Battery Brain

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My Battery gave up last week so, along with a new battery, I fitted a battery brain.

It wasn't too hard to fit and along with the battery brain I also needed a +ive battery terminal and a piece of battery cable.

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http://www.batterybrain.co.uk/faq.html

It's a battery isolation switch that operates by remote control.

Except it has an extra feature that automatically cuts itself off if it senses that power levels in the battery drop too low.

Which saves you getting caught with not enough power left in the battery to start the car if laid up with the alarm on etc..

So you can use it to either cut power to the whole car via it's remote.

Or you can leave it on and it'll do it for you if your battery gets drained by the alarm or clock, or if you leave something like the satnav plugged in or a light on etc..

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Tanguero said:

The alarm siren on a Cerb will go off if the battery is disconnected while the alarm is switched on! Still - I suppose it will tell you when your battery is low!

I believe it's the other way around, If the battery is connected the alarm activates.
Once the battery is reconnected and the alarm automatically arms itself you just have to deactivate it before it goes off.

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Jubes said:

Excellent job aide.

We've been discussing this very product in the thread below:

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

How did you secure the Battery Brain to the vehicle and do you have any close up pictures of the install please?

Many thanks.

Thanks Jubes,

I did have a good read of the thread above before I started, which was really helpful.

With the two cables secured to each side of the battery brain, and when it's all fitted there is virtually no play at all.

But I am waiting on a piece of aluminium plate from www.aluminiumwarehouse.co.uk

Once it arrives I'll bend it at 90 degrees and mount the battery brain to one side of it and then slide the other side under the battery to secure it. Once the battery is bolted down it'll hold the plate with the battery brain attached.

However, I did stick a sheet of 2mm thick adhesive neoprene foam to the side of the battery and then put a rectangular piece of hard plastic between the battery brain and the battery just in case engine vibration will cause wear while I'm waiting on the aluminium.

The original +ive cables don't need to be cut at all. I'll post a few more pics over the weekend.

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Tanguero said:

No, according to the Meta alarm manual (and practical experience on my car) if alarm is armed and you disconnect the battery the alarm will sound using the self powered siren. The point is that it prevents a thief from disarming the alarm by disconnecting the battery. The battery in the siren unit can last for several hours at full blast!

If you disconnect the battery when the alarm is not armed and then reconnect it, the alarm will automatically arm as you say.

That's a bit of a bummer actually, unless you always disconect the battery and disarm the alarm.

julian64 said:

Hmm, not sure about this, aren't the adaptives reset if you disconnect the ECU from the battery for a length of time. If so every time you start the car you'll have reset the adaptivs and the car will run like a dog for a few hours. Also you'll be effectively destroying the batteries in the NVram in the eCU plus the batteries in the alarm system?

I guess the lithium battery in the NVram, even though it's replacable, would be better off connected to the battery all the time.


Plenty of food for thought, at least I didn't cut the original cables! thanks guys

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julian64 said:

gerradiuk said:

I have a battery switch on mine & its never been a problem at all. It runs absolutely fine every time once warmed up properly.

But you are making future problems for yourself. The battery in the NVRAM isn't working while the main car battery is connected and neither is the ni cad battery in the alarm.

The Meta alarm is too old to be lithium, and nicads don't do any length of time flat very well.

If you are going to connect a small battery for the alarm and the ECU you might as well connect the main one with a battery conditioner attached, as apart from the alarm and the ECU I don't think there should be any other drain.

It's a little bit worse than that because the lithium battery in the NVram isn't rechargeable and is integrated into the NVram die itself. So if you leave the car completely isolated most of the time the NVram battery slowly drains.

When that happens, if you want the adaptive map's to be remembered in between battery disconnects, you have to replace the whole NVram chip because the battery is not a separate item.

I'm not sure if the chip is soldered on to the board either, so it could be a bit more of a pain to replace. Having said that, it's said that the life expetantacy of the NVram battery is 10 years and even though most cerbs are pushing 10 years of age, most of that time the main battery in the car would have been connected so the NVram battery wouldn't have been used to keep the NVram data safe.

I guess the battery brain is good if it's used as a battery fail-safe only and not as a battery isolation solution, but the problem there is, if the battery brain senses the need to isolate the battery and cuts power, then the alarm will go off!

I think I'll put the old battery back in the car with the the battery brain connected, leave the lights on, activate the alarm and wait until the battery brain isolator kicks in. When it does, if the alarm goes off then it's not worth having because the only way of getting around this would be to use one of the male spades on the permanently connected side of the bb, that Chimpandtonic mentioned, to stop the alarm going off, but doing that would defeat the purpose as the battery would still drain!

I think Julian64 is 100% right, the main battery shouldn't be disconnected and ideally put on a trickle charger.

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TVdinneR said:

What would you consider to be a "length of time" ?
Only asking as recently both the 4.2 & the 4.5 main batteries didnt cope too well with the cold spell. This coupled with the fact they weren`t being used.
Both batteries were removed, fully charged, conditioned and left out of the vehicles for a while, ie the 4.5 for 2 months and the 4.2 for 3 weeks.
The 4.5 is now being used daily just now and battery is fine, & car running great - touch wood.
The 4.2 is being used on nice days only at the moment and each time its put away for a week or two I disconnect the battery, with no apparent adverse effects when reconnected - also running great - also touch wood.
Am I to assume, from what I`m reading, this is not good practice !

It may or may not be the case unless the ecu draws current from the main battery, when the ignittion is off, to maintain the state in the VNram. If it does, then leaving the battery connected would preserve the NVram battery. If it doesn't then the NVram battery would always be in a state of decay when the ignition is off and ultimately would discharge to the point where it could no longer remember the adaptive data in between engine cycles. And a situation like that would manifest itself as just poor start up performance until the adaptives were re-learned.

Does anyone know if the ecu draws current from the main battery, when the ignittion is off, to maintain the state in the VNram?

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maxim-ic make them and it looks like the DS1230AB-200IND+ is a replacement. There looks to be similar options, that have a faster response time, that would suit as well for around $13.

Edited by aide on Saturday 18th February 16:25

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mickk said:

Slightly off topic but can you post the serial number of your battery you've just purchased, mine needs replacing and i can see you have a 072.

Is that all i need to ask for?

Thanks.

It fits ok, but there is no lip on the side near the bottom to bolt it down properly.

www.thebatteryshop.co.uk
Product Code: Y072YP
Description: Yuasa Professional 072 Car Battery
Item Price: £ 81.99
Qty: 1
Total: £ 81.99

Sub Total: £ 68.33
Tax @ 20%: £ 16.66
Delivery: £ 17.97
Total: £ 99.96

HTH