Relocated battery under headlight (Page 2/2)
fieroguru MAY 27, 08:48 AM

quote
Originally posted by CDM:

@Fiero Guru

Can you give a little info on the BAT (battery) you have.
Positives an Negatives,

I read on the site it has 15hrs of energy, what does this mean.
Do I have to disconnect it when not in use, my fiero is rarely use, but if i fo out for a a weekend.
Should I have it on a constant trickler when in the garage?

Thank you in advance : )



I have ran the Dyna-Batt for 6+ years. It easily cranked over by LS4/F40 swap even when I left the car parked outside over winter for a month or two between starts. My car is a 3 season driver so while it would sit for a month or two in the winter, I never put it on a trickle charger, nor was there ever a need to.

These smaller batteries do not have the reserve capacity of a larger one, but as long as the car starts with the first 5 tries (if it doesn't, fix those issues) and your car doesn't have an electrical drain (like from a security system), it will start your car when needed. What it won't do is allow you to run accessories with the engine off as long as a full-size battery. So if you make it a habit of leaving your lights on when you park your car, or listening to the radio while the car is parked, that will result in a dead battery sooner.

If you store your car for months, or you have to run a trickle charger to keep a full-size battery charged between starts, you will likely have more issues with Dyna-Batt than I have.

As with any modification, go into it eyes wide open. Understand the benefits and compromises and pick your path. I am going to stick with the Dyna-Batt.
Will MAY 27, 09:31 AM

quote
Originally posted by Patrick:

There is absolutely no way that installing a regular sized battery at the corner of a car is going to improve handling compared to having it mounted low and centrally.



Right. The entire point of putting the engine in the middle is to collect the car's major masses into as small a footprint as possible. Moving the battery forward works against the reason the car is mid engine in the first place. Moving the battery also adds a bunch of copper to the car, and copper is heavy.

I think straight down from the stock location is about the best place in a Fiero to mount the battery... That keeps it as close as feasible to the engine for short cable runs, as close as practical to the car's CG without mounting it in the passenger compartment and puts it as low as possible in the car. I haven't done one like this, but the mini-battery shown above is especially well suited for that.

[This message has been edited by Will (edited 05-27-2020).]

GTFiero1 MAY 28, 11:38 AM

quote
Originally posted by Mike in Sydney:

Interesting project. I've seen battery relocation into the front compartment under the spare but this is the first I've seen off center. A couple of questions for you: 1) What's the advantage in relocating the battery to the front of the car? Do you notice any handling or ride issues with the additional weight of the battery so close to the front wheel? 2) What gauge wire do you use for the increased length of the battery leads?





If I was actively autocrossing maybe I would keep it in spare tire compartment more centrally located. When this car is done it will see probably 90%+ normal/leisure driving (which is probably most fieros) to which the weight location will make no real difference.

I'll use 0 gauge cable (welding cable) to run to the back. Power only, as ground will be short right to that lug I welded to chassis. Using 200a breaker right off terminal for safety. Engine will have multiple ground straps to chassis.
theogre MAY 28, 12:10 PM

quote
Originally posted by GTFiero1:
I'll use 0 gauge cable (welding cable) to run to the back. Power only, as ground will be short right to that lug I welded to chassis. Using 200a breaker right off terminal for safety. Engine will have multiple ground straps to chassis.

Using Car's frame as return ground from engine causes many problems. Far easier and worse if just 1 joint is dirty or loose.

Every joint adds resistance even when good sucking power creating lower volts to everything is bad.
Example: See my Cave, Electric Motors
But can be far worse...

Worse? How?
Like Iffy ground(s) can try to make coolant system to be a ground wrecking everything. Even rubber hoses. Coolant is good at conducting electric but will eat anything doing so. Even anti-rust chems in coolant wears out very fast when you have ground problems.
More so every time you start the engine as 1.5kw starter pulls ~ 120 amps just to run, inrush can be 200 to 300+ amps when first turn the key. Many have "upgraded" to 1.7kw starter that uses ~ 135 amps to run and higher inrush.
Will MAY 29, 10:37 AM

quote
Originally posted by theogre:

Using Car's frame as return ground from engine causes many problems. Far easier and worse if just 1 joint is dirty or loose.

Every joint adds resistance even when good sucking power creating lower volts to everything is bad.
Example: See my Cave, Electric Motors
But can be far worse...

Worse? How?
Like Iffy ground(s) can try to make coolant system to be a ground wrecking everything. Even rubber hoses. Coolant is good at conducting electric but will eat anything doing so. Even anti-rust chems in coolant wears out very fast when you have ground problems.
More so every time you start the engine as 1.5kw starter pulls ~ 120 amps just to run, inrush can be 200 to 300+ amps when first turn the key. Many have "upgraded" to 1.7kw starter that uses ~ 135 amps to run and higher inrush.



BMW ran the return current through the chassis on the E30's they built with the battery in the trunk. I need to check my E34 and W211 to see if they're done the same way.

[This message has been edited by Will (edited 05-29-2020).]

Dennis LaGrua MAY 30, 05:24 PM
The small battery mentioned in this thread is probably 270 CCH capacity. That's less that 1/2 of the battery capacity that came with the car. You can probably get by starting an engine that turns over on the first try, but leaving the headlights on for a few minutes may be a different story. I guess that it works for some so more power to you!

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