I've dug through the threads here and I'm still scratching my head, so I figured it might be easier just to ask this question again:
To replace a couple of 8D's, what is the minimum CCA I can get away with for an older 892 (non DDEC and no air)? I found a lot of threads discussing Group 31's, but they are actually available in many amp sizes. And do I really need 3 of them or will 2 do the trick?
Thanks, Will
I use 2 group 27's. (in series for 24V)They are 1000 CCA each. It won't have the cranking time of the big ones but they have never failed me.
Don
You need 2 or 4 for 24 volts the cranking amps stay the same with 1 or 4 that never changes only the reserve changes
Group 31 batteries are the choice for most all big rig trucks and many buses. Hence you can get them at any truck stop and most heavy duty truck supply. Interstate makes a 950cca battery. I have 2 on my 8V-71 high compression and always cranks (12v system). What I also have is a jumper solenoid to my 2-8D deep cycle batteries to charge them going down the road, to charge the starting batteries when parked, and to jump the starting batteries if they are dead-and have started the bus that way. Then if you're in cold weather and need to crank alot, just activate the jump right off the bat and you have 4 batteries for cranking. Good luck, TomC
Will, DD says 800 amps for the Delco 42 starter and 8v92 so 2-950amp to 2-1100 amps should work just stay in the warm country
Thanks for the quick replies and helpful advice. After having my last 8D fail at the 3 yr mark from NAPA and they only come with a 6 month warrenty because they're classified 'Commercial', I am convinced now that replacing them with 2 grp 27 or 31 bats is the way to go. O'Reilly's grp 31 comes with a 3 year free replacement and pro-rated for another 4 yrs after that. Plus I can replace both for the price of replacing just 1 of the 8Ds. Right now I'm jumping off the 12V house bank to make my 24V because the old 8D (8 yrs) is still holding a charge despite having one cell going down (hygrometer says so and voltage is dropping from 12.58 to 12.04 in a week of setting).
Again thanks for the responses and setting my mind at ease. BTW I wish I could stay where the weather was always warm, but since I've rejoined the workforce, that's not much of an option. Still recuperating from the 2008 recession lol.
Just don't go above 1250 CCA for your 24v starter it will destroy the old 42 starter
Do you use the cranking batteries also for house battery?
Quote from: chessie4905 on July 08, 2014, 02:17:08 PM
Do you use the cranking batteries also for house battery?
No, I have 6- 6volt deep cycles for the house bank. they're going on 8 years also, since I replaced them when I originally replaced the 8D's. Since then, I've had to replace one of the 8Ds 3 years ago and that's the one that's gone bad already. The house batteries all check out excellent, especially considering their age. When parked the house bats are on a Heart 2000W inverter/charger set at 12.32 float. The start bats each have their own little battery tenders which are questionable at best.
I just lost both mine over the weekend and found these at NAPA seem pretty good for $79.99 each with a 36 month warrentee and free replacement for 1 year.
I am going to get 4 of them. Any thoughts of these?
Part Number: BAT 7236
Product Line: NAPA Batteries
Attributes:
Battery BCI # : BCI # 31S
Battery Cold Cranking Amps @ 0 Degrees F : 950
Battery Cranking Amps @ 32 Degrees F : 1,190
Battery Load Test Amps : 475
Battery Posts Type : Top Mount Stud
Battery Reserve Capacity (Minutes) : 195
Battery Voltage : 12 Volt
Wet or Dry : Wet
Battery Application : Commercial
Battery Load Test Amps : 475
Battery Weight : 59.9 lbs
Contents : (1) Battery
Height : 9-7/16"
Length : 13"
Seems ok Dave the weight is average for most G-31 batteries you should be ok hell I just gave 107 bucks for a pickup battery from O'Rilies G-24 size
Clifford thanks just saw the thread and thought I would put that in. Sam's Club was 112.87 for one.
Dave,
the local NAPA here wants 119. exch for that battery. They must be on a super sale where you're at.
