janan5243 Posted October 15, 2015 Author Report Share Posted October 15, 2015 This problem is getting weirder. Checked all circuits again. Everything wired as should be. All voltages are correct. As I stated earlier in post, I have a hybrid battery set up. 2 6V batteries in series. First battery powers all original circuits at 6v. Second battery provides 12V for modern conveniences. Applied 6V to starter solenoid to activate starter directly from 6V battery, nothing. Just for s**ts & giggles, decided to apply 12V to same post. Eureka, solenoid activates starter & starter turns engine over. Turn key on & engine starts. Alternator works. If anyone here has a clue as to what the hay is going on, please, please chime in. Quote Link to comment Share on other sites More sharing options...
Niel Hoback Posted October 15, 2015 Report Share Posted October 15, 2015 Evil spirits. Quote Link to comment Share on other sites More sharing options...
DonaldSmith Posted October 15, 2015 Report Share Posted October 15, 2015 (edited) Here is a diagram of my 6-volt batteries in series, sort of like house wiring, with 110 volts from either hot wire to the neutral wire. Across the two hot wires you get 220, 221, whatever it takes. The main battery powers the 6-volt stuff, including the starter. The 6-volt, positive ground alternator recharges the main battery. The accessory battery is negative ground. I get 12 volts from its positive post and the main battery's negative post. I have to manually recharge the accessory battery from time to time. See how this compares with your setup. Edited October 15, 2015 by DonaldSmith Quote Link to comment Share on other sites More sharing options...
mopar_earl Posted October 15, 2015 Report Share Posted October 15, 2015 (edited) Here is a diagram of my 6-volt batteries in series, sort of like house wiring, with 110 volts from either hot wire to the neutral wire. Across the two hot wires you get 220, 221, whatever it takes. The main battery powers the 6-volt stuff, including the starter. The 6-volt, positive ground alternator recharges the main battery. The accessory battery is negative ground. I get 12 volts from its positive post and the main battery's negative post. I have to manually recharge the accessory battery from time to time. See how this compares with your setup. DSCF5129.JPG You could do that with a 12v pos ground alternator and charge both batteries and have 12v pos and neg ground to pick from provided your 12v items aren't body grounded as in has a power and ground wire. This would keep the car 6v pos ground. Or you could change the car to neg ground and use a 12v neg ground alternator and the car would be 6v neg ground.Earl Edited October 15, 2015 by mopar_earl Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted October 15, 2015 Report Share Posted October 15, 2015 It is possible to have 2 separate systems, one 6 volt positive ground, one 12 volt negative ground. This requires a separate charging system for each voltage. Quote Link to comment Share on other sites More sharing options...
janan5243 Posted October 15, 2015 Author Report Share Posted October 15, 2015 (edited) Donald; as Earl mentioned, you have to make sure 12V stuff either doesn't care about + or - grd., or keep the 12V ground isolated from the 6V grd. Last year in another post, I talked about this & I believe Plymouthy brought up the subject of grounds. I converted to neg. grd & that started my problem because I didn't consider the regulator grd. Regulator malfunctioned & didn't regulate generator, allowing it to produce almost 10V, burning out some bulbs. I don't think it affected anything else. I too have put 6V alternator in to charge main battery. Earl; I was going to use 12V alternator but was advised by several people in auto electric industry that the alternator would not charge both batteries equally since they would see different loads & the alternator would not see that. So the way that I & some others have chosen to get 6V & 12V in there cars means that you either charge second battery occasionally or also add a 12V alternator & the two alternators would keep everything charged. That is what I am going to attempt over the winter because I have a 12V HEI ignition I want to install & I don't believe the second battery would hold up too long with that kind of load. Donald; after looking over your schematic again, I don't see how you get 12V from that. You show the negative post of one battery connected to the Positive side of the other battery & use the connection as 12V. To get 12V with 2 batteries in series, you connect the positive of one to the negative of the other & the remaining negative & positive posts gives you 12V. Don. you are correct but as stated above you have to isolate both systems. you cant use a common grd. Edited October 15, 2015 by janan5243 Quote Link to comment Share on other sites More sharing options...
