D4D charging voltage

[plucker Advanced Member Find all posts View Profile Close plucker]

I have heard the same in a thread or two here on PP (but I can't find it back again ops: ) ... that the new setups don't charge at the same rate .. and that Redarc has changed the settings in their isolators to kick in earlier.

Page 1 Mate

[Chippy Addicted PP Member Find all posts View Profile Close Chippy]

That's were I've seen it ops: I must have been having a "Man look" :lol:

I knew it was around here somewhere :lol: :lol:

Thanks Plucker :roll:

Cheers
Chippy

[BIG BRUCE Junior Member Find all posts View Profile Close BIG BRUCE]

The folllowing are usual flooded cell lead acid characteristics :
The following is common for lead-acid batteries:

Quiescent (open-circuit) voltage at full charge: 12.6 V
Unloading-end: 11.8 V (min discharge point)
Charge with 13.2-14.4 V (some times called trickle charge)
Gassing voltage: 14.4 V (don't charge continuously at this voltage )
Continuous-preservation charge with max. 13.2 V
After full charge the terminal voltage will drop quickly to 13.2 V and then slowly to 12.6 V.
Conventional altenator regulators have what amounts to boost charge (about 14.2-5 v) the current limited by stator saturation ,as the differential voltage between the battery and altenator gets less the voltage drops to about 13.5-13.8 v .
An average start only discharges a battery by about 10% so it doesn't take long to recharge . The boost charge system is a carry over from old relay type regs and is nt necessary to correctly charge a battery ,in fact the opposite could be true . All the above is also seen in the current generation of processor controlled solar regs .

[Guest Close Guest]

Great info bruce .... did you eat a manual :?: :lol:

very detailed , sent you PM too mate .

billy

[BIG BRUCE Junior Member Find all posts View Profile Close BIG BRUCE]

Nah ! billys just dug it from the deep recesses of my memory . Unfortunate but I get paid to remember technical bumf like ,so that contractors who work for me do the right thing , though usually of wireless telephony type (34 years).
Been known to read just about any type of technical manual ,just like to know how things work I suppose ...................also not easily fooled by people who do work for me .

[Johnk Junior Member Find all posts View Profile Close Johnk]

Hi All,

My D4D also appears to limit the voltage to 13.4 volts which like other PP members is causing me issues.

I have a 120 A/Hr deep cycle battery in the engine bay as an auxiliary (runs the Engel in car) and an 80 A/Hr battery in my off road camper. Between the main start battery and the auxiliary is a Redac controller.

What I have found is the deep cycle auxiliary battery, and camper battery (if the camper is attached), are only being charged to 13.4 volts even after driving all day.

Hence both batteries are not being fully charged – around 14.2 volts. This means I am starting my camping holiday with depleted batteries.

Fortunately I have solar panels with a smart solar charger which lift the batteries to their required voltage but this normally takes all day charging at around 5 to 6 amps. The solar charger bulk charges the batteries till the voltage reaches 14.2 volts, then switches to absorption charge till the batteries reach 14.4 volts then switches to float charge (around 13.8 volts). The main battery is isolated by the Redarc.

I like Robbo plan to talk to Toyota and ask for an explanation. At $250 and $200 for the auxiliary and camper batteries I am not keen to have their life shortened. :evil: :evil:

JK

[Addy Senior Member Find all posts View Profile Close Addy]

Johnk,

14.2 volts fully charged :shock:

From my understanding a 12 volt battery is fully charged at 12.7

[Johnk Junior Member Find all posts View Profile Close Johnk]

Hi Addy.

I believe 12.6 volts (approx) is fully charged for a 12 volt flooded battery. Trojan deep cycle batteries are 100% charged at 12.73 volts and 10% charged at 11.51 volts.

To fully charge a used (depleted) battery requires a higher charge (voltage). In the case of Trojan batteries around 14.8 volts. To maintain a fully charged battery (float) requires 13.2 to 13.8 volts.

I found this on a web site witch is interesting.

“Some automotive charging system designers prefer lower absorption voltages, for example 13.8 VDC (Toyota?), to reduce water consumption and wet Low Maintenance (Sb/Ca) starting batteries to reduce cost. Over time, this combination tends to undercharge the battery and to cause electrolyte stratification which causes the battery to gradually loose capacity due to an accumulation of lead-sulfate or premature failures.”

