Battery Switch

[warrenpfo]

Forget how the 100 is currently setup can I use one of these off the + pos of my starter battery to then link to either Aux 1 battery or Aux 2 batter or (Aux 1 battery and Aux 2 battery). I.e i want to use it to isolate when in camp but at the same time have the option of linking Aux1 and/or Aux 2 battery.

Hope that makes sence.

 

[fridayman]

How are you charging the auxiliary batteries? If you are using the alternator, you may as well use a voltage sensing relay, with a manual connect function.

 

[Gary Stockton]

I think Warren wanted to be able to bring all the batteries into the winch circuit which the relay won't do. So it should work as long as you can charge them - maybe consider the relay as a day-to-dat method with a secondary circuit to include them on the winch ring main?

If course if you don't want to winch with them the relay is probably best

 

[warrenpfo]

I am still in the design phase and maybe should have provided more information so that you could give a more informed reply.

To simplify things for this question the plan is to have one starting battery with the sole purpose of starting the engine. Once the starting battery has reached full charge a voltage sensing switch will open it up to the 1[SUP]st[/SUP] aux battery to charge it and once this has reached full charge the same again will happen to the 3[SUP]rd[/SUP] battery which is the 2[SUP]nd[/SUP] aux battery in a removable battery box in the rear.

The plan is to only use the 3[SUP]rd[/SUP] battery for only the fridge on long trips otherwise it will be removed. The 1[SUP]st[/SUP] Aux battery will run all the auxiliary things like, inverter, usb charging points, GPS, Air compressor, cb radio and other bits.

My knowledge of electricity is somewhat limited and so there will be many further questions BUT back to the reason for the switch is so that if need be I want to be able to bypass all the voltage sensing switches and link the starting battery with either the 1[SUP]st[/SUP], 2[SUP]nd[/SUP] or both aux batteries if not to start a flat starter battery if the worst should happen but also to winch and to use it to isolate the starting battery when in camp so there is no chance of a draw on the starter over night or whilst parked up.

The batteries will charge off the alternator and using a ctek ds250s and the option of a solar pannel.

 

[fridayman]

My Cyrix vsr has a manual connect function (via a momentary push button) that I intend to use for start and winch assist (if necessary).

And then I fitted an isolator to each battery to be able to isolate them individually (this has been useful several times). I am also going to fit an isolator switch at the back in case of emergency.

 

[fridayman]

Your solar panel options may be limited with the ds250 - I can't remember, but I think it has a max input voltage of 17V.

 

[warrenpfo]

This leads me to my next question which if possible could we answer once the first question has been thrashed out and come to a conclusion.

When charging batteries I understand there are limitations when it comes to the alternator charging a number of batteries. That aside how does charging work best and here comes the first of the stupid questions.

If my starter is at full charge and for the sake of maths let’s call full charge 12v. When the 1[SUP]st[/SUP] Aux battery joins the party and let’s say it’s at 8v due to use over the night does the starter automatically drop to 10v as 8v+12v= 20v /2 = 10v per battery or does the starter stay at 12v whilst the 1[SUP]st[/SUP] aux charges??

Likewise if I was to be able to use my switch and connect all 3 batteries together to winch or start the car if I wanted to (yes I know it would be overkill) but for argument sake let’s say the starter is 12v the 1[SUP]st[/SUP] aux is 10v and the 2[SUP]nd[/SUP] aux is 8v how is the combined battery voltage calculated??

See I told you many stupid questions

 

[warrenpfo]

My Cyrix vsr has a manual connect function (via a momentary push button) that I intend to use for start and winch assist (if necessary).

And then I fitted an isolator to each battery to be able to isolate them individually (this has been useful several times). I am also going to fit an isolator switch at the back in case of emergency.

I plan on using the switch above as an isolator at the voltage sensing switch will not open unless the starter is at full charge....that is unless this is prone to failure or if advised otherwise.

Your solar panel options may be limited with the ds250 - I can't remember, but I think it has a max input voltage of 17V.

The solar panel will be used in Africa only to top up the 2nd aux fridge battery when parked up at camp for a few days. I am not set on the DS250s and am happy to go with something else if there is a better option out there.

 

[fridayman]

The ds250 is a great piece of kit! The only reason why I didn't go for it was because I found some excellent quality Sharp panels (all panels are not equal) that can put out up to 30V.

 

[warrenpfo]

The ds250 is a great piece of kit! The only reason why I didn't go for it was because I found some excellent quality Sharp panels (all panels are not equal) that can put out up to 30V.

