Help from Bushtracker: Batteries and Charging Systems, Anderson Plugs

Submitted: Friday, Dec 10, 2004 at 01:34
ThreadID: 121636 Views:5620 Replies:0 FollowUps:0
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Current Battery and Charging problems:

Almost all of the current battery problems of late, are with people unknowingly misusing their 12 volt systems. While there have been rare occasions of defective batteries, they are only in about 1 in 200, to about 1 in 500 in actual occurrence. When someone has crashed all three of their batteries, while we are getting it handled on a warrantee basis some of the time, the truth is that the people do not have three defective batteries, they have unintentionally ruined their batteries by running them down too low or leaving them down low for too long. Some examples of this unknowing abuse of their battery systems are like the following:

1) They are running the batteries too low with their inverters, when they really cannot afford or don't have the excess power... Some inverter choices did not have a built in Low Voltage Disconnect until recently... People need to live within their power limits, and not use power hungry luxury items when the weather is off or their batteries are not full up…. Flat screen TV’s, stereos systems, satellite dishes and decoders, microwaves, and other luxury items need to be used sparingly when the batteries are not up in the upper range of being fully charged. We state that 3 –120 watt panels and 3 batteries hits the 90% of Customer satisfaction, but then many are adding more stereo, TV, satellite dish, type systems after that, when they really should go to 4 panels and 4 batteries if they are going to do that…

2) Some people are continuing to run accessories when the batteries are too low, fridges in tow vehicles and the like. As I have said, People are unintentionally ruining good batteries through over use-abuse running them down too low and or leaving them there too long... We have tried to build in the LVD, (Low Voltage Disconnect) to cover this, but the Anderson Plugs bypass the system and allows unintentional abuse, running them down with luxury items in the tow vehicles, stereos left on, extra fridges, and the like in the tow vehicle that is running through the Anderson Plug bypassing the LVD protection in the caravan itself and running off the batteries directly. The Anderson Plug extra connection, should be reserved for people that actually have surplus solar power, which is what it was designed for, like 4- 120 watt panels and 4 batteries. Then it makes sense.

3) Some people are even actually overcharging their batteries, with large cable running to Anderson Plugs, allowing the alternators to pump up the batteries too high when on long driving trips. The sealed batteries don't like voltages over about 14.5v for very long, and alternators on tow vehicles will often put out up to 15 volts and hold them there for as long as the engine is running. This hurts the batteries over time, depleting the electrolyte. This is another case of unintentional abuse of the batteries.. And why we do not like to put in the larger battery cable size of wire back to the 20amp Anderson Plugs. If we restrict the wire size to 6mm, yes we do get about a half volt loss, but that suits the batteries better as most tow vehicles put out 14.9-15 volts and the Gel, Hybrid, and AGM batteries are restricted to 14.4-14.5. This can be overcome with a large Diode, which will drop the voltage a half volt, but this will restrict the Anderson plug to charging only, not drawing power back, as the Diode blocks it in that direction… There in is its own problem, more in another section on “Anderson Plugs”..

4) Some people are actually adding more toys on board later; some have even directly connected to the battery system, allowing them to use power and run the batteries lower than they are designed for.... After having abused or killed their batteries, they are often “in denial” as many do not understand how the electrical system works, and we cannot entirely stop them from unintentionally abusing it...

And then, all of this ends up our fault of course... There is no easy way to handle this... Some people are just using too much power with elaborate stereo and TV and satellite systems, and other accessories like Satellite Decoders and extra fridges, and the like... For instance one person, came in with an
unaccountable power draw draining their batteries overnight, that was chased down to a Satellite Decoder that was drawing 3 amps 24 hours a day in power even when not in use... It is very hard for us to regulate how much power people are able to use, and about one in twenty of our Bushtracker Owners just do not understand or pay attention to the power available, as they are unintentionally abusing their battery systems one way or another. It is an ongoing challenge for us...

One way we have tried to overcome this is to try and educate the Owners on how to live with 12volt storage battery systems, so we are ever increasing the size of the Owners Manual with added information… Well and good, but some people do not read the Owners Manual… . It is almost a joke about men, that they do not read the Owners Manual until they have broken something. We strongly recommend that our manual is read to prevent damage.

