depending on how often you start and run your truck. That's probably one of the biggest downsides with the 24V system using batteries in series.

That would explain why the forward battery needed replacement, well that and it was a 7 year old everstart that was too small for the truck to begin with (750cca and 850@32°). Definitely getting an equalizer before I put brand new batteries in, but for now there's higher priority items. Thanks for all your help, much appreciated![/QUOTE]