Thanks ill keep that in the back of my mind. I dont want to get too far ahead of myself and will post a diagram of what i want and subject it to abuse on here and see where we go from there.

 

[Olazz]

This leads me to my next question which if possible could we answer once the first question has been thrashed out and come to a conclusion.

When charging batteries I understand there are limitations when it comes to the alternator charging a number of batteries. That aside how does charging work best and here comes the first of the stupid questions.

If my starter is at full charge and for the sake of maths let’s call full charge 12v. When the 1[SUP]st[/SUP] Aux battery joins the party and let’s say it’s at 8v due to use over the night does the starter automatically drop to 10v as 8v+12v= 20v /2 = 10v per battery or does the starter stay at 12v whilst the 1[SUP]st[/SUP] aux charges??

Likewise if I was to be able to use my switch and connect all 3 batteries together to winch or start the car if I wanted to (yes I know it would be overkill) but for argument sake let’s say the starter is 12v the 1[SUP]st[/SUP] aux is 10v and the 2[SUP]nd[/SUP] aux is 8v how is the combined battery voltage calculated??

See I told you many stupid questions

Warren these are the questions that I have been discussing at length WRT my truck. I too have solar charging on the third battery, but am using a Nat Luna power pack. I found this system too limiting, especially when not travelling for 3 days whilst in camp. As I'm running 3 Optima yellow tops, I also found the alternator just couldn't pump enough charge quickly enough into them.

So I have upgraded my whole system to a MAXAMP charger with a 3 stage alternator regulator and a triple battery bank management system.

Here are some answers to the issues we discussed ad nauseum over the last 3 weeks.

There are various Dual battery management systems, or battery isolator models on the market. Some use Diodes, other use Contactors or Relays, and some use solid state switching devices. Our experience, however, showed us that the problems experienced in the energy/power requirement fields of the 4x4 industry, is a little more complex then just a case of retro-fitting another isolator to the system.
The shortfall of most dual battery systems boils down to the inability of the batteries to accept full charge, in either a short period, or at a low recharge voltage level. As a total solution to multiple battery management requirements, we focus on supplying a holistic solution in our EBMS multi battery systems.
The PMP multi battery management system looks at the recharge-ability of the battery, combined with the ability of the alternator to produce optimal power. We therefore offer an intelligent battery isolator (Multiple battery management unit) that has the ability to "talk" to the alternator - which is controlled by a special Booster regulator. The EBMS150 (Isolator and battery management unit) coupled with the MXS 3-stage regulator, work together as a unit - but can also be operated independently should the situation require it.

• Battery isolators (Multiple Battery Management units such as the EBMS-150) are recommended in DC systems with two or more battery banks that are functioning in an isolated position of each other.
• The multiple battery systems have to be installed between alternator or charger and the isolated battery banks. The benefit of the solid-state battery isolators (Multiple battery system) is that the charge process for both batteries happens completely automatically - without utilizing any mechanical parts.
• By employing a Mosfet, the voltage drop is minimal and automatically compensated for between charger/alternator and batteries of the dual battery management unit,

High power alternators, coupled with the MXS Booster Regulator, will charge the correct way - if the sensor wires between the MXS and the battery poles are connected. Any cable losses will now automatically be compensated for, thus maintaining correct charging voltage at all times. The EBMS 150 is a multi battery management system and gives priority charge to the battery with the lowest voltage. This system can cater for 2, or even 3 battery banks - which frequently occurs with trailers and caravans.

An increase in the use of auxiliary batteries by many 4x4 users has meant that original alternators with regulator voltages set at between 13.9-14.1V, are too low to charge up deep cycle calcium, gel, or spiral-wound batteries. These batteries require a minimum of 14.4V to be fully charged.
The MXS booster alternator regulator offers this facility as well as 3 stage charging: Boost (15.5V); Charge (14.4V) and Float.
In many vehicles, high power is attemptedly drawn from the 12V (or 24V) system, especially when the vehicle is being driven at a low speed such as ‘Bush Driving’ or in heavy traffic.
A typical example of this is where the current drawn from the battery can be as high as 100A, whilst the alternator is only producing around 45Adue to the low rotational speed of the alternator. The battery bank will support the load only until such time as the stored energy runs out.
WHY 3 STAGE CHARGING?

