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06-03-2016, 12:44 AM
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#21
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Bus Geek
Join Date: Mar 2011
Location: Houston, Texas
Posts: 8,462
Year: 1946
Coachwork: Chevrolet/Wayne
Chassis: 1- 1/2 ton
Engine: Cummins 4BT
Rated Cap: 15
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Add spark...go Kablooey!!!
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06-05-2016, 11:27 AM
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#22
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Bus Geek
Join Date: May 2009
Location: Columbus Ohio
Posts: 19,897
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
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so help me out some more on this gassing thing...
if i understand this right the only time batteries off-gas is being charged,,,
so for me the only time is when my bus is running... isnt there enough air leakage and such in a school bus that using an AGM battery wont off-gas??
so then I read about these batteries called VRLA ..
im REALLY confused aboutthis whole thing...
I really just wanted to stuff a couple 8D batteries into a cabinet out of sight.. hook them up through an isolater so my fantastic 200 AMP alternator could charge them up when my bus is running.. and not kill my starting cells when the bus is off..
but off-gassing, AGM, VRLA... red top blue top yellow top.. all has me more confused than ever...
if a battery is supposedly sealed but yet off gasses doesnt that mean that battery is killing itself? if I cannot replace the water and it gives off gas seems like that battery is just being ruined quickly.. therefore does a sealed battery not off-gas?
if an alternator in a bus or car constantly charges a battery.. and therefore theorrtically over-charges since it charges 100% when the vehicle is on.. how are my maintenance free car batteries lasting close to 10 years? wouldnt they gas away all of their water and be dead?
-Christopher
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06-05-2016, 11:56 AM
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#23
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Bus Crazy
Join Date: May 2010
Location: Farmington Hills, Mi (Detroit area)
Posts: 1,968
Year: 2000
Coachwork: Eldorado Aerotech 24'
Chassis: Ford E-450 Cutaway Bus
Engine: 7.3L Powerstroke
Rated Cap: 19
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Quote:
Originally Posted by cadillackid
if an alternator in a bus or car constantly charges a battery.. and therefore theorrtically over-charges since it charges 100% when the vehicle is on.. how are my maintenance free car batteries lasting close to 10 years? wouldnt they gas away all of their water and be dead?
-Christopher
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Each alternator has a regulator that senses how much amperage the system requires then energizes enough windings to meet the need. You'll see the voltage output change a few tenths of a volt but it's the variable amperage that charges (and protects) the battery. As your batteries charge, the regulator adjusts the amperage down so it doesn't boil the cells dry. As long as the regulator is doing it's job there shouldn't be a problem. The vented enclosure is there for the times when things go sideways.
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06-05-2016, 01:14 PM
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#24
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Bus Geek
Join Date: May 2009
Location: Columbus Ohio
Posts: 19,897
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
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makes sense.. the alternator does drop the voltage the longer it runs .. starts out at close to 14 volts then drops to 13....
so on a normal basis an AGM battery doesnt outgas?.. only if my regulator decided to just rip it a new one.... at which time id see my voltage gauge up at 15 or higher...
how does a VRLA battery work?
or I simply need to place a relay on the battery that monitors voltage and charge current from the alternator going to that battery to know its charged and turn it off?
-Christopher
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06-05-2016, 03:02 PM
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#25
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Bus Crazy
Join Date: Nov 2010
Location: Andrews,Indiana
Posts: 2,458
Year: 1991
Coachwork: Bluebird
Chassis: AARE
Engine: 3116 Cat 250hp
Rated Cap: Just the two of us.
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Explanation of battery types.
https://en.wikipedia.org/wiki/VRLA_battery
All batteries have a vent, they have to.
Quote:
VRLA batteries have a pressure relief valve which will activate when the battery starts building pressure of hydrogen gas, generally a result of being recharged
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Also any battery with a bad cell will act like it is being overcharged on that cell, and because the voltage isn't right on the entire battery the voltage regulator will try to charge it harder. It's a vicious circle.
I once mounted some batteries in an indoor cabinet, it was pretty simple to enclose them and vent to the outside. I used a number of the little 1 inch vents made to vent siding. Like these
Round Screened Vent, 1", Pack of 6 - Walmart.com
That trailer is still here, if you need pics I can get them later.