mopar_earl Posted October 15, 2015 Report Share Posted October 15, 2015 It is possible to have 2 separate systems, one 6 volt positive ground, one 12 volt negative ground. This requires a separate charging system for each voltage. Can do it with just one 12v pos ground alternator and two 6v batteries. Car would remain 6v pos ground and I'd have both 12v neg and pos ground to use. I plan to do this with my car. That way I can run a 12v neg ground items such as GPS, cell chargers, cooling fans, ac, etc. Anything that isn't case grounded. I can draw a diagram but I can't seem to upload pics to the forum or its different than I'm use to. Earl Quote Link to comment Share on other sites More sharing options...
mopar_earl Posted October 15, 2015 Report Share Posted October 15, 2015 The batteries would equalize when charged. No need for two alternators. Same thing when you use a battery isolator. Voltage much like fluid will equalize. In my system the batteries are in series to make 12v for the alternator and 12v loads. A single battery provides the 6v. Been done forever in all kinds of equipment with 6v, 12v, 24v and 48v. My camper has two 6v batteries in series for 12v. They charge just fine on a 12v converter/charger. Voltage will always equalize. Earl Quote Link to comment Share on other sites More sharing options...
Merle Coggins Posted October 15, 2015 Report Share Posted October 15, 2015 The batteries would equalize when charged. No need for two alternators. Same thing when you use a battery isolator. Voltage much like fluid will equalize. In my system the batteries are in series to make 12v for the alternator and 12v loads. A single battery provides the 6v. Been done forever in all kinds of equipment with 6v, 12v, 24v and 48v. My camper has two 6v batteries in series for 12v. They charge just fine on a 12v converter/charger. Voltage will always equalize. Earl Not entirely true. I've seen several cases on 24 volt equipment (2-12 volt batteries in series) where someone tapped off one battery to power a 12 volt radio. Everything would work fine, but the other battery will almost always fail prematurely. It seems that the battery that isn't being used for the 12 volt accessories will get over charged and have a shorter life. I've worked with other machines that use a mix of 24 volt and 12 volt systems that use a Battery Equalizer to ensure equal charging to both batteries. Merle Quote Link to comment Share on other sites More sharing options...
mopar_earl Posted October 15, 2015 Report Share Posted October 15, 2015 If that's the case, how do batteries in parallel not have the same issue? My diesel truck batteries are 9 years old and are fine. They take different loads off each battery so neither one is loaded the same. How do these batteries stay equalized? Earl Quote Link to comment Share on other sites More sharing options...
mopar_earl Posted October 15, 2015 Report Share Posted October 15, 2015 (edited) I do plan to run the 6v/12v system with a single alternator. I have full confidence it will work correctly. Won't be any time soon but I will advise my findings when I do it. Another point. How about those 6/12 volt combined batteries for antique cars. Same thing, just done internal the battery. Earl Edited October 15, 2015 by mopar_earl Quote Link to comment Share on other sites More sharing options...
Merle Coggins Posted October 15, 2015 Report Share Posted October 15, 2015 If that's the case, how do batteries in parallel not have the same issue? My diesel truck batteries are 9 years old and are fine. They take different loads off each battery so neither one is loaded the same. How do these batteries stay equalized? Earl When the batteries are connected in parallel they will share the load equally. Even if you connect something to the terminal on one battery you are essentially connected to both through the connecting battery cable, so you are pulling load from both batteries at the same time. But even with this system it is very important to replace the batteries as a pair with equal Ah rated batteries. If you were to replace one battery and keep one old battery, or use one 1000 Ah battery and one 750 Ah battery you will find that they won't share the load equally and one will have a shorter life. Just relaying my experiences. I don't claim to be an expert on this. Merle Quote Link to comment Share on other sites More sharing options...
