| Author | Message | ||
| StarDust Coach (67.3.155.161) Rating: N/A |
Hi All have a pair of 8/d batterys that its time to replace after 40 months. I am thinking about going to 31 series this time wondering about any draw backs? | ||
| TWO DOGS (4.227.117.161) Rating: N/A |
I just put two new 8d's in...if I had it to do over I would have put car batteries in | ||
| R.C.Bishop (128.123.221.139)
Rating: N/A |
2D.......why? (for what particular reason(s)?) Thanx.  RCB '64 Crown HWC | ||
| Johnny (4.174.112.186) Rating: N/A |
Probably cost & availability. 2 8D's are really overkill. | ||
| Robert Munrow (209.109.232.237)
Rating: N/A |
INSURANCE I have looked in the archives for insurance rates. I know this board has a link to rv insurance. I got a quote from them at 940 dollars a year. a year ago i was quoted 760 a year from them. I have read messages from 185 a year to 356 a year for full coverage. the fellow that was 356 lived in new york and was insured for 122,000. I live in illinois and want a measley 68000. please help as i want to get this thing on the road as soon as possible. you can email me at munent2@joimail.com or post it thanks a million Bob | ||
| FAST FRED (63.234.20.226) Rating: N/A |
8d's are what was expected to be able to start the coach after cold soaking all night. If you live or ONLY travel where it is always over 40F , tiny batts do work.. Down about ZERO F , its either a long running block heater or 8D's if you wish to move before the spring thaw. IF your back cant handle 8D's anymore 3 series 31 can replace each 8D. Remember new batts loose about 1% of there charge every day , so after sitting a month or more youre starting with 30 to 50% gone already. FAST FRED | ||
| DonTX/KS (66.82.9.31)
Rating: N/A |
Wrong Fred, the bus book for a 4905 only requires each battery have 900 CCA, and a good gp 31 will top out at over 1100 CCA(cold cranking amps). It NEVER says anything about an 8D, which has a very short life, excessive cost, and short warranty compared to the Gp 31. Two Gp 31s is all that is needed to start the big trucks in the cold and worked super on my 8V71, in fact MUCH better than the three sets of 8d's EVER did. | ||
| BrianMCI96A3 (65.160.215.64) Rating: N/A |
Fred has some strange ideas about batteries Stardust... We have had this battery discussion on the board numerous times. If you looked back in the archives you might be able to sample some of those discussions. The fact remains that TWO group 31's of adequate cranking amps are enough to do the job of starter battery for almost any situation you will run into. No fleets I have ever heard of run 6 group 31's, in most applications two or three group 31's are standard in virtually every OTHER industry that used DD two strokes for motive power. As I have mentioned before, with a smaller battery bank, you will need to monitor the batteries a little closer, and a good idea is to have float chargers on the batteries to maintain them, but the fact is our fleet of over three hundred trucks uses a pair of 31's (three group 31's in some)in all kinds of weather. In really cold weather, regardless of what batteries you are using, a block heater plugged in overnight when you know you want to start your bus in the morning is a really smart idea. Brian | ||
| DonTX/KS (66.82.9.32)
Rating: N/A |
UNLESS you are planning on using the bus as originally designed, meaning sitting inside the bus barn at night, engine off, and 49 people using reading lights. THEN go with the half dozen or so to support that load. Generally we are speaking here of converted buses. | ||
| DrivingMissLazy (66.168.175.51) Rating: N/A |
FF says "Remember new batts loose about 1% of there charge every day , so after sitting a month or more youre starting with 30 to 50% gone already. " Not so in my experience. My bus sat many times for six months up to a year, and as long as I did not have any old, tired or defective batteries, as some may have, I never had any indication of a significant loss of charge. Richard | ||
| DonTX/KSd (66.82.9.23)
Rating: N/A |
I think he must be referring to the 8d batteries, my group 31's never suffered from that 1% per day loss either. I DID notice he gave NO REFERENCE to the source of his statement. | ||
| Sam Sperbeck (204.248.119.254) Rating: N/A |
Hi Richard, I started my bus (GM 4106/ 8V71) today with two four year old group 31 batteries that have been sitting unused since October in the unheated area of my shop. It got up to over 80 degrees today so I didn't bother to plug in the block heater, but I still expected to have to charge the batteries. It fired right up without charging, with batteries that, in theory, should have been completely dead. Just lucky, I guess! Thanks, Sam Sperbeck | ||
| Jim-Bob (152.163.252.163) Rating: N/A |
Eagle uses 2 grp 31s which start the 8v92 just fine. I think GM's attachment to 8-ds started in the 40's & 50's and they just never changed. Nobody complains about having TOO MUCH battery, just not enough. | ||