Nope it is the Northern Cali distribution center and they supply a lot of the trucking companies as well as CAL-FIRE, local municipalities, etc and have these pretty regularly. Lucky for me they are only 2 miles from me. Really big NAPA store with a big rig counter in the back. ;D
Dave5Cs
On my truck, I use 4-31 Interstate batteries that have a series parallel switch for the 24v starter, but everything else runs on 12vdc. With the 4-950cca batteries, that works out to be 1900cca at 24vdc. In 1.2 million miles on the truck, I have replaced the starter once. Doesn't seem to hurt the starter with a lot of batteries. Good Luck, TomC
Delco sets a limit on CCA on their starters that is why they have a OP feature on their starters 1 or 20 batteries the 1st battery in a string sets the cold cranking amp Delco says 1250 CCA for the 42 and 1500 CCA for the 50 at 24 volts that is from Delco the newer reduction type starters will handle up to 3000 CCA fwiw so says Delco
I'm gonna go with just 2 of the G31s and use the extra space for a nice battery charger/maintainer. The bus starts so good you don't even hear it turn over before it's running. And I use the preheat even in the summer if I'm hooked up to a pod.
Unless you are getting AGM group 31's I don't think it would be a good idea to put a battery charger/ Maintainer in the same compartment as them. A spark or any Gasing may present a big problem. :o
Dave
Quote from: Dave5Cs on July 10, 2014, 06:31:25 PM
Unless you are getting AGM group 31's I don't think it would be a good idea to put a battery charger/ Maintainer in the same compartment as them. A spark or any Gasing may present a big problem. :o
Dave
That's a good point Dave. Maybe I'll just replace the 2 little 12V battery tenders that I have now. They're mounted just to the right of the rear electrical panel above the engine and are connected together to deliver 24V at the batteries. So what does someone do with all that open space? LOL
You are fulltimers and have empty space?......that won't last for long!!!!!
Got the new ones in today and she started right up. Seemed a lot more powerful also. I gave them 2 old regular car batteries we had here for the 22.50 core and sold them another for 15.00. So they ended up costing me 35.38 each, SCORE, Lol. I got 36.50 apiece for the old dead 8Ds each and 31.00 each for 6V deep cycles so they sold those to me for 100.00 each US XC 2200 232AH @ 20 rate.
Not a bad day.
PP do you just bolt the +&- wires together on the 12 volt charger maintainers and charge from the ends of each to get 24V. I didn't know you could do that and then plug both units in. Because I have been using 2 chargers and pulling the link between the 2 6volts and the other 6 volts and then charging them up when we are not on the road. I have got to get time to hookup our new Magnum inverter/ charger.
Dave
If you are using two 12v maintainers for a 24v bank you would connect a charger to each of the 12v batteries
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Nope have 4-6 volt batteries. In series but don't have my inverter hooked up yet with the charger. So right now I pull the link between the 2 6's and the other two 6's which leave two in each bank for 12 volts. I hook a 12 volt charger up to the neg and pos on the end ones and there is a link between them. Works fine but I have to put the link back on and off for 24 volt or charging.
I thought he said that he used 2 12 volt chargers is series to charge all 4 at once without having to separate them while charging. Was just wondering how that was possible and if you could connect both chargers +- and then use the end +- for 24 volts?...Wishful thinking, lol
As far as open space I don't have much more space than I had with the 8D's. I have a short 2x4 screwed in next to the batteries because they have to go in front to back long ways. So there is about 4 inches on one side and 7 inches behind them or I guess I could shove them back and have some room for battery tools etc.
The Batteries are sealed top lead acid filled so no putting in water but will really have to watch length of charging and always shut off batteries when not in use.
Dave
You could do basically the same thing as I stated before with the 4 6v batteries. You have 4 6v batteries all daisy chained together to get 24v. The first 2 batteries are essentially the same as a single 12v battery, same with the second two batteries. Connect one charger to the first pair of batteries (+ on one battery and - on the other) and connect the second charger to the second pair of batteries. Do not connect the chargers to each other. No need to disconnect any cables between any of the batteries. Ive done it this way for years work fine.
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Quote from: thomasinnv on July 14, 2014, 06:16:31 AM
You could do basically the same thing as I stated before with the 4 6v batteries. You have 4 6v batteries all daisy chained together to get 24v. The first 2 batteries are essentially the same as a single 12v battery, same with the second two batteries. Connect one charger to the first pair of batteries (+ on one battery and - on the other) and connect the second charger to the second pair of batteries. Do not connect the chargers to each other. No need to disconnect any cables between any of the batteries. Ive done it this way for years work fine.
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Cool thanks It is a pain to keep going back and forth pulling the middle cable out. I really just have to get time and install the inverter/ charger.
