Hi all,

I will need to relocate the battery when I fit the M117 5.0 in my W111 Coupe, as it is currently on the way of the future tri-Y set-up. But rather than fitting it in another place in the engine bay I'm tempted to do like this guy did: http://www.zeebuck.com/bimmers/tech/batteryrelocation/underseatbattery.html

This is on a BMW 2002 but I have the same kind of room under the back seats. I would prefer this setup to a box in the trunk as I often carry all kind of bulky stuff and need the room.

I may not save much weight but the weight distribution will certainly be improved.

I read in different places that only one battery is often enough to start a four banger unless temp goes really cold.

I leave in DC and the last two winters have seen sub 0 F temperatures for a few days. I'm wondering in having two of these PC680 in parallel will give enough power to start a Megasquirted M117 5.0 at 0 F.? They are 220 CCA each so I guess would get 440 CCA and even more for the first 10 seconds?

Any experience here wth this kind of setup?

Thanks in advance!

I really like that idea. I've toyed with the idea of relocating my battery but space constraints have kept me from pursuing it. Never crossed my mind to run multiple small batteries in parallel. Since I have been known to camp in the TE I've also wanted to add additional batteries to use with an inverter. Until now I figured I'd have to ditch my spare tire or my rear washer reservoir to install an additional battery large enough to use with an inverter.

As for your setup, I think I'd want more than 440 CCA. Cars equipped with a M117 typically have batteries rated around 800 CCA. Not saying your setup won't work but I'd want a little more in reserve. That said, don't let me discourage you.

__________________

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Here are the specs of the PC 680 :

• 680 Cranking Amps @ 5 seconds
• 595 Cranking Amps @ 10 seconds
• 525 Cranking Amps @ 20 seconds
• 400 Cranking Amps @ 30 seconds
• 17 Amp Hours (20 Hr Rate)
• 24 Minute Reserve Capacity @ 25Amp Load
• CCA - 220
• Length 7.27"
• Width 3.11"
• Height 6.67"
• Weight 15.4 lbs.

CCA is 30 seconds at 0 F.

I've been looking for other batteries that would fit under the seat, even a bit bigger, but it's the PC 680 that keeps coming up. I'm sure that most of the time two of these in parallel would be OK, even by 0 F, as I the engine should fire in less than 10 seconds. But you never know. It's the day you need the power that something will go wrong. If someone knows of a better battery that would fit that application let me know.

Thanks!

A battery, by definition, is several cells. So using several small batteries should be fine. But I would keep the CCA the same or more.

If one is really worried on a cold day, just bring a jumper pack that day. Then attack to the alt at positive or some other positive post. Heck, you could even make a post with a nice cover. Then negative to any good ground in the engine bay. That way you can still jump if needed.

On a side note, I have seen several Bentleys and such come in with dual battery setups. But they have a switch so if one dies you have another to start from. Nice feature but it sure takes up room and adds weight!

__________________
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I found that one: http://www.qualitypowerauto.com/catalog.php?item=152

500 CCA. But at that price I may start with one and see how it goes.