| Nick Morris (Nick3751) (69.69.45.57)
Rating: N/A |
In my limited experince I can say that, and you'll have to translate this into useable info, with my 6-71, one 8d brand new will just do the trick in cold weather. I don't have a block heater installed but I didn't try to fire it up unless it was at least 40 for two days. I do keep a float charger on it and haven't had anytrouble since it's warmed up. It doesn't spin right over like my pickup(7.3 powerstroke) but after a third of a turn or so it starts spinning pretty good. I can also say that my truck will not crank it with jumpers going to the starter. I don't know how much battery is in it but it's what ever it's supposed to have. Just another bit of info. | ||
| Johnny (4.174.112.221) Rating: N/A |
With sub-zero temps, the 6V71 in the New Look at work lit off with no assist (not plugged in, no ether) after cold-soaking from 5pm Friday until 5:45am Monday. Batteries are 2 Group 31's. | ||
| Doug (68.83.23.33) Rating: N/A |
Not sure why this topic is discussed.....use whatever you want. keep in mind: Cranking amps and cold cranking amps as well as reserve power. an 8D will last just as long as a group 31. provided they are of equal qulaity and maintained properly. They will also degrade at the same rate. There is a specific reason why the huge room full of engineers at GM coach chose to use the 8D. and also good reasons why they are still produced in large quanities. Just because you can't stroll down to wallmart and get one is no reason not to use the appropriate battery in your coach. I can get an 8D battery just in any decent size town in a few hours for less around 120.00 for a high quality battery. My Last set of 8D's was purchased from a Battery shop in Ventura California 5 years ago and were delivered some 30 miles away for 120.00 each. They were even installed for that. they are still in perfect condition even with my extended non use ( 6 months at times with no starts) This winter I coould start my bus with no charge or engine heat down to around 32. It probably would have started colder with what I consider excessive cranking. My coach uses the coach batteries for Starting as well as all coach lights. the Fridge, all interior lights, hot water, water pump and microwave as well as the webasto airtop heater. I have dry camped for a week in temps in the 30's and 40's using the heater and hot water heaterevery day as well as interior lights and still was able to crank the engine to life without block heat, either or excessive cranking. I can also start my coach with one pickup abttery, not sure the group..... but with the conversion loads, coach loads it would not be sustainable. Running a stock 4104 heater blower will drain a brand new pair of 8D's to near dead in about 20-30 minutes with the engine off. not tooo mention if the defroster moater is used. Buy the batties you want, are comfortable with, can afford, and will do the job you need them to do. | ||
| BrianMCI96A3 (65.160.215.64) Rating: N/A |
Here we go again, with the room full of engineers argument. I work with engineers, and I know for a fact that a room full of engineers typing randomly, given an infinite number of hours, could type out War and Peace...Oh, no wait that's monkeys! I'm kidding of course, I know that engineers are people too, and being human sometimes their mistakes/designs leave a lot to be desired... Like the Flamming Pinto or the Vega with the silicon impreganted cylinder walls, or the Corvette that had to have the engine pulled to change the spark plugs. In the end you have to do as Doug suggests..."Buy the batties you want, are comfortable with, can afford, and will do the job you need them to do." Realizing.... that while Doug will be using his 8 D's as his house batts too, most of us will have a seperate house battery bank, and that group 31's are sufficient to the task of starter batteries for DD two strokes as well as a number of other large diesel engines under most, if not all conditions. Brian | ||
| FAST FRED (63.234.21.81) Rating: N/A |
The energy in a battery is detirmined by what the weight of the working lead is, period. A couple of lightweights can never perform as well as true heavyweights. LEAD is power and power is $$$ and power is weather you can get started on the 5th attempt to bleed the fuel system by the side of the road . Think of real batts as insurance from the unexpected. Dinky batts may work OK for some applications , but DA DD Book was written for ALL conditions . FAST FRED | ||
| FAST FRED (63.234.21.81) Rating: N/A |