Dave
Quote from: thomasinnv on July 14, 2014, 06:16:31 AMYou could do basically the same thing as I stated before with the 4 6v batteries. You have 4 6v batteries all daisy chained together to get 24v. The first 2 batteries are essentially the same as a single 12v battery, same with the second two batteries. Connect one charger to the first pair of batteries (+ on one battery and - on the other) and connect the second charger to the second pair of batteries. Do not connect the chargers to each other. No need to disconnect any cables between any of the batteries. Ive done it this way for years work fine.
I have two Type 31 start batteries. That's how I connect a trickle charger (about every 2-4 weeks, until it goes to "float"; usually less than 15 minutes). I've never tried it with the master switch on, only with the battery pair isolated.
Hey Dave, sorry I was so long in getting back, we had an electrical storm pass through and I've been busy with fires. Anyway, I agree with ThomasinNV about not hooking the 2 maintainers together to get 24V, but that's the way Marathon or the electrical engineer wired the 2 I have. The electrical engineer was the only owner prior to us and I think he knew what he was doing LOL. I agree with Thomas, I've charged batteries in series like that before by simply connecting the charger to one at a time and not disconnecting anything. Maybe that's why my maintainers don't seem to be working. The wiring goes straight to the master disconnect switch so that if the batteries are connected, the chargers aren't in order to protect them, as well as a fuse inline.
Now get that inverter/charger installed and you won't have to constantly jerryrig everything LOL
Will
I am a little nervous about hooking it up only because this bus has been a wiring nightmare and was all house 12 volt and the original 24 volt bus circuits. I changed to 24 volt and now have to run the 12 volt off the Vanner that I have to test. don't know if it is a working unit or not. The original inverter was burned out when we got it and will hook up the new one when I am sure that all is well. Taking it slowly.
Things like different colored 12 volt wires spliced together every 6 inches and different sizes. Some peoples kids ya know!... :o
Dave
I've hooked two chargers/maintainers together to get 24 volts many times, in fact until I got the Magnum 4024 it was normal for me. the 12 volt output of most chargers (all of mine but that's a sample of about 5) is fully floating with respect to the 120 volt ac plug, so no issue whatsoever with connecting two together. What I would do is just connect them to the start batteries leaving the start batteries connected normally, so in effect the positive 12v of one charger is connected to the ground of the other charger.
Brian
Brian beings we both have 5C, one of my biggest problems is where to put the 4 6volts house bats, and the inverter. Generator is in the old AC bay and just outside in the next bay back on the wall is the transfer switch. Right now the PO put the batteries all the way in the back passenger side engine bay on a rack that holds all 4 in a line by the side door. The old cable went up through the floor along the wall 10 feet through the bedroom and into the closet. That is also where he ran the 120VAC Romex cable to meet the inverter from the transfer switch. I believe this is why the old Freedom 20 burned up for him in the closet because the cable was so long. My start batteries are in the original place on the slide out trays and are not part of my house batteries system. Starts are on off when sitting and I have a converter that charges them when needed or the 24 volt Alt when traveling.
Question to you is if you don't mind telling me, where did you put your house batteries and where is the inverter.
Dave Walker
My generator (Yamaha 3000 watt inverter) is in the front half of the AC condenser bay, and the four 6 volt golf cart batteries are where the AC condenser fan used to be (cut out the fan housing and installed a floor). Lots of ventilation. Directly rear of that I built a wall along the length of the first luggage bay to section off about 2 feet along the drivers side. On the front wall of the bay is an automatic transfer switch to switch between external power and generator power, and the external Marinco plug is on the outside of the bus right there. Mounted to the new plywood internal wall is the battery A/B combiner switch, the Magnum inverter, the inverter AC distribution panel and the big DC fuse, and the Vanner battery equalizer. I run a 24 volt house system for the inverter and use the Vanner to equalize for the 12 volt house loads. The battery combiner switch lets me bridge the house batteries to the start batteries and the alternator. Up inside the bus is the non-inverter AC distribution panel ( used to be a DC converter/charger but I took the charger section out and just use it as a distribution point now) and the DC distribution for the house, along with the Magnum control panel. I use home-run wiring for all the house DC, with the fuse section from the old converter and a ground bus bar. Works great, if I do say so myself!
Brian
Dave, my 4 golf cart batts are on a tray in the pass side rear corner of the engine compartment. The inverter is at the rear pass side of the rear cargo bay. My 2 group 31 start batts are in the original start batt compartment. The generator is on the driver's side of the rear bay.