Dick
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06-05-2016, 03:14 PM
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#26
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Bus Geek
Join Date: May 2009
Location: Columbus Ohio
Posts: 19,897
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
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since I only charge when im runniung the bus what if i just had a little fan that blew the air from the battery compartment of VRLA AGM batteries into the bus itself? seems like theres enough air leakage into a school bus being driven that Hydrogen isnt going to build up to a concentration to explode or smell bad.. if I did smell something id know i have a dead cell perhaps..
im just trying not to drill holes in the side of my bus that will let in and out the hot and esp cold air.. I could see the need for outside holes if I was charging from shore power and the bus was parked where i would have very little air infiltration from the normal bus methods like defroster intakes, leaky windows, etc
-Christopher
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06-05-2016, 04:37 PM
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#27
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Bus Crazy
Join Date: Nov 2010
Location: Andrews,Indiana
Posts: 2,458
Year: 1991
Coachwork: Bluebird
Chassis: AARE
Engine: 3116 Cat 250hp
Rated Cap: Just the two of us.
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If you seal off a compartment,and vent to the outside, how is precious cool or warm air going to get away?
You can do whatever you want, there aren't any "skoolie" police.
Dick
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06-06-2016, 08:13 AM
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#28
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Bus Geek
Join Date: May 2009
Location: Columbus Ohio
Posts: 19,897
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
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Quote:
Originally Posted by somewhereinusa
If you seal off a compartment,and vent to the outside, how is precious cool or warm air going to get away?
You can do whatever you want, there aren't any "skoolie" police.
Dick
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if there were skoolie police id already be in Jail since I left most of the seats in the bus and didnt tear down my ceiling
im just tryign to get answers to 2 questions..
1. AGM VRLA batteries - if you never put water in them.. how can they off gas enough to cause issues and not be "dried up" within a short time.
2. AGM VRLA batteries - if they in fact outgas because my alternator decides to go rogue and push out 16 volts.. is enough gas produced to fill up the inside of a moving school bus that would either cause me to pass out or cause a fire, assuming the compartment is vented to the interior of the bus...
3. Standard Lead Acid batteries - I do understand that they boil when charged and have seen iot / smelled it when a car bnattery is put on a charger that has no management solution... so these type batteries are OUT for me unless i magically learn how to weld a battery compartment into my bus soon...
I really just want to be warm / cool / dry and not Blow up or die from some wierd gas..
-Christopher
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06-06-2016, 12:30 PM
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#29
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Bus Crazy
Join Date: Nov 2010
Location: Andrews,Indiana
Posts: 2,458
Year: 1991
Coachwork: Bluebird
Chassis: AARE
Engine: 3116 Cat 250hp
Rated Cap: Just the two of us.
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They are still lead acid batteries.
From the WIKI article I supplied a link to.
Quote:
Lead-acid cells consist of two plates of lead, which serve as electrodes, suspended in diluted sulfuric acid, which is then the electrolyte. In conventional lead-acid cells, the diluted acid is in liquid form, hence the term "flooded" or "wet" cells. VRLA cells have essentially the same lead-acid chemistry, but the diluted acid electrolyte solution is immobilized, either by soaking a fiberglass mat in it (hence: glass-mat batteries), or by turning the liquid into a paste-like gel by the addition of silica and other gelling agents (hence: gel batteries).
When a cell discharges, the lead and diluted acid undergo a chemical reaction that produces lead sulfate and water . When a cell is subsequently charged, the lead sulfate and water are turned back into lead and acid. In all lead-acid battery designs, charge current must be adjusted to match the ability of the battery to absorb the energy. If the charging current is too great, some of it will be wasted decomposing water into hydrogen and oxygen, in addition to the intended conversion of lead sulphate and water into lead dioxide, lead, and sulphuric acid which reverses the discharge process. If these gases are allowed to escape, as in a conventional flooded cell, the battery may need to be topped up with water from time to time. In contrast, in VRLA batteries the gases are retained within the battery as long as the pressure remains within safe levels. Under normal operating conditions the gases can then recombine within the battery itself, sometimes with the help of a catalyst, and no topping-up is needed. However, if the pressure exceeds safety limits, safety valves open to allow the excess gases to escape, and in doing so regulate the pressure back to safe levels (hence "valve-regulated" in "VRLA").
