What is the difference between group 27 batteries and Group 31 batteries. I've read your guys thoughts on people switching to group 31's for bus starters. I have a Friend..of a friend, who has an uncle...etc, hat can get us group 27 batteries for next to nothing, as many as we wanted...so we told him we wanted 8! Will two of these 27's be good bus starters or will I need to use 4 to fire up my 8v71? We were going to tie the rest of the batteries in to the the house batteries.
There are a lot of threads here about batteries
You should check the voltage on each battery and be sure that they don't vary by more than a tenth of a volt. ( just what I have been told )
I have ruined a couple of batteries
If they are all about the same age and voltage then you can tie them together and they will work as a team
If they have different voltages and different ages then they will bug each other and one will try to be the boss and the if it wins then the other battery will quit working a go on welfare or something like that.
I hope this helps you
Melbo
Hi Greg,
There are alot of things you need to look at as Melbo has allready stated.
Free is Free but, will it serve you well in your bus?
Please read this information on batteries.
http://www.marine-electronics.net/techarticle/battery_faq/b_faq.htm#4
Good Luck
Nick-
Nick, that link is a great find. Thanks!
That link really needs to be added to the help section of the board. (or is it already there and I just missed it?)
Quote from: HighTechRedneck on April 15, 2008, 05:12:35 AM
Nick, that link is a great find. Thanks!
That link really needs to be added to the help section of the board. (or is it already there and I just missed it?)
Thanks,
It has been added to the Help section under Favorites and then Batteries here:
http://www.busconversions.com/bbs/index.php?topic=3071.msg39724#msg39724
Richard
That's what I was asking....will two group 27 batteries work to fire up a 8v71 religiously....without any troubles? Or will i need 4. Most guys say they have switched to 2 group 31's. Will the 27's with 30 less amps be enough power? Will they serve my house battery needs? I'll take that chance, plus a i have a genny, so that isn't my worry My start batteries are weak and i hoped that two of these babies would be sufficient. Anybody tried....anybody have a guess? 3 years ago, in my skoolie, we had 4 crown deep cells for our house batteries and I learned the hard way that when you park her for the the winters in Ohio, you best have a good charge in them, or they freeze, crack and they are not much good after that. We replaced them with 4 of these and they out lasted those crowns hands down, I would say lasted a day or so longer with out charging.
About the difference of group size...read this http://www.windsun.com/Batteries/Battery_FAQ.htm#Battery%20Size%20Codes
Look for "Battery Size Code"
Try to get at least 100 amps/hour rated version on either group. They come in many rating for any group number. The higher the "cold cranking" amps such as 970 CCA, the better. So look for your choice before you buy.
FWIW
Sojourn for Christ, Jerry
I have 2-size 31 Interstate flooded batteries for starting that are 950cca apiece-which I consider the lowest amperage you should have. The old 8D's would be 1200cca with more reserve power. But then again I can cheat, and activate the jumper solenoid between my two size 31 starting batteries and my two 8D AGM batteries (I have started the bus just on the deep cycles when the starting batteries went south). If you go with 27's (which are just a bit smaller than the 31's) I would have a means to be able to jump from the deep cycles-especially in cold weather. Remember-there is no such thing as having too many starting batteries-but your starter will be straining and possibly burn out with not enough starting amps. Good Luck, TomC
Thats what I was looking for. Do you have anymore information on this jumper solonoid? What it loks like, where i can get one, what it should cost, how to install?
The jumper solenoid looks like the old Ford starter solenoid you used to see on older Fords mounted on the inside fender by the battery. While it looks like it, it is built completely different. It is made for 150 amps continuous duty (I have left them activated for a week to charge the starting batteries off the inverter that's connected to the deep cycle batteries), and I have two of them in parallel to handle the 300 amp peak output of the alternator. I just simply made a heavy duty metal strap between the two and then attached the battery cable in between. It has worked flawlessly for 13 years that it has been in. I can't quite remember where I purchased them, but I would think any large auto supply (maybe even Camping World) would have them. I just like mechanical anything over electronic. Good Luck, TomC
I use the same solenoid set up for my genset start batteries
The solenoid is available at any RV supply house and as tom said they work flawlessly
Melbo
If you can get Group 27's for cheap use four 27's for starting and you will be fine. I wouldn't trust two.
Quote from: TomC on April 16, 2008, 04:54:06 AM
I just like mechanical anything over electronic.
That is absolutley the statement of one who has BTDT.
I totally agree. 8)
Cliff