JC
The problem I see with connecting two chargers together to get the higher output voltage is that if one of the batteries is discharged more than another, the batteries will never get equal charging. The lower battery might never get fully charged or the other batteries might get over charged. If nothing is being tapped off of the middle of the bank it might never be an issue, but if a center tap is being used it could definitely be an issue. Also if one battery failed you could potentially damage the rest of the bank.
JMW and to each his own.
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Brian thanks, you gave me some good ideas. I put in a plywood wall also 18 inches in but I use it for the generator battery, transfer switch, and storage for extra Delo 100, filters a few air bags, grease etc. But i could move that back to the passenger side rear engine compartment although then I would have to put a lock on all rear and rear side doors, lol
I could put the Batteries in there and maybe the inverter would fit in its own compartment there also.
JC, thank you also, but my generator is staying where it is only because it is pretty big 15KW 3 cylinder Kohler and would not fit back there. I would have to build a platform over the muffler which is there as well, air filters, big transmission filter and the inverter would still be to far away from batteries.
for a 4024 the loss in power would be extreme. The engine heat is probably not real good for it either from what the manual says.
Derrick that is a good point and until I have the inverter hooked up with the vanner in the loop I will keep the two sets of 2 6volts un linked and charging with 2 charger maintainers, because I do have a 12 volt tap coming off 2 of them and the whole bank is 24 volt.
Thanks Guys Dave ;D
Derrick you are absolutely correct, but it's no different than my Magnum charging four six volt batteries in series at 24 volts. You always have that issue, even a normal 12 volt battery has it since it is nothing but six two volt batteries in series. The way I did it by leaving the cable connecting the two batteries in place I am basically using each charger to charge one battery, so I get the same result you do. I don't know a way around the batteries in series issue, if one is weak or loses a cell it is a problem. I lost a cell in one of my start batteries on my last trip, had to run 1600 km before I got to a place where I could swap out the batteries. Nothing to do when that happens, I just disconnected the starts and ran everything off the house batteries for a day and a half. Which is a great advertisement for a 24 volt house bank, I happen to think!
Brian
If the battery switch is turned off how often do you guys charge your start bats if the coach is parked for awhile?
Dave
Hi Dave, typically the battery maintainers will top off the charge and then start up again after a 1 volt drop, lvmci
I have the bus converter that I have to turn on. I have maintainers on the house only. In the past I was turning them on once a week and it seemed to keep them up and don't know how old they were when we bought the bus. We have had it for about 3 years and then last weekend they were done. Now with new ones I just shut off the batteries when not using the bus and check them every few days.
Dave
Quote from: Dave5Cs on July 16, 2014, 07:14:32 AMIf the battery switch is turned off how often do you guys charge your start bats if the coach is parked for awhile? Dave
If you're plugged in (shore power), you can just plug your maintainer(s) into a house 120 socket. Or, if you're running the gennie or charging off solar for hot water, house battery charging, etc. ditto.
OK let me splain again Lucy!.... :D I don't have a maintainer on the start bats. I have a converter that came with the bus and is the big box in the bay. I have a switch in the bus that says coach Batteries on the switch panel. Every week I turn that on to give a sprits to them for a few hours and then off for another week. We are plugged into the house when parked.
I will check into a couple more maintainers i guess.
Charging for a few hours a week is just fine, no issues with that. Maintainers are just a bit more automatic.
Brian
Quote from: bevans6 on July 16, 2014, 07:54:33 AMCharging for a few hours a week is just fine, no issues with that. Maintainers are just a bit more automatic. Brian
I only put my "maintainers" (Stanley "smart chargers") physically on the batteries when I'm doing a checkup charge. If I park the bus, turn off the master switch, and put the little chargers on each battery after the bus has sat for 2-3-4 weeks, they'll usually go to "float charging" in 8-12 minutes. Then I unplug them, take them off the start batteries, and put them away (and generally use them for other things from time to time).
Dave, I don't know exactly how you connect your batteries together (if I understand it right, you let the two banks equalize a charge). I don't know enough to know exactly how that balances the start batteries to get exactly right up to 100% charge, but if it works, it works (and I'm happy with anything that works!)
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi45.photobucket.com%2Falbums%2Ff60%2Foonrahnjay%2FBus%2FCharger_zps6f3495c8.png&hash=a2436e63840c3a70a0487c2637a02f36a5ef76ab) (http://s45.photobucket.com/user/oonrahnjay/media/Bus/Charger_zps6f3495c8.png.html)