In flooded lead-acid batteries, the liquid electrolyte is a hazard during shipping and makes them unsuitable for many portable applications. Furthermore, the need to maintain water levels makes them unsuitable for maintenance-free applications. The immobilized electrolyte in VRLA batteries addresses these problems. At the same time, since VRLA cells can't be "topped off" with water, any hydrogen lost during outgassing can't easily be replaced. To some extent, this can be compensated for by overprovisioning the quantity of electrolyte, but at the cost of increased weight. The main downside to the VRLA design is that the immobilizing agent also impedes the chemical reactions that generate current. For this reason, VRLAs have lower peak power ratings than conventional designs. This makes them less useful for roles like car starting batteries where usage patterns are brief high-current pulses (during starting) followed by long slow recharging cycles. VRLAs are mostly found in roles where the charge/recharge cycles are slower, such as power storage applications.
Both flooded and VRLA designs require suitable ventilation around the batteries; both to prevent hydrogen concentrations from building up (hydrogen gas is highly flammable, and is an asphyxiant), and to ensure that the batteries receive adequate cooling.
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Quote:
if they in fact outgas because my alternator decides to go rogue and push out 16 volts
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Probably not likely, alternator/regulators are more likely to undercharge or not charge at all. I would be more concerned about this,
Any battery with a bad cell will act like it is being overcharged on that cell, and because the voltage isn't right on the entire battery the voltage regulator will try to charge it harder. It's a vicious circle.
The compartment does not have to be welded up out of metal. Furnace ducting or wood as long as it's sealed would do fine.
Dick
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06-06-2016, 07:02 PM
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#30
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Bus Geek
Join Date: May 2009
Location: Columbus Ohio
Posts: 19,897
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
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good stuff!!! for some reason the link didnt work for me previously.. not sure why..
anyway its a great read..
I also talked to someone that made a great point.. his idea is this..
1. my batteries are House batteries, not starting batteries so building a box fits under the bus doesnt mean the skirting has to be cut and a fancy door installed.. a battery box with vents can be bought.. and then easily hung and tucked up under a Bus.. so theres no access.. you typically dont have to touch the house batteries.. install AGM VRLA so never have to water them..
the box can be lifted up and down by a floor jack with a platform.. (ie my transmission jack..)..
a box is easily hung without needing to weld.. it would have through-bolts and either large wasgers / plates into the bus floor... and those bolt holes are easily sealed.. hardware can be stainless steel and / or treated with grease / jelly, etc during maint intervals to keep the bolts from rusting into a mess..
run the wires from the box to a terminal block inside the bus... and thats where the parallel connection occurs, the isolator is located, as well as the connection to the alternator.. circuit breakers or fuse links install at this location as well..
thus if or when a battery goes bad or needs to be disconnected it doesnt require access to the battery box / boxes immediately as that can be done inside the bus.. and then such time when the bus is home the battery box could be lowered and the battery replaced or serviced / etc...
it could be years between times that box has to be lowered if good quality AGM VRLA batteries are used.. and esp if an isolator used is also a charge manager that keeps the charge always more than 20% and controls overcharging..
what you think? is this viable? or do batteries have to be touched more often than he thinks they do?
-Christopher
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06-06-2016, 08:06 PM
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#31
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Bus Crazy
Join Date: May 2010
Location: Farmington Hills, Mi (Detroit area)
Posts: 1,968
Year: 2000
Coachwork: Eldorado Aerotech 24'
Chassis: Ford E-450 Cutaway Bus
Engine: 7.3L Powerstroke
Rated Cap: 19
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If you'll be camping in cold temps your batteries will give you more power if they are warm inside the bus.