mopar_earl Posted October 15, 2015 Report Share Posted October 15, 2015 When the batteries are connected in parallel they will share the load equally. Even if you connect something to the terminal on one battery you are essentially connected to both through the connecting battery cable, so you are pulling load from both batteries at the same time. But even with this system it is very important to replace the batteries as a pair with equal Ah rated batteries. If you were to replace one battery and keep one old battery, or use one 1000 Ah battery and one 750 Ah battery you will find that they won't share the load equally and one will have a shorter life. Just relaying my experiences. I don't claim to be an expert on this. Merle I'm no expert either. I've had several battery courses and it was never mention it would be a problem. Using a battery isolator would be the same thing and thy seem to hold up. I could be wrong but in my mind it should work. Even in the system I plan to use, both batteries are connected together and should equalize on draw as well as charge when with different loads. Granted one battery might lag behind the other but they should become equal in short time. But I will try this and see. Should work just like one of those 12/6 volt batteries. Id use obe of those but i want dry cell batteries. Earl Quote Link to comment Share on other sites More sharing options...
janan5243 Posted October 15, 2015 Author Report Share Posted October 15, 2015 Earl; I also have a diesel truck with 2 batteries in parallel. The load is equal on the batteries because the system sees them as one battery as does the alternator. In a series circuit, I don't know why the batteries won't charge equally but 4 people in the auto electric industry have told me that when one battery has a larger load on it, as my first battery does, that battery will ultimately go dead. I also wondered about the 12V antique car battery with a 6v post in the center. They do say that you have to have a 12V charging system. I didn't go that route because I thought it would be more expensive but with the cost of two batteries & two alternators, plus the fabrication involved, it would have been a little cheaper with a lot less fabrication involved. My total will be about $450 the way I'm going. With the single battery & alternator, it would be about $ 375. I had a double pulley put on the alternator so I could hopefully run the second alternator off it. Doing that allowed me to use stock bracket with a threaded rod to mount alternator. Quote Link to comment Share on other sites More sharing options...
mopar_earl Posted October 15, 2015 Report Share Posted October 15, 2015 I'm no battery wize but I want to try it. I remember one electrical class I had was series parallel switches. This allowed early semis to start with 24v and have 12v for the cab. I can't recall anymore how it all worked. I've worked on and installed battery isolators and they hold up fine. It isolates one battery system from another but both charge off one alternator. Like a motorhome. Chassis batteries and the coach batteries are isolated with completely different loads but both banks charge equally from one alternator. But those are 12v batteries, not 6v series making 12v. Earl Quote Link to comment Share on other sites More sharing options...
mopar_earl Posted October 15, 2015 Report Share Posted October 15, 2015 I did some research. For the way I want to do my system, I would need a 6/12 volt alternator equalizer and it would work perfectly. Only issue, doesn't appear anyone makes a 6/12 version. All I can find are 12/24 volt. Back to the drawing board unless I find a 6/12 equalizer. Too bad they don't make a dry cell 12/6 battery. Earl Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted October 15, 2015 Report Share Posted October 15, 2015 I have been told by farm smart techs that if you periodically rotate the batteries in their position it will give them ling life...many tractors run this very set up...passing on a snicky snack of info only... Quote Link to comment Share on other sites More sharing options...
Merle Coggins Posted October 15, 2015 Report Share Posted October 15, 2015 The equalizer you mention is what I was referring to earlier. Some of the Euclid trucks that I worked on were 24 volt for most of the systems, but use an Allison transmission with a 12 volt controller. They used the battery equalizer to maintain proper charging of the batteries while providing the 12 volt power needed for the transmission system. The series/parallel switch is also something I've played with a little bit. Some of the old Link-Belt excavators used it. They used 12 volts for the main electrical system but would switch to 24 volt for cranking only. They had a 24 volt starter and a 12 volt alternator. When you pressed the Start button to engage the starter it would also activate a large relay that would switch the battery connections from parallel to series, thus changing from 12 volts to 24 volts for the starter only. When you released the start button it would switch back to parallel (12 volts) I don't think that would be practical in your situation. Merle Quote Link to comment Share on other sites More sharing options...