For those who cant use the fine index, a reprint of my OPINION on batts, There is some confusion on the use of an 8D as a house battery. 8D is the size of the case the battery ,like 40R in a suit or 10EEE in shoes or "D" cell in flashlights. 8D is meaningless as to how the battery is constructed,, and its the guts, not the case size that detirmines the usage. Starting batts are like "Sears DieHards" made to deliver the max cold crank amps to your beast to get started in very cold weather. IF you live somwhere in "below freezing land", you will want TWO fully charged real starting batts to wake up that DD . RV MARINE are compromise batts that have a heavier construction than start batts.The plates are thicker and the space at the bottom of the plates is larger to accept chunks of slough off the plate surfaces. The plates are usually thin enough to give a fair starting voltage ,, and thick enough to be moderatly discharged, without early distruction. These are a great choice for the coach with NO house system,, that starts and overnites on one set of batts. They will die if cycled too deeply , no more than 40% down ,then recharge. REAL Deep Cycle batts can be discharged to the 50% or even 60% with only a small loss in service life. These if real deep cycle will have to be special ordered from a mfg. Surette or Trojan are two good brands. They will never be sitting at the local truck stop or K mart. Deep cycles will work very well as starting batts in a warm location , but dont have enough surface area to hold the voltage up in a zero day start. Whats the "best" system depends on the design of the coach systems. For boondockin I prefer real start batts and real deep cycle batts seperated with a simple charging relay ,, standard RV style. There are 200A relays ,,or 3 RV cheapos in parallel will do the job{relays should match alternator output}. For the Weekend Warrior a set of RV Marine "should do the job, particularly if a gen set and BIG {backside of a good inverter} charger is installed,, or if the coach lives with air cond and the batts live the easy life. Thje question of using a bunch of series 31 or the std. 8D is a matter of what your coach needs in the two most difficult conditions. First is starting in the real cold with OUT a block heater. IF Starting Amps is the key , batterys with loads of thin plates {like a Sears diehard } will work best , adding the cold crank amps will tell which is the winner. My big buck Marine Surette shows 31 with 700CCA and the Starting , NOT deep cycle 8D as 1130CCA Three ser31 are 59lbs times 3 for a weight of about 180 lbs. and 2100CCA Two 8D at 158 each is 320 lbs total and 2260 CCA. The batts would seem to be about equal for a short cold start , but if the batts were used at all to power the coach lighting or on a coach with NO house system the 8D would surely last lots longer. The extra lead is usefull only if you want to RUN dc loads from the set, and doesnt help the cold start , except the 8D will give more starting attempts before going dead. :" Ok, seems I've been misunderstood. I intend to dry camp for several weeks at a time. I understand from boat people that engine powered d/c chargers work excellent at charging batteries. How about this same unit on a bus? Hope thats clears up my question." You have to understand the RV folks are locked into reproducing what they saw years ago at some RV show. Therefore their only concept of a gen set is to run an air cond set or 2 or3 or 4 . If YOU need air cond , a big stinky gen set IS about the cheapest and easiest way to do that. A DC alternator does charge any battery bank better than a battery charger ,, ESPECIALLY if the batt set is of a really good size. IF you had 6 big batts rated at 225A , after a couple of deep cycles the batts will loose about 20% of there cycling ability , so 225 X 6 =1350A you paid for. With a 20% reduction ( assumes high quality batts } you will have about 1080A of rated capacity. AS youare deepcycling the bank lets say you go to the 60% charged reading on your E- meter {or with a temp compensating hydrometer}, the bank can be charged at a rate of C-15. This is 15%of the total batt capacity. 15% of 1080 is 162 AMPS or 15% of 1350 is 202AMPS , somwhere in there is the FASTEST charge rate that the bank will handle.{BULK charging } AS the acceptance rate will taper off as you get to the 90% full batts the charging rate will go down a bunch. Most folks get tired of the stink and noise and seldom charge over 95% , unless going down the road for many hours, or plug into a campsite. IF you will be having a really large bat set , and dont need air cond , a 200+ Amp gen set will produce the best charge for the batts , in the LEAST amount of time. FAST FRED A good 3 step regulator will keep track of the temp of the batts and let you charge well and quickly. The problem with doing this with a charger is two fold. There arent any 200A chargers that are sitting on the shelf , a great inverter , is a great charger too, but dont usually get yp to the 200+Amp area. The second hassle is that for some reason the inverters will not produce as many DC amps on a gen set , as they will on "shore" power. I do not know why.Somthing to do with peak voltage rather than RMS , but thats for somone else So if you really want to "anchor out" and live sans air cond , with a large set of batterys , and you want to keep the batt set working well for 10 to 12 years , YES a dc charging setup will work the best. BUT you will need a good 3 step voltage regulator , and a method of actually measuring whats left in the batt bank{E-meter or equal}. A Pulse Tech plate desulfator would be good insurance,too. The boat folks used to alternate between two sets of house batts, but today we know that ONE big set lasts longer,, although you need a seperate starting battery for the engine. The best House system would be 6 two volt cells wired in series for mega thousands of amps , if you could figure how to recharge , in a reasonable time. FAST FRED | ||