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06-06-2016, 08:10 PM
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#32
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Bus Geek
Join Date: May 2009
Location: Columbus Ohio
Posts: 19,897
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
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I'll only be stopping for a couple hours at a time max.. ill be able to get some engine heat if I turn the bus off and run the booster pump with just the rear heater fan... otherwise for heat I'll run the bus or maybe install a webasto coolant line heater so I dont have to run the bus...
main thing will be running my electric A/C when the bus is shut down and thats in warm temps.. the cases ive been seeing dont seem to have a concentrated vent.. I need to look harder and see if I can find a truly sealed case that has just a single vent that I could run out of the bus if I want them inside...
if im drawing a decent load from them in cold weather I should be able to keep them warm also..
-Christopher
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06-07-2016, 07:27 AM
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#33
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Bus Crazy
Join Date: Nov 2010
Location: Andrews,Indiana
Posts: 2,458
Year: 1991
Coachwork: Bluebird
Chassis: AARE
Engine: 3116 Cat 250hp
Rated Cap: Just the two of us.
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Quote:
1. my batteries are House batteries, not starting batteries so building a box fits under the bus doesnt mean the skirting has to be cut and a fancy door installed.. a battery box with vents can be bought.. and then easily hung and tucked up under a Bus.. so theres no access.. you typically dont have to touch the house batteries.. install AGM VRLA so never have to water them..
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I thought about suggesting this, didn't know if you would go for it. You wouldn't really need a box, just a frame to hold them, venting would take care of itself.
Quote:
hardware can be stainless steel and / or treated with grease / jelly
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Stainless isn't as strong as steel, use antisieze on them
Quote:
run the wires from the box to a terminal block inside the bus.
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Use something like this to avoid any problems with air/critters
http://www.summitracing.com/parts/mor-74144?seid=srese1&gclid=CjwKEAjw4dm6BRCQhtzl6Z6N4i 0SJADFPu1nDRhecA3zDjuXEGooQieTncU2Rei3zS_Wkj1gOw8B bxoChxXw_wcB
Quote:
it could be years between times that box has to be lowered if good quality AGM VRLA batteries are used
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I would think that you would at least need to clean the terminals once a year. The VLRA don't corrode like regular batteries because there is basically no vapors coming from them, but the terminals are lead and need an occasional cleaning.
Quote:
is this viable? or do batteries have to be touched more often than he thinks they do?
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yes and yes
Dick
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06-07-2016, 07:43 AM
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#34
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Bus Geek
Join Date: May 2009
Location: Columbus Ohio
Posts: 19,897
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
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Good idea on those thru-wall connectors.. I had forgotten about those!..
I was thinking the batteries would need to be in some type of box just to keep the salt and road water from splashing up on them... some of that junk has to be somewhat conductive / corrosive...
my bus is Driven more than it is parked when i have it out...
im waiting for a friend that works in a car audio shop to look at their battery boxes.. he thinks he has a couple styles that have a concentrated 1 inch vent which are otherwise sealed.. so I could vent from inside the bus if I chose... does mean a hole in the wall but if the box is truly sealed i wont lose my heat / cold ...
then again I could just add more heaters / Air conditioners
-Christopher
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06-07-2016, 11:55 AM
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#35
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Bus Crazy
Join Date: Feb 2012
Location: Salt Lake City Utah
Posts: 1,635
Year: 2000
Chassis: Blue Bird
Engine: ISC 8.3
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Quote:
Originally Posted by cadillackid
im just trying not to drill holes in the side of my bus that will let in and out the hot and esp cold air..
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Quote:
Originally Posted by cadillackid
does mean a hole in the wall but if the box is truly sealed i wont lose my heat / cold ...
then again I could just add more heaters / Air conditioners
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I'm kind of chuckling to myself and hoping it's okay to tease a little bit.. we're getting all this concern about battery box air leaks from the guy who wants to leave the side emergency exit door wide open and work at a desk just inside it with the A/C running, and has enough A/C capacity to run a mobile freeze dry service. (I guess the air leaks would present a problem when commissioning the vacuum part of the freeze dry operation!)
I do have something helpful to add, too. Batteries in a rack under the body might be relatively well-protected with just side shrouds clipped on after the batteries are loaded into their rack. There often isn't a great deal of protection provided to batteries living in the engine compartment after all. Yes there could accumulate "stuff" on the battery surface and provide a leakage path between the battery terminals, but I'd think that would really become noticeable only if the vehicle sat unused in storage with no charge source for a time. With regular use the leakage will probably be small compared to the demands of actual use.
