Anyone ever relocated their battery to the trunk?

[tosoutherncars]

I'm considering using BMW parts to relocate my battery (with a larger, modern replacement) to the trunk of my 1500. The idea being easier, quicker starts, more electrical capacity, and perhaps better weight distribution as a bonus.

Thoughts? I'd love to hear everyone's opinions...

-Duncan

 

[sparkydave]

Putting a bigger battery in won't increase your electrical capacity. Your capacity to run additional loads is limited by the alternator. Do you drive it in the middle of winter a lot? Even mine starts fine with a group 51 (550 CCA) during winter. If you do put it in the trunk, you would need some heavy cables to take advantage of any benefits of a beefier battery, otherwise you'd be having losses in the additional cable length. I wouldn't do it .

 

[lesingepsycho]

I moved my battery to the trunk and it has been great. Beside the cleaner looking engine compartment, I think it really does balance the car better. Also, it does allow for a larger/different battery. I went to the local home supplies store and bought a length of cable conductor off of a spool. Be sure to look at the specifics of the cable to make sure it meets your needs. I don't recall what the specifics of mine are but they have a big chart that you'll have to interpret (obviously it won't say "this one for cars"). Max amperage is probably most important. After routing the cable through the passenger side of the car, I soldered on the appropriate connectors and that was that.

JACK

 

[62Migit]

The batteries I have seen in trunks have some special safety equipment: a sealed battery case with a hose leading to the outside of the car to vent, and the battery is an AGM (absorbed glass mat) or gel-type battery that cannot leak acid into your trunk. Bad thing about AGM is that you can't fast charge them and they're expensive. On the other hand I've heard of them lasting over 10 years on a daily driver. /bcforum/images/%%GRAEMLIN_URL%%/smile.gif

Mark

Edit: Moving the battery might also mean that you lose a handy +12V source for accessories like a timing light. Miatas have a spare +12V connector in the harness for you to clamp to in the engine comparment. I have a feeling everyone snickers a little bit at me and my "modern" roadster. But really, Mazda has put some great technology into their design. /bcforum/images/%%GRAEMLIN_URL%%/smile.gif

 

[tosoutherncars]

Hmm, one for and one against, with one abstention! /bcforum/images/%%GRAEMLIN_URL%%/cheers.gif Any other pundits?

To provide a little more detail, some BMWs use really nice hardware; see this auction for example. I was going to use that, and a bolted-down battery, in a box, in the trunk. That way, I would still have a 'post' in the engine bay.

-Duncan

 

[Trevor Jessie]

Sooo.... you think the midget trunk(boot) is too spacious?

 

[Sarastro]

Certainly, you can do this, but do you need it? If the car starts easily with the existing battery, you probably don't need anything bigger. If it doesn't, are you sure it's the battery that's at fault?

If you've added a lot of high-current equipment, and I can't imagine what, in a Sprite, that might be, then the first priority should be a larger alternator, then a battery. A larger battery will help only if that extra stuff is turned on for a short time relative to the off-time--so there is time for the battery to recharge.

If you do install the battery in the trunk, you obviously must protect the car from battery leakage and make sure it is well supported and can't come loose on a bump. You also need to think out where you will locate the high-current lead, so it is not damaged by road debris, chafing, passengers, and so on. This is what concerns me the most--greater chance for a short circuit to the chassis and potentially a fire.

So, unless you have a genuine need, I would pass on this idea. By a "genuine need" I mean something like difficult cranking on cold mornings, which I'm told you occasionally have in Ottawa, and, then, you're sure it's the battery at fault. Even in that case, a better-quality, original-size battery might be all you need. You can get some pretty good batteries these days.

 

[Atrus]

One thing I am not understanding....everyone is talking about the "original sized" batteries....for my '68, I simply went down to Autozone and picked up a 450 or 550 cca (can't remember) top post battery and slapped it in. Yes, it is currently not held down, and yes, I do plan on remedying that in the near future. But, I really don't see how hard or bad it would be to fab up a hold-down. Mine phsycially fit with no problem right behind the heater core. Is this an issue in a different year or body style and just not mine?

 

[tosoutherncars]

Mine phsycially fit with no problem right behind the heater core. Is this an issue in a different year or body style and just not mine?

Well, certainly the battery in my 1500 is about half the size of the battery in my VW Golf. I would expect that the CCAs (Cold Cranking Amps) would be commensurately smaller. But yes, I would agree with those above wh have suggested that I'm overly complicating things, and that if the car is hard to start, the problem lies elsewhere than the location of the battery.

I think that, for now, I'll replace the (old, tired) battery with a new equivalent in the stock location. I have electronic ignition and a newly-rebuilt DGV carb waiting to go on, as well. I'll drive it with only those changes for this season, and then reassess the need / want of battery relocation.

And no, the Midget's trunk is definitely NOT too big! /bcforum/images/%%GRAEMLIN_URL%%/smirk.gif Point well taken!

-D

 

[jlaird]

Those long runs from the trunk will also effect the cranking power. Shorter is better.

 

[Bugeye58]

And 0000 welding cable gets expensive! /bcforum/images/%%GRAEMLIN_URL%%/grin.gif
Jeff

 

[aeronca65t]

Please note that I am not actually suggesting that you do this....

But the battery in my racer is neither in the stock location nor the trunk.
It is on the right side of the car, in front of the axle. I use a normal-size Group 24 battery This is on the big size for a race car, but I sometimes run without an alternator and the car has also been used in night races (with headlights fitted).

The battery hangs in a tray made from 1-1/2 angle aluminum and is a pain to change, but it places the battery in an almost ideal location in terms of weight bias. I use a remote master On-Off switch (required) and if I charge the battery or jump start, I connect to the remote switch terminal (plus ground). I sacrificed an old set of jumper cables (just one of the leads) to be used to bring the power to the engine compartment.

Battery is in front of the tube shock (ignore the yellow arrow)

 

[GreenHornet]

Those long runs from the trunk will also effect the cranking power. Shorter is better.

Gotta agree with that! If you do decide to relocate it then consider using a welding gauge cable for the ground and run the cable as close to the starter as possible. For some reason it will give your starter more energy. Something about the power loop being shorter when the starter is engaged.

 

[Jack_Long]

Re: Anyone ever relocated their battery to the tru

I made a battery hold-down with 2 pieces of threaded rod, 2 wingnuts and a scrap hunk of angle iron. Total cost about $1.50.

 

[asoupley]

Re: Anyone ever relocated their battery to the tru

...I sometimes run without an alternator ...

Why would you run w/out an alternator? Wouldn't that just drain the battery fairly quick?

 

[Bugeye58]

Re: Anyone ever relocated their battery to the tru

Many of us don't use an alternator on the race car. A fully charged battery will last for an entire race, without the extra weight and parasitic drag of the alternator. For endurance type events, we'll either install a charging system, or frequently change batteries.
Jeff