TheSamba.com :: View topic - 1.9L tdi conversion

Wed Dec 19, 2018 3:26 pm

Hello Im seeking assistance with my 1991 vanagon with a 2001 jetta tdi ALH engine conversion.

The issue i am having is with the battery. I have a bosch battery stock to the van and fits into my 11-5 inch by 7 inch by 7 inch space under my seat. Here are the specs on the battery.:

Bosch
Part# 41-675B
SKU# 9073724
CCA @0 degrees Fahrenheit 650
CA @ 32 degrees Fahrenheit 780
RC Mins @ 25 Amps 105

Since its been colder out here near Philadelphia PA, i have been having trouble starting it. I called up a battery store (not pepboys or autozone etc) and with the space i have, the highest Cold Cranking Amps available is around 720.

I am curious what others have done since the battery designed for the 2001 jetta is a bigger battery.

I will consider all options. I thought about a couple things like relocating the battery to under the rear bench seat, making the existing compartment bigger, raising the seat somehow, and adding an auxiliary battery for starting and other accessories.

thanks in advance
PFA

Wed Dec 19, 2018 4:15 pm

I've been using a Duracell Group 40R T6 with 650 CCA in my ALH mTDI and it has had no trouble starting into the teens°F. I haven't tried colder than that this year. That battery will fit in the stock gasser battery location although mine is not there. You should make sure that all battery cables are in very good shape as you have a much longer run to starter than I have.

Wed Dec 19, 2018 7:43 pm

Can’t speak to cold operation but i managed to stuff this under the pass seat in a syncro tin top with a little bit of cutting and bending. I have also grafted a swivel seat on this side. Can’t recall if it gives more or less room. Note I notched it.

AutoCraft Platinum AGM Battery, Group Size H6, 760 CCA. AdvancedAuto does 15-20% off coupons almost every week.

https://shop.advanceautoparts.com/p/autocraft-plat...10210829-P

Insitu.

Wed Dec 19, 2018 9:01 pm

My question would be - what starter is installed? A TDI starter shouldn't require anything too huge, the group 41 you have should be fine.

Thu Dec 20, 2018 9:55 am

I have an Optimal Yellow Top (D32/78 ) in it's stock location in the engine bay.
However, looking at the Optima page, I see they have a NEW battery, the H6! 800CCA! 72Ah!
https://www.optimabatteries.com/en-us/yellowtop-deep-cycle-battery/h6

Thu Dec 20, 2018 10:07 am

I run a Group 41 in the stock gasser location on my ALH, cranks the TDI starter just fine.

Fri Dec 21, 2018 3:18 pm

As a seasoned mechanic I recommend doing an actual voltage drop test under starting conditions on both the positive and negative sides. Voltmeter from + battery lug to + starter bolt, ditto on negative battery lug to starter case. (“Lug” is important here, not the terminal(s) but the first thing that the battery has available to touch). With the van being so large won’t allow normal test leads to reach so just extend them with jumper wire, gauge doesn’t matter as this test draws no current but ohm test you extended leads) Expect near zero volts (>0.1) reading on your meter while you crank the engine over. Report back.

Brian