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06-07-2016, 05:02 PM
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#36
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Bus Nut
Join Date: Feb 2015
Location: North carolina
Posts: 651
Year: 1986
Coachwork: Thomas
Chassis: Ford
Engine: Detroit 8.2
Rated Cap: 60 bodies
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Quote:
Originally Posted by family wagon
I'm kind of chuckling to myself and hoping it's okay to tease a little bit.. we're getting all this concern about battery box air leaks from the guy who wants to leave the side emergency exit door wide open and work at a desk just inside it with the A/C running, and has enough A/C capacity to run a mobile freeze dry service. (I guess the air leaks would present a problem when commissioning the vacuum part of the freeze dry operation!)
I do have something helpful to add, too. Batteries in a rack under the body might be relatively well-protected with just side shrouds clipped on after the batteries are loaded into their rack. There often isn't a great deal of protection provided to batteries living in the engine compartment after all. Yes there could accumulate "stuff" on the battery surface and provide a leakage path between the battery terminals, but I'd think that would really become noticeable only if the vehicle sat unused in storage with no charge source for a time. With regular use the leakage will probably be small compared to the demands of actual use.
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Way more than I was going to suggest.
I was going to say build a battery compartment underside with an un-sealed access door and the venting will take care of its self.
My starting batteries are on a crude slide out but it works when needed.
My house batteries will be underside in a storage compartment and if I think I need more ventilation then I will drill holes in the entering air side add some copper screen and drill some holes in the leaving air side and cover with some screen.
You can over engineer anything and spend a lot of money and time creating what you want or you/we can use the older tried and true methods?
You don't want any battery good or bad off gassing in your breathable space?
Put them underneath and let natural ventilation help even if you want to add a louvre's to your design.
Batteries in use create heat even in cold weather.
Batteries setting dormant in cold weather do seem to lose charge faster but not if they are used daily.
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06-07-2016, 07:09 PM
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#37
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Bus Geek
Join Date: May 2009
Location: Columbus Ohio
Posts: 19,897
Year: 1991
Coachwork: Carpenter
Chassis: International 3800
Engine: DTA360 / MT643
Rated Cap: 7 Row Handicap
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I think underneath is what im leaning towards.. just trying to not have to cut my skirting.. I dont have the tools or skills to fab up a slide and a door.. thats why i was leaning towards something i could raise and lower only as needed.. its easy to bolt something together and then bolt through floor for support... not as easy to cut out the skirt, make a door, and a frame and slide..
I looked at the original slide.. the one that houses the starting batteries and that is pretty crude.. but still has a tray and skirt access.. doesnt look like much water gets in.. but a little does get in and doesnt seem to hurt anything..
I know im all over the place on this.. just limited on what I can do unless I want to go buy very expensive tools i'll only use once ..to weld, cut and bend sheet metal properly, etc.. since im not doing a full conversion, such tools wont be useful to me for the whole project like if I was skinning a bus or doing a riase or such..
-Christopher
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06-10-2016, 07:29 PM
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#38
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Bus Nut
Join Date: May 2016
Location: Richmond Virginia
Posts: 932
Year: 1984
Engine: 366 Big block Chevy! :) w/ Stick shift
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Nationwide golf Cart ! 5519 Mechanicsville Turnpike. Mechanicsville VA.
I just bought two Trojan t105 for a superb price!
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06-10-2016, 08:41 PM
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#39
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Skoolie
Join Date: Feb 2016
Location: East Coast kid
Posts: 142
Year: 1995
Coachwork: Bluebird
Chassis: International 3800
Engine: T444e
Rated Cap: 66
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Alright, so I'm looking to go the AGM route for my solar power setup... and I've seen several skoolers that put their battery bank inside the cabin. I would like to do the same. How much (or little) do the AGM batteries need to be sealed/ventilated? Just some piping and a vent? ...or a fan too? Just a lidded box?
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06-10-2016, 09:21 PM
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#40
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Bus Nut
Join Date: Mar 2015
Location: hills of sw virginia
Posts: 889
Year: 1996
Chassis: thomas
Engine: 8.3 cummins
Rated Cap: 11 window
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