The MXS Booster alternator regulator delivers an increase in available energy which often goes hand-in-hand with charging batteries more frequently and more intensively. This cuts down on charging time by between 20-35% - depending upon the application.
THE DISTINCTION: Practically all 12V, or 24V, alternators that are supplied with a standard propulsion engine by the manufacturer are intended for charging starter batteries. The maximum charging current is often limited to 50 / 60A and the voltage has been adjusted to a ‘float’ once this battery charging voltage level of 13.9V has been reached. This is a good point of departure for the starter battery, but not effective for charging auxiliary batteries. Due to the cycling conditions of the auxiliary battery, the best way to recharge the battery sufficiently in a short period of time is to offer increased charge voltage and to thus allow the battery to overcome internal resistance and this is the primary function of the MXS alternator booster regulator.
The MXS is set to 3 stages of charging: 15.5V in Boost; 14.4V in Charge and ‘Float’ mode.
This helps to increase charging rate, and thus decrease charging time. Some of the more sophisticated 4x4 batteries such as the Optima Yellow Top range are able to absorb charge faster than normal Deep cycle calcium batteries and are thus able to consume greater power from the alternator - whenever it is available. These batteries work exceptionally well with the Maxamp 120 System from PMP and can often be charged up from ‘flat’ to full in under an hour!.

THE VOLTAGE VERSUS AMPERAGE DEBATE
Many 4x4 owners mistakenly think that high alternator amperage is the trick to keeping your auxiliary batteries fully charged- not so, I’m afraid!
A 120A alternator may charge up the first 75% of your batteries faster because of the higher amperage, but, as they are usually regulated to 13.9-14.1 volts, they will go into float mode before your auxiliary batteries can get fully charged.
The reason for this is that your normal deep cycle calcium or gel batteries require around 14.4 volts to fully charge up. Thus a 55A alternator with a 14.4V regulator, would, ultimately, do a better job of charging up your auxiliaries than a 120A alternator with a 13.9V regulator. Of course, the best of both worlds is having high amperage alternator coupled to a booster regulator such as the Maxamp 120 system from PMP.
Another point of note is the battery charger you choose for charging up your batteries - when you do have access to the grid. It must be a unit that charges at 14.4V, and not at 13.9 or 14.1V, which means that the normal solar chargers would be fine. Incidentally, solar panels and their respective solar regulators are ideal for charging up auxiliary batteries, as they are set to charge up at 14.4V.
So, when ‘powering-up’ your 4x4, think voltage, and not just amperage!!

THE POPULAR SOLENOID OPERATED, BATTERY MANAGEMENT SYSTEM
The solenoid Battery Management systems has been well marketed throughout Southern Africa and are very popular among 4x4 users. However, we have spent most of the last 12 months removing these systems from our clients’ vehicles whenever we install the 120A Maxamp system!

The first issue is that they employ the Cole Hershey solenoid (which we also employ for the Unipower system). This solenoid is not designed to constantly switch under load – something it is definitely required to do when switching from Main charging to Auxiliary (when the’ timer’ switches over).
At this stage, say first thing in the morning, the auxiliary battery may well be 50% discharged and pulls as many amps as the battery permits (more for an Optima battery). This tends to gradually burn the contact points and voltage is then lost as a direct result. It eventually fuses in the ‘Closed Circuit’ position - when the appliances will pull from the Main battery - a dangerous scenario as it could compromise your available starting power
.
The second weak point is that they are not designed for more than a dual battery system – so can’t effectively be employed for trailers when the client already has vehicle auxiliary batteries installed. This also applies to a client wishing to have his 2 auxiliary batteries in his vehicle independent of each other – due to mobility requirements or having 2 separate fridges/freezers.
The third issue is that of deciding to install a more powerful alternator system (over 75% of our clients with Nippon Denso or Hitachi 55-80A alternators systems have this done). The extra amperage that our system generates, exacerbates this weakness, and the points thus burn even faster.
Customers often complain that their auxiliary batteries never really get charged up properly and that they switch back to Main battery charging too soon. This is partly due to the low charging voltage (13.9V) on the average Japanese alternators, but also due to the solenoid systems switching back frequently to the main battery which, by virtue of being a Lead acid battery, has different charging characteristics to the deep cycle calcium batteries.

The MXS, booster regulator that forms part of our power up-grade, also ups the voltage, and thus amperage, which also does not integrate well with the solenoid type system. Optima batteries (of which we sell a great many of the Yellow Tops) do not work well with the solenoid system, but very well with the MXS and the more powerful Maxamp alternator.
As a rule, we never install an MXS on any Japanese alternator as they have in-weaker bearings and weak diodes and thus cannot take the extra heat and power generated by our systems. We are, however, looking at offering a modified regulator system for Japanese alternators which will push up voltage from the usual 13.9 to a more respectable 14.3 – essential for properly charging up auxiliary batteries.