“One solution is to periodically recharge the battery with an external charger to remove the sulfation or to increase the absorption voltage output to the battery.” - Boost charge the battery.

JK

[Big Fella Senior Member Find all posts View Profile Close Big Fella]

Here's a question for you all,

If I have a ARB dual battery system can I in theory attach may regualated solar panels to my rear anderson plug and charge my dual battery whilst (let's say) camping> Does this charge the starting battery as well or will the ARB isolator prevent this from happening or is there no problem to let this happen.

[Johnk Junior Member Find all posts View Profile Close Johnk]

Hi Big Fella,

I am not sure of the ARB isolator but most isolate the main and auxiliary batteries when engine is turned off and the battery voltage drops to around 12.5 V. How long it takes to get to 12.5 volts depends on the battery load.

Once the main and auxiliary batteries are isolated it is fine to connect solar panels (WITH A GOOD SOLAR REGULATOR) to the Anderson plug. I have been doing this for the last 3 years. I have a jumper cable witch sits between the camper and car with a plug for the solar regulator. The solar regulator then connects to the solar panels. Once connected I can sit in the bush sort of indefinitely (sun, water and beer dependent).

My battery isolator is a standard Redarc which isolates the main and Auxiliary. I know they also make an isolator which has 2 controlling circuits for doing what you suggest. Using a solar panel the camper and auxiliary batteries are charged and when the voltage reaches around 13.4 volts the isolator switches the main battery into the circuit and charges it also. I believe this is not a problem for the Toyota electrics but you had better confirm before implementing. :lol:

Cheers,

JK

[Addy Senior Member Find all posts View Profile Close Addy]

So with the redarc isolator it says that it switches charge to aux when voltage is 13.2 so this would have to be the voltage of the battery nothing to do with the alternator right :?:

[Johnk Junior Member Find all posts View Profile Close Johnk]

Addy,

Once the engine is started the main battery voltage (via the alternator) rises. Once the main battery reaches 13.2- 13.4 volts the isolator closes (solenoid pulls in) and the auxiliary battery is charged. When the motor is turn off the battery voltage slowly returns to its lower voltage (with Redarc less than 12.5 volts) which causes the isolator to open circuit disconnecting the batteries.

JK

[MattWhite Advanced Member Find all posts View Profile Close MattWhite]

I will get back to you later when I know more but I read today that some manufacturers are controlling charging voltage with the ECU or PCM. The reason given in the article was a reduction in emissions. Not sure if the D4D has this and not sure of other possible reasons but I'll get back to you.

Matt

[Crammy Advanced Member Find all posts View Profile Close Crammy]

I've been doing some testing on my batteries and have found that the batteries are only charging to 12.41 volts which is around 75% charged. I charged my deep cycle to 100% using a ctek charger about 2 weeks ago and haven't run anything off it since.

So in theory going by the recommendation not to discharge deep cycle batteries below 50% I've only really got a usable 28.75 AH out of a 115AH battery! :shock: Not really ideal.

I might look into using the ctek off an inverter to charge the battery while on the move rather than the redarc. Probably not the most efficient way to do things but at least I'll have the extra capacity.

[Dutchie140 Lurker Find all posts View Profile Close Dutchie140]

Lead Acid Batteries

Hi Guys,
I'm new to the forum but thought an engineers perspective may be worth a further 10 cents.
The open cell, no load voltage for a lead acid battery is 2.2 volts @ 22degC.
6 cells in the battery gives an open circuit voltage of 13.2V. A charging circuit needs to be higher than 13.2 volts to allow a voltage differential to exist and current to flow. A typical regulated supply voltage [historically] was limited to 13.8V to provide some form of current limiting. Current limiting is required to prevent excessive heat build up in the alternator, regulator and battery. Too much heat is not good for anything.

Newer and smarter regulators provide electronic current limiting and can provide better charge characteristics for the battery including limiting the output voltage when there is no current flow. Therefor some regulators will show a lower output voltage than they are capable of to protect other attached electronics in the vehicle. In other words, open circuit voltage tests do not necessarily give you an indication of the health or otherwise of the charging circuit. There are as many opinions as people on this topic.

A typical Voltage reading on a battery in situ would be between 13.2V and 13.8V and 3rd party relay suppliers should have considered this. Output voltages of 15V or more are typical where current limiting is in place and in accordance with design curves.

The moral..... 12V aint always 12V

Dutchie :? javascript:emoticon(':?')
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