Another way we have tried to overcome this is to continue to evolve automated LVD and HVD systems. For instance, we now have an LVD (Low Voltage Disconnect) that we can put in the Anderson Plug line. If people leave a stereo on, a fridge running, something that is a current draw through the Anderson Plug, we have a neat LVD device that will automatically cut out the circuit and only put it back in when the voltage rises to a preset level in the batteries… Good idea, but it costs around $300, so the protective cure is more costly than the occasional case of people ruining their batteries.

Another and the best way may be by building a stronger battery that is better able to survive the abuse.... This has been done. We have the first 200 in the country. They are a 100 Amp Hour Hybrid AGM (Absorbed Glass Matt) battery with German A-200 Gel. We have severely tested them with huge cycles, and even left them down in a badly discharged state, abusing them for three days as a severe test only. A battery is really about 50% discharged at around 12 volts and fully discharged at 10.5 volts. We left them at 10.5 volts for three days and then recharged them with a 240v charger, and they have survived and had been fully recharged. While we do not encourage or advise such extreme abuse, we have tested them to that level ourselves in our own Quality Control research. We are not saying that they cannot be ruined, but they survived some rigorous testing that would have ruined other batteries…

We are always trying to build better systems and equipment to keep the Clients from unintentionally ruining their equipment.

Another Topic, Relevant to battery charging, is the larger 175 amp Anderson Plug and larger battery cable connection of 14mm: The problem with the larger Anderson Plugs and large cable, such as the 175 Amp Anderson Plug and 14mm cable, is that it grossly shortens the life of the tow vehicles alternator as it is not designed to run at a “continuous duty cycle” charging five or more batteries up in the combined tow vehicle and caravan. Let me explain: The alternator has a regulator that runs the alternator flat out at maximum capacity until the batteries start to come up in voltage, and then it tapers the charge down to almost nothing as the batteries get to their higher voltage. The problem comes in with five batteries or more, where the alternator is running at maximum capacity for too long and it does not have the cooling capacity to do so and cooks itself. Continuous duty alternators are about twice the size of normal alternators and have a large heat sink and cooling fans to run flat out for a long time… The normal alternators are only designed to run one or two batteries, so they only run at maximum capacity for shorter periods of time before the higher voltages make the regulators throttle the alternator back to lower output. I, Steven Gibbs, have personally over eight years of experimenting, cooked a half dozen Toyota and Ford alternators in trying to overcome this problem. The answer for five batteries or more in the vehicle and the van, and a very large cable and plug, is a continuous duty alternator at a very high cost, or restrict the wire size to diminish the problem, which has worked well. Even if you put in the very large cable and plug, and even with the continuous duty alternator, you have the overcharging problem on the van batteries, that has to be overcome with a Diode to drop the voltage that half volt difference. It is all just not worth the effort and expense… So, while well meaning people try and eliminate the small voltage drop that comes with smaller sized cable, it can actually work to their disadvantage to run the larger cable. People need to fully understand that we do what we do, for a reason.

The original design of the Anderson Plug: I originally incorporated the Anderson Plug concept into my own Bushtracker van in 1997. This was the second van to move up to four panels and four batteries, to use the excess solar to power my 100 litre Trailblazer fridge in my tow Vehicle. Sometimes in a remote setting there was no where to go on a day trip, and the batteries in the tow vehicle needed a half day running to be charged up every other day, and so the Anderson Plug allowed the use of the excess solar in the Bushtracker. There was also an added benefit, as the same condition of having to run the tow vehicle every other day for a half day to charge the batteries in the tow vehicle, existed in town. The Anderson Plug allowed me to use the battery charger to charge the second battery in the tow vehicle when plugged into 240v at a caravan park or for running on a generator, when there was nowhere to go on a long day trip.. Now, some people are looking at it differently: And they want to use the Anderson Plug for extra charging capability from their tow vehicle alternator to the batteries in the Bushtracker van. Now if this is the case, and they do not have excess solar, we can put in a 40 amp diode that will keep them from pulling power back from the van. This will also solve the high voltage problem produced by the alternator and keep it from hurting the Gel/AGM batteries as the diode drops the voltage about a ½ volt from 14.9 volts at the alternator to 14.4 volts at the caravan batteries. This will work with larger cable and the Diode in place, or we can just use the standard Anderson Plug and 6mm wire with its own ½ volt drop, and the system works well….

For more advanced Electrical Engineering explanations and calculations, please enquire on our E-mail address, and we will be happy to give you the reasons why…

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