| DonTX/KS (66.82.9.82)
Rating: N/A |
Simple Math Problem: Fred, you say "Three ser31 are 59lbs times 3 for a weight of about 180 lbs. and 2100CCA" If you go back and read the posts, we have ONLY spoke of Gp 31 batteries with over 1100 CCA, which make two produce over 2200 CCA. (If I recall correctly, mine were 1160 CCA, making the total more like 2320 CCA). This beats the two you have in 8d size providing only 2260. Despite your idea that it won't work, those of us getting along perfectly well on 2320 CCA in cold weather will be hard to convince, even with your fuzzy logic. | ||
| Doug (68.83.23.33) Rating: N/A |
my lawst *D's were 1600CCA 3200CCA for the bank | ||
| bobm (68.35.160.48) Rating: N/A |
A good battery and charging solution is to add an 85 amp alternator to the engine that drives your generator and start your generator first when you think there will be a high demand on the cranking system. I also have a 45 amp alternator that I mounted in a frame run by a 5 hp briggs and straton as back up in case I run the coach batteries down | ||
| Nick Morris (Nick3751) (69.69.39.131)
Rating: N/A |
Just to clarify this in my fible little brain your speaking of a generator other than an Onan quite diesel right Bob? I haven't looked at one up close yet(although that's what I'm planning on useing) but I don't think there is a way to do that with a factory made genset, right? I sounds like a good idea if it would work with the gensets. | ||
| Geoff (Geoff) (66.238.120.119)
Rating: N/A |
Are we back on the argument of how many starting batteries we need??? Great! I say we need four Grp 31's to be adequately safe! --Geoff | ||
| DonTX/KS (66.82.9.79)
Rating: N/A |
HA! Geoff is a bettery dealer I bet. | ||
| DonTX/KS (66.82.9.79)
Rating: N/A |
Or a BATTERY dealer. | ||
| Curious (68.243.136.222) Rating: N/A |
As I understand it we need.... 42 starting batteries each weighing 150pds.. WE need 318 coach batteries to run at most one tv with inverter. The inverter needs to have 6 differenct stacking units.. This will allow us to run one tv but only if they dont produce square sine waves. Correct? | ||
| DonTX/KS (66.82.9.42)
Rating: N/A |
Yeah, that is adequately safe. | ||
| BrianMCI96A3 (65.160.215.64) Rating: N/A |
He He He you guys are damn funny! Brian | ||
| DonTX/KS (66.82.9.68)
Rating: N/A |
No. Just adequately safe. | ||
| Dale MC8 (66.81.133.38)
Rating: N/A |
Adequately funny ;-] | ||
| Phil Dumpster (24.16.243.37) Rating: N/A |
I use 8D batteries. My coach will start on the first try in 20 degree weather. I know as I have done it many times this past winter. It cranks vigorously and furiously. As long as this bus has an electric starter, I will probably also use 8D batteries. If I get the chance to convert over to an air starter, I may consider using group 31 or even group 27 batteries. You use small batteries at your own risk. If your bus won't start on a winter day with a pair of group 31s, you have only yourself to blame. Then again, if you never use your bus in such cold weather, I guess you don't have to worry about it. | ||
| TWO DOGS (63.185.96.134) Rating: N/A |
PHIL...air starter for sale on the "E" place | ||
| Johnny (4.174.67.60) Rating: N/A |
Phil, 2 healthy (~13 months old at the time) 31's will light off a 900,000-mile 6V71 in sub-zero weather with no assist. I did so several times last winter. The engine is in a transit, in daily passenger use. | ||
| DonTX/KS (66.82.9.79)
Rating: N/A |
Now Johnny, YOU know that, and I know that. Lets not confuse people with facts. | ||
| njt5150 (68.243.49.180) Rating: N/A |
I have air starter... I desire electric starter.. I am in Biloxi Ms. Lets make a deal... | ||
| Phil Dumpster (24.16.243.37) Rating: N/A |
Those are healthy ones cranking a normally aspirated series 71. Try that with a turbocharged series 92 in the same conditions. Group 31s might do it for a year, maybe two, but after that you're stranded. A pair of well-cared-for 8D batteries will do it every day of their 5 to 7 year service life with ease. njt5150, being that I'm in the pacific northwest I doubt it would be cost effective to ship an air starter plus the tank and plumbing. | ||
| njt5150 (68.243.144.96) Rating: N/A |
agreed.. Just meet me over here... WE will swap them out here.. | ||