HIGH CHARGE ALTERNATORS
Many 4x4 owners, when auxiliary batteries are frustratingly running down from day 3 onwards, make the first ‘leap of faith’ into a splitter’ system, in the forlorn hope that this will solve their charging issues – it rarely does!!
Of course, managing your available power is important, but in most cases there is just not sufficient power to ‘go around’. Remember that your original alternator was solely designed to handle your own vehicle’s electrical demands - and not a couple of other auxiliary batteries that you added on to keep the beer, and dry Martinis cool!! (The latter will be shaken, not stirred, of course!).
The most effective way to improve the charge into your auxiliary batteries is to up the alternator output to around 120-150 amps for this type of application. Some people will double-up on their alternators which is also a good solution – if you have room, of course. However, once into mobile fridges, you are probably into air conditioning as well, in which case there will definitely not be room for a second alternator on your vehicle - unless you are driving a Motor home, or similar!
PMP offers a range of high charge, heavy-duty, alternators from 90-200 amps,. as well as the possibility of rewinding your existing stator to improve its output (Although this is subject to the make and model of alternator).
Coupling this extra alternator output to our MXS ‘Booster Regulator’ will also help reduce charging time.
When charging more than a couple of batteries at a time, it is a good idea to invest in an EBMS (Electronic Battery Management System) of which we have several models based on the intelligent microprocessor technology. This system diverts current to the most appropriate battery and also makes allowances for the type of battery it is charging at the time (Cranking or Deep Cycling).

Not sure if you will find any of this useful but it helped me understand what I wanted as I asked loads of what I thought were school boy questions.
PS.. its not a cheap fix!!

 

[Ken Brenton]

Warren
In SA I settled for a main and Aux battery isolated with a voltage sensor and "Cole Hersche" (spelling) type relay on my 80. This sensed when the voltage output of the alternator reached 14+ V and put the Aux battery in line. I also had a 80 W solar panel which connected across the Aux battery via a voltage regulator.
One of the problems you face is the type of battery you choose for the Aux, normal cranking or deep cycle. Deep cycle works better for long discharges on steady drain but require a higher charging voltage (0.5V) than the cranking battery. Now as you can't have 2 different voltages on a single point this raises the question do you overcharge your cranking battery or undercharge the deep cycle. Most of us chose the first option and put a diode between the earth of the regulator and the chassis This effectively drops the earth potential to -0.5V and thus increases the charging voltage. It worked for me for 3 years, never had flat cranking battery and always had cold ones and frozen food on overland trips
There are many write ups on the LCCSA site about Aux battery set ups.

Ken

 

[Ken Brenton]

Just to add further, regarding the paralleling up of all 3 batteries for winching. This will take some heavy duty switches as the winch can draw 400 Amps. Deep cycle batteries are not designed for short heavy load discharges such as that. So I only took the winch of the main battery, but with the engine running (normally the preferred way to winch) the deep cycle will still be in parallel and add some current to the winch. The contacts on the Cole Hersche relay that I used were rated at about 120 Amps and never burnt out.

Ken

 

[warrenpfo]

Many thanks, it makes for interesting reading and does make sense if i take it at face value not knowing any better. When i google Maxamp i get an RC car site and a site in SA that has very little info. Do you have a contact i could get hold of and an indication of cost.

 

[warrenpfo]

I think i have found the site. Plan my power in SA. I have sent them an email

 

[Olazz]

Yep was just about to post.

 

[warrenpfo]

From what you say it would seem i need to get there MXS –ALTERNATOR BOOSTER REGULATOR along with one of there BATTERY ISOLATORS & Dual battery management units. Did you upgrade your alternator or does the Alternator booster do the job.

 

[Olazz]

Warren I went with the following:

Maxamp 120-12 Alternator
MSX-12 3-stage regulator
EBMS 150-3 Triple battery-bank management

There is a simpler and cheaper option which we discussed and that is to stick with the original alternator and place a converter rated at about 20A between the alternator and the UTB auxiliary. This would then charge the UTB auxiliary,(or my Luna box via a switch). However, the reality was that the Optima batteries are really a little wasted with this application, so I did the whole job as I will be keeping this truck for some time to come.

I will be able to test it properly when next trip in November.