Classic Winnebagos & Vintage RVs

Topic Boards => Coach => Topic started by: postman on December 20, 2017, 07:40 PM

Title: Deep Cycle 12V
Post by: postman on December 20, 2017, 07:40 PM
Just bought 2 Interstate SRM-27 off CL. Have fingers crossed as the seller said they were purchased new around June. I will check level, fill, and charge. I am old school and will check specific gravity. Wish me luck!
Title: Re: Deep Cycle 12V
Post by: Rickf1985 on December 20, 2017, 08:23 PM
Good luck, they are still a marine dual purpose battery and not a true deep cycle. They do appear to have a fairly good reserve capacity but I have never gotten the advertised amount out of a dual purpose. My next batteries are going to be true deep cycle. No starting rating at all.
Title: Re: Deep Cycle 12V
Post by: postman on December 20, 2017, 09:45 PM
Rick I have two maintenance free, however they have absolutely no markings & suspected (mexico). I took one to be tested and showed 850 amps. Now I have these SRM-27. I will configure them  parallel and take the best of the (mexico) batteries that I suspect were from Deka as chassis.
Title: Re: Deep Cycle 12V
Post by: Rickf1985 on December 21, 2017, 09:20 AM
Be careful running mismatched batteries in parallel, whichever one is lower will drag the other down and for some unknown reason it will go all the way down to dead in days. When if not hooked together they are fine. i?? i??  I have had that happen several times, I then take those batteries and put them in one of my military vehicles that are hooked in series and it does not affect them the same way since there is no physical connection between the two batteries. In series one is basically grounded to the other, strange way of putting it but it puts it in perspective that they are not really attached like they are in parallel where power is flowing back and forth between them.
Title: Re: Deep Cycle 12V
Post by: postman on December 21, 2017, 01:05 PM
My bad. My plan is the two SRM-27's in parallel for the house or coach whichever is proper. The Maintenance Free batteries, the strongest of the two will go to chassis.


Your description is accurate just expressed differently. I was taught it is because VDC  maximum amperes is always available in a circuit. I will have to look through my manuals for the fix. I remember it  was common in solar banks. 


At some point soon I want to inspect the two solar panels. Todo list keeps getting longer and the Honey-Do's demand priority.  :angel:
Title: Re: Deep Cycle 12V
Post by: postman on December 21, 2017, 05:17 PM
I found this diagram that supports you.


Note: terminal positions on opposite corners.  Hm?

(https://www.classicwinnebagos.com/forum/proxy.php?request=http%3A%2F%2Fhowdoinet.com%2Fwin%2F2x12VoltinParallel.gif&hash=dee84cbe93f1e0c5216ac6811d5efc6f4edb8a7a)
Title: Re: Deep Cycle 12V
Post by: Rickf1985 on December 21, 2017, 08:00 PM
Right, that is a parallel connection. But if one of those batteries is a bit weak it will draw down the good battery. That is why parallel batteries should always be replaced with a matched pair. Terminal position on the battery makes no difference.
Title: Re: Deep Cycle 12V
Post by: postman on December 21, 2017, 08:43 PM
my understanding is you draw (+) off one battery and (-) off the other. As in the diagram.
Title: Re: Deep Cycle 12V
Post by: DaveVA78Chieftain on December 21, 2017, 10:15 PM
Rick's point is
Forget how the batteries connect to the rest of the system.  If one battery is weaker than the other then the good battery will try to charge the weaker battery until both are discharged.  Has nothing to do with how you connect the batteries to the rest of the system.  HAs to do with different voltage potentials between the 2 batteries.
Title: Re: Deep Cycle 12V
Post by: postman on December 21, 2017, 11:24 PM
DaveVA78Chieftain,


Both SRM-27s are charging in parallel. I've seen disagreement on charging rate. So the Amp hour is 160 ea so in parallel that is 320. I opted to tickle charge @2amp. Tomorrow I will check the specific gravity.
Title: Re: Deep Cycle 12V
Post by: Froggy1936 on December 23, 2017, 02:54 PM
Please do be specific  W% Frank
Title: Re: Deep Cycle 12V
Post by: postman on December 23, 2017, 07:20 PM
???
Title: Re: Deep Cycle 12V
Post by: Rickf1985 on December 23, 2017, 08:47 PM
Ok, So if the batteries are 320 amp total and we will say they are at 75% that means they are now at 240 amp so you need to replenish 80 amps. At a 2 amp hour rate that will take 40 hours to recharge that 25%. BUT, If you have a newer 3 or 4 stage charger it would be much faster since they will charge the first 30-40 amps rather quickly and then drop down to around a 15 amp rate and taper to a trickle and then a maintenance charge. But in defense of the good old fashioned chargers like that 2 amp charger, I have put so called dead batteries on one and left it for a week and the battery has come back to life and lasted a good long time. It is not one that you want to leave plugged in all winter though.
Title: Re: Deep Cycle 12V
Post by: postman on December 23, 2017, 09:47 PM
Rickf1985,

Right now batts are charging 2amp in parallel. Because the charge is 2amp I will leave it tonight. Tomorrow I will charge them @2amp seperately.