| DonTX/KS (66.82.9.54)
Rating: N/A |
Phil, I cannot comment on 8V92 or your experience, but mine for an 8v71 was just the opposite. The darned 8D batteries cost me $150 each, $300 for two. The very BEST warranty I could find was less than a year, and THAT was pro rated, so you did not have much. I went thru three sets of them (they conveniently shot craps at the end of the warranty period just as planned by the manufacturer)in 5 years. I changed to Gp 31from NAPA, just about $200 for the pair, and a NON PRORATED warranty of 5 years! My thoughts at the time were, that they might not last any longer than the 8d, but at least I was not going to have to foot the bill. They are still in the bus, working like when new, they cranked the engine over far faster than the 8d's ever did. The test continures, they have been doing their job well for "only" 5 years now. It is important to point out, in my application, their purpose was ONLY to start the bus, not a bunch of extra duty, I used house batteries for that. | ||
| FAST FRED (63.234.23.14) Rating: N/A |
Don , My guess would be that you take good sized trips and run a charge V over 13.8. This will eventually boil the 8D's , where the seperate cases and thin starting plates of the 31 can stand overvoltage better. Ever measure the charge V at the end of a run? FAST FRED | ||
| DonTX/KS (66.82.9.46)
Rating: N/A |
Well you are partly right there Fred, since the 4905 was a 24V Bus, I ALWAYS ran charge over 13.8. (gotcha there :-) Charging voltage was always correct, at the time I had all the bad luck, I must confess that I abused them mostly from lack of use, short runs, discharge between runs, etc because the bus was being converted. The Gp 31's were installed at completion of the conversion, and with living in the bus, they still got mostly no use while parked to live in for the winter, or summer. I had a 24v automatic charger that I left on constantly, both with the 8d and the 31s. You are probably right in your assesment that the 31's take abuse better than 8d's do, at least it seemed that way to me.. It was not an original idea with me, I had enjoyed the Gp31's as a truck driver/owner for so many thousands of miles, starting BIG engines in the coldest of weather conditions, it merely seemed a natural thing to do since they far exceeded GMC Bus requirements. | ||
| John Rigby (65.112.227.94)
Rating: N/A |
Were is the best place to buy the 31,s and what is the best price?? My 8D,s have 36 months and are ready to change, before they let me down. John | ||
| TWO DOGS (63.185.81.18) Rating: N/A |
where ? measure the battery box & go to sams & get the bigest/heavyest one that will fit...or wal.mart... | ||
| DonTX/KS (66.82.9.29)
Rating: N/A |
Just have to shop I suppose, but when I was buying the NAPA store beat them all, longest warranty and best price, and freshest batteries.. | ||
| DonTX/KS (66.82.9.29)
Rating: N/A |
Just have to shop I suppose, but when I was buying the NAPA store beat them all, longest warranty and best price, and freshest batteries.. | ||
| Phil Dumpster (24.16.243.37) Rating: N/A |
If you are killing 8D batteries near their one year anniversary then you are abusing them or the brand you purchased was very low quality. Comparing low quality to high quality is not a fair comparison. I use Dyno brand batteries as they are made here in Seattle. Again, understand that turbocharged engines require more cranking to start than normally aspirated engines because of the lower compression ratio, and cranking the engine takes power. The smaller the battery, the deeper the discharge. Deep discharges kill starting batteries. If you start your bus in warm weather perhaps4 or 5 dozen times per year, then the smaller batteries will probably last as long as the typical car battery. In more frequent use and in lower temperatures, I wouldn't take the chance. | ||
| Johnny (4.174.103.85) Rating: N/A |
With daily cold-starts (the Fishbowl is rarely plugged in, & I don't use ether if avoidable), & anywhere from 2 to 10 hot starts over the course of the day, the 6V71 fires right up on 2 18-month-old 31's, even cold. I think they're Interstates. Get 2 good 31's, & you're fine. | ||
| BrianMCI96A3 (69.68.102.180) Rating: N/A |
I dispute the fact (as I did once before) that a turbo'd 8v92 engine takes any longer to start than a normally aspirated 8v71, we have had both in our fleet for years. Given two engines an 8V71 and an 8V92 in roughly the same condition, since a turbo'd engine has less compression, it may require a higher RPM to start... But the fact is, the starter actually will be under less load because of the lower compression. The 8V92 will spin up faster for a given current draw, thus will reach a higher rpm, and reach the point where the heat of compression will ignite the fuel/air mixture. In the real world, that means that the 8V92 engine will start and run at roughly the same time as a normally aspirated engine. Brian |