Thread: Problem Charging Aux Batteries with Smart Charger

Hi,
I charge both batteries by connecting the charger across the starter battery when I have plenty of time and mains power available.

In the bush I usually only connect across the Aux battery. The starter should by now have disconnected the two (traxide SC80), and the solar panel is used if solar gain is possible, or later in the afternoon I will fire up the generator to power the charger (multistage)

I'm curious as to how a charger could cook a battery, unless the charger was faulty.

Cheers

May I suggest to ring Tim and ask him what works with his kit.
I run his gear but with a different set up so what works for me wont work for you.

Something was wrong with the Thumper or Charger to cook it with a simple charge.

What mode was the charger in?

Originally Posted by Tombie

Something was wrong with the Thumper or Charger to cook it with a simple charge.

What mode was the charger in?

Mmmm.... thumper has been fine up till now.....the charger was in "normal" mode & it normally indicates charging stage/levels via 4 led lights. Only got up to led 2. I'm wondering if the charger is not capable of charging three connected batteries?

The MXS 7.0 can charge up to 225Ah of batteries in its design spec.

If the charger was in Power Supply mode it could potentially harm the Batteries but that's after a long time.

How olds your Thumper and how discharged was it? Was it running any devices at the time?

Originally Posted by Tombie

The MXS 7.0 can charge up to 225Ah of batteries in its design spec.

If the charger was in Power Supply mode it could potentially harm the Batteries but that's after a long time.

How olds your Thumper and how discharged was it? Was it running any devices at the time?

The charger was in charge mode, not power supply mode.

The thumper was about 3 yrs old.

Fridge in car was off.

There is nothing magic about the Traxide system. All it does is disconnect the starter battery from the aux battery when the voltage drops enough. The rear Anderson plug is just a direct connection to the aux battery. If you apply a voltage to the Anderson plug it just applies that voltage minus losses in the wiring to anything connected to that circuit. It will also apply voltage to the starter battery if they are connected at the time.

I'm not sure what you think is happening but that is all it is. The Traxide system won't affect anything that you plug into it and can't damage anything by itself. There is probably either a problem with the way you have plugged the Thumper into the system or the CTEK is faulty. Failing that, there could be a problem with dissimilar battery types being connected together. The starter battery is a calcium battery which can be charged at a higher voltage than AGM or conventional batteries but I don't know what your other two batteries are. Perhaps the Thumper didn't like the voltage that the car was providing to charge the starter battery and that was what cooked it. The CTEK wouldn't charge because the battery was already cooked.

The Optima AGM battery that is usually used as the aux battery in D4's is more robust then most AGM batteries and doesn't mind high charge rates and voltages and is perfectly suited to the D4. It is possible that the thumper is not so suitable but you haven't provided any info on how it is connected to the system or what type of battery it has that I can see. Is it connected via the 12V plugs in the rear that are part of the Traxide kit?

What do you mean by a cooked battery? Is it boiling, not holding charge, low voltage or what?

Originally Posted by BobD

There is nothing magic about the Traxide system. All it does is disconnect the starter battery from the aux battery when the voltage drops enough. The rear Anderson plug is just a direct connection to the aux battery. If you apply a voltage to the Anderson plug it just applies that voltage minus losses in the wiring to anything connected to that circuit. It will also apply voltage to the starter battery if they are connected at the time.

I'm not sure what you think is happening but that is all it is. The Traxide system won't affect anything that you plug into it and can't damage anything by itself. There is probably either a problem with the way you have plugged the Thumper into the system or the CTEK is faulty. Failing that, there could be a problem with dissimilar battery types being connected together. The starter battery is a calcium battery which can be charged at a higher voltage than AGM or conventional batteries but I don't know what your other two batteries are. Perhaps the Thumper didn't like the voltage that the car was providing to charge the starter battery and that was what cooked it. The CTEK wouldn't charge because the battery was already cooked.

The Optima AGM battery that is usually used as the aux battery in D4's is more robust then most AGM batteries and doesn't mind high charge rates and voltages and is perfectly suited to the D4. It is possible that the thumper is not so suitable but you haven't provided any info on how it is connected to the system or what type of battery it has that I can see. Is it connected via the 12V plugs in the rear that are part of the Traxide kit?

What do you mean by a cooked battery? Is it boiling, not holding charge, low voltage or what?

Thanks for the detailed advice. Your explanation at the beginning is what I expected to occur, ie, plug charger into Anderson plug at back of car and all three batteries would charge.(assuming start battery was still connected via the traxide controller).

The Ctek charger has in the past successfully charged the Thumper on its own.

Voltage whilst charging was just over 14v.

The thumper is connected via Anderson plug into the Traxide kit. (The wiring was modified by Tim to allow for the 3rd battery in the car)

This morning the thumper was very hot and smelly so I disconnected it from the system. Took the top off and the batteries inside the housing are swollen..voltage indicator is now showing 4-5V, so I assume a couple of cells are now stuffed. Whilst it was charging I noticed the amps input was low at around 1-2A. Normally it would start a lot higher than that & reduce over time.

I'm assuming the cells inside the thumper are AGM, similar to the Optima.

Based on your comments it seems that perhaps the thumper was on the way out?

I'm a bit reluctant to plug the charger back into the rear Anderson plug with just the optima and start battery. Any way of testing the charger for faults, in case it was the cause?