Title: Re: Deep Cycle 12V
Post by: postman on December 26, 2017, 12:04 AM
After 24hr. rest, both batteries showed 12.76v which specs @ 95%. Maybe not brand spanky newie, but an upgrade to my Ahr X 2.  :)clap
Title: Re: Deep Cycle 12V
Post by: postman on January 07, 2018, 11:21 PM
The Battery tray is in for lack of a better term Battery Bay. Here's a pic of that wiring.

(https://www.classicwinnebagos.com/forum/proxy.php?request=http%3A%2F%2Fhowdoinet.com%2Fwin%2Fbattbay3.JPG&hash=382d6b2ef87ef67013cffbce36f397d65a4452c4)

Whats that wire do?  i??
Title: Re: Deep Cycle 12V
Post by: LJ-TJ on January 08, 2018, 08:11 AM
That's how my Battery Box started out and this is what I ended up with. Hm?
Title: Re: Deep Cycle 12V
Post by: Rickf1985 on January 08, 2018, 10:21 AM
Quote from: postman on January 07, 2018, 11:21 PM
The Battery tray is in for lack of a better term Battery Bay. Here's a pic of that wiring.

(https://www.classicwinnebagos.com/forum/proxy.php?request=http%3A%2F%2Fhowdoinet.com%2Fwin%2Fbattbay3.JPG&hash=382d6b2ef87ef67013cffbce36f397d65a4452c4)

Whats that wire do?  i??
I see voltage loss at just about every terminal in there! Yea, mine looked that way too. I think that area is a problem with just about all older units and it is usually overlooked as long as the lights even come on.
Title: Re: Deep Cycle 12V
Post by: LJ-TJ on January 08, 2018, 10:29 AM
 :)rotflmao Yeah no kidding. I keep waiting for someone to come up with a indoor alternative Hm? .
Title: Re: Deep Cycle 12V
Post by: postman on January 08, 2018, 06:43 PM
LJ-TJ,


That is a work of art compared to my copper spaghetti. Did you have a diagram or schematic to work from? I haven't found a single bit of useful info on my "House" circuits. it would save me days per circuit if you can help.
Title: Re: Deep Cycle 12V
Post by: tmsnyder on January 09, 2018, 01:27 PM

It does make a difference, hook it up as the diagram shows in, on positive of one battery and negative terminal of the other.  The reason is b/c the connections are never perfect, resistance is always >0 ohm.  (especially looking at the photos of your cables ! )  So you'll have a voltage drop at each connection once current starts to flow.  The dirtier the connection, the more the voltage drop for any given current.  You can and should clean them, it will help but it will never be perfect.   So if you connect the leads on one battery and parallel all the batteries after that off the first battery, the second battery will get less voltage than the first one, the third will get less then the second, and so on.  Taken to infinity, the last battery will get a charge voltage approaching 0V. 


If you wire as shown in your diagram, there may be voltage drop in the lines but at least both batteries are getting a similar charge, which is the goal.  You want them to be treated the same as each other so that they charge and discharge as one battery. 


Considering that these can be charged at 20, 50, 100 amps....  even a fraction of an ohm of resistance on the connections can result in significant charge voltage difference between the first and second battery if not wired as in the diagram.  So I wire them as in the diagram you posted.


Just this camper's view.

Quote from: postman on December 21, 2017, 08:43 PM
my understanding is you draw (+) off one battery and (-) off the other. As in the diagram.
Title: Re: Deep Cycle 12V
Post by: Winnebago Warrior 94 on January 09, 2018, 02:05 PM
My batteries in my rig was never hooked,up right ..it only had one battery in it so I need to use the diagram y'all have and hook up another battery up so I'm jave two batteries ..I also need to replace the terminal wires and beef up the battery holder as the older one is rusting through ..wouldnt be fun to loose my batteries when in driving down the road
Title: Re: Deep Cycle 12V
Post by: postman on January 09, 2018, 02:21 PM
I do wish I could find a "House" diagram. LJ-TJ's pic is great, but I have 4 reset breakers. Then I wonder, "Would Winnebago really wrapped up a bundle of wires like that?"  D:oH! 
Title: Re: Deep Cycle 12V
Post by: LJ-TJ on January 10, 2018, 05:48 AM
You would think it wouldn't make much scents for a company the size and caliber of Winnebago would approve that type of workmanship. But yep! I have five Winnebago's and all the battery compartments are the same. Hm?
Title: Re: Deep Cycle 12V
Post by: postman on January 10, 2018, 01:20 PM
Quote from: LJ-TJ on January 10, 2018, 05:48 AM
You would think it wouldn't make much scents for a company the size and caliber of Winnebago would approve that type of workmanship. But yep! I have five Winnebago's and all the battery compartments are the same. Hm?