janan5243 Posted October 15, 2015 Author Report Share Posted October 15, 2015 (edited) here is a link about batteries charging/discharging unevenly.http://all-about-lead-acid-batteries.capnfatz.com/all-about-lead-acid-batteries/lead-acid-battery-management/how-battery-equalizers-work/ Actually, after looking at the cost of the equalizers I've found, It would be cheaper to buy the 6/12 battery from Antique car batteries & use one 12V alternator. The shop I got the 6v alternator at said he would swap it for a 12V. Maybe the way to go. A little more expense but way less work. Edited October 15, 2015 by janan5243 Quote Link to comment Share on other sites More sharing options...
busycoupe Posted October 15, 2015 Report Share Posted October 15, 2015 I don't recall you ever mentioning why you wanted to switch to negative ground. The only thing you mentioned in your first post is that you wanted the cigaret lighter socket to be wired 12v neg ground. If all you are trying to do is power a gps unit or a phone charger or modern car stereo you my be better off using a voyage inverter. They are available from places like Custom Autosound for less than $100 and will allow you to keep the car 6v pos ground but still power your low draw 12v neg ground assesories. I have one in my 48 Dodge that I use to power a modern Sony radio/cd player. Dave B. Quote Link to comment Share on other sites More sharing options...
janan5243 Posted October 16, 2015 Author Report Share Posted October 16, 2015 Busycoupe; you are correct about one of my first posts. In that first thread, I believe Plymouthy pointed out that I would have to isolate grounds. Things have changed since then & I may be wrong but it appears that you haven't read this whole thread. I actually own a 6 to 12 converter. I am using stock antenna for stereo. No longer an isolated ground. I have a 12V HEI ignition system that I want to install, convertor will not power that & we run into the ground problem again. So I decided to convert to neg. grd. My cigarette lighter is powered by 12V. I have a triple power plug connected to it for GPS, cell phone charger, Ipod, etc,etc. It seemed to be a whole lot easier to convert to neg. grd. than to try & isolate everything. I made a mistake when I converted & am now rectifying it. It was an expensive mistake but I can't change it, I can just move on. Quote Link to comment Share on other sites More sharing options...
deathbound Posted October 16, 2015 Report Share Posted October 16, 2015 Maybe I'm missing something, it seems it would be easier to convert to 12V negative ground. Quote Link to comment Share on other sites More sharing options...
mopar_earl Posted October 16, 2015 Report Share Posted October 16, 2015 (edited) Maybe I'm missing something, it seems it would be easier to convert to 12V negative ground.Depends on the car. On my car I have loads of 6v items. The early cars aren't bad. My 52 has a lot more items to contend with. For example.(2) 6v blower motors Gyromatic controls Clock (don't know if it will work on neg grnd) Radio (don't know if it will work on neg grnd) 6v wiper motor Than you add all the standard stuff Ignition coil Electronic ignition (if done) Bulbs Turn signal flasher Choke Horns Horn relay Fuel gauge Starter solenoid For me that's more work and probably expensive. I'd have to buy a lot of voltage reducers. High amp ones at that for the motors. Easier to throw a 6v alternator on it and if wanted one of those 12/6 volt batteries to get 12 and 6 volts. Maybe parallel two of those 12/6 volt batteries for more cranking amps. Earl Edited October 16, 2015 by mopar_earl Quote Link to comment Share on other sites More sharing options...
janan5243 Posted October 16, 2015 Author Report Share Posted October 16, 2015 I'm with Earl. Initially it seemed easier & less expensive to do it the way I did. 2 6V batteries in series, 1 connected to original electric, other for 12V tap with a 12 V alternator. After buying 2 Red Top Optima 6V, found out that 12V alternator would not charge them equally. So either 6V & 12V alternators connected to proper circuits or buy 12/6 battery from Antique car Batteries & use 12V alternator. I need to talk Antique battery & find why their battery will charge correctly. If i'm comfortable with their answer I might bite the bullet & spring for their battery & swap 6V alternator for 12V alternator. Earl; with that 12/6 battery, they tell you that you need a 12V charging system. I'll post whatever I find out. Quote Link to comment Share on other sites More sharing options...
mopar_earl Posted October 16, 2015 Report Share Posted October 16, 2015 Yes the 12/6 is a 12v battery with a tap off 3 cells of the 6. So yes, it needs a 12v alternator. Earl Quote Link to comment Share on other sites More sharing options...
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