LJ-TJ did you track, trace, and reverse engineer? Or. did you have a MAP! :) [size=78%] [/size]
Title: Re: Deep Cycle 12V
Post by: LJ-TJ on January 10, 2018, 03:43 PM
Well I know this is going to hurt BUT. I reversed engineered it. I even made a diagram for the lads to refer to. Unfortunately  D:oH! before I made a copy of it the motor home burnt to the ground.NUTS! It really isn't that hard to do. I just said the heck with it one day and on a hot day in the summer just laid on the ground and followed everything. I cut all the tape off everything so I could see were the wires went and then got plastic loom and black small tie raps and re-raped them. I still think there's a better way to do(locate) the battery compartment wires. Just haven't figure it out yet. 
Title: Re: Deep Cycle 12V
Post by: postman on January 10, 2018, 04:50 PM
Quote from: LJ-TJ on January 10, 2018, 03:43 PM
Well I know this is going to hurt BUT...  :(


Yeah, kinda saw that train comin... Being gravity is not my friend, I am going to have to employ technique. I am thinking I am gonna make the battery tray removable. I have already had to reconfigure the steering wheel so my feet can clear the dog house. Well at least you got a pic for posterior  :D




Title: Re: Deep Cycle 12V
Post by: Rickf1985 on January 10, 2018, 05:35 PM

One thing you can consider for battery to house connection are these Anderson connectors. This way your terminals on the battery stay connected and sealed and you can run the main wiring to wherever and just plug in the batteries at the source. The connector come in a wide range of sizes and are used for high amperage connections. If you are an old time R/C guy you might recognize them from the higher end battery connectors.

https://www.grainger.com/product/3BY21?cm_mmc=PPC:+Google+PLA&s_kwcid=AL!2966!3!166595346872!!!g!104635763397!&ef_id=V09pwwAAAaLJ9od7:20180110222536:s&kwid=productads-adid^166595346872-device^c-plaid^104635763397-sku^3BY21-adType^PLA
Title: Re: Deep Cycle 12V
Post by: postman on January 10, 2018, 09:49 PM
Quote from: Rickf1985 on January 10, 2018, 05:35 PM
One thing you can consider for battery to house connection are these Anderson connectors.


Rick gonna google that!
Title: Re: Deep Cycle 12V
Post by: Rickf1985 on January 11, 2018, 09:53 AM
They have them in bigger sizes because I remember them on forklifts I used to run and the cables were at least OO size cable.
Title: Re: Deep Cycle 12V
Post by: Winnebago Warrior 94 on February 09, 2018, 05:36 PM
Do y'all know if there is a diagram for hooking up 2 batteries ..the person I bought my rig from had just one battery in it ..they have wiring hooked up to solenoid to run just the,one battery ..in wanting to add another,battery and make sure all the wiring is hooked up like it should be ..I'd there a diagram that shows the wiring from batteries to solenoid and wiring leaving the batteries where it goes and what it should go to to make sure it is properly hooked up. Some of the smaller wires are disconnected and taped up..thanks 94 Winnebago warrior
Title: Re: Deep Cycle 12V
Post by: Rickf1985 on February 09, 2018, 05:52 PM
Go back to the 6'th post on this thread. positive to positive and negative to negative. then run your cables as normal, this is assuming you are using two 12 volt batteries. Dave has lots of diagrams on his site also. Are you talking about two batteries for just the coach or one for the coach and one for the chassis (engine)?
Title: Re: Deep Cycle 12V
Post by: Winnebago Warrior 94 on February 09, 2018, 09:54 PM
One for the coach and one for the engine and both batteries will be 12 volt..ill check,out the 6th post,..I saw the diagram ..I know positive go on the,solenoid and,I know the,negative go to the screw mounted to the frame ..but thesmaller,ones that charge the battery while you have pv plugged into electric ..do they go on the coach battery or does one wire go on one battery and one on thevotherv..thanks
Title: Re: Deep Cycle 12V
Post by: Rickf1985 on February 10, 2018, 09:43 AM
If you have one for each then they will not be connected together, they will be connected through a solenoid that can connect them if needed.
I tried to find the diagram Dave had on here but can't find it. I would PM Dave and ask for one of his diagrams and tell him you are looking to hook up both systems.
Title: Re: Deep Cycle 12V
Post by: Winnebago Warrior 94 on February 10, 2018, 10:49 AM
Thanks rick ..love the help and,dave is always great at getting things like that ..his little computer guy logo is spot on and you are always spot  on with the mechanics ..always appreciate yall