Auxillary Battery Upgrade Questions

[SSWesty]

[davevickery]

I'm not certain you charged all your batteries all the way. Only the starter seems fully charged. You can read 12.8 volts right after putting out on the charger but that is not a resting voltage. Did your charger go into float mode on the aux batteries?. You would have seen voltages as high as 14.5 then down to 13.6 in float. What kind of charger ate you using?. How are you determining 12.8 resting volts?

[outcaststudios]

wicked usah name.
_________________
'88Doka JX td
'69 westy
(rip)couple bugs
(rip)three type III"s
(rip) '81 vanagon
a bunch of french stuff,and 9 motorcycles.

https://www.thesamba.com/vw/classifieds/detail.php?id=2573791

[candyman]

[Maine]

The charger is a NAPA 85--323A 12v 10 amp model. I set it on deep cycle/gel/agm the charging light alternates between red and green as the battery approaches full charge. Maybe I stopped to early I did not want to over charge. Is that not a concern?
Regarding the 12.8v resting I checked the battery's with a multimeter both when they were unconnected with each other (on the bench) and then again when they were hooked up.

[crazyvwvanman]

The GW aux battery charging setup is notoriously weak and with a tendency to undercharge aux batteries. This is because of the wiring path it uses to connect the aux battery to the starter battery. As a quick simple test use a set of jumper cables to connect the positive post of your starter battery with the positive post of your aux battery. Same for the negative posts. Then run your voltage tests again, with engine running and with rpms raised. This will show how much alternator sourced charging voltage you could have at the aux battery if there was a stronger wiring connection between the starter and aux batteries. Post your finding and sort through the suggestions.

Mark

[E1]

That's one fine test, Mark.

Would one expect a very slight drop in power at battery 1 since more's getting through to battery 2?
_________________
‘84 Westy, 2.1L with Digijet, 5.43 R+P, GT Gears
"Adding power makes you faster on the straights.
Subtracting weight makes you faster everywhere."
— Colin Chapman

[crazyvwvanman]

Yes, Ohm's Law rules. Keep in mind that if you have the aux battery fully charged this test may not show much, since what you want to test is CHARGING of the aux battery when it is low, not already full!

Mark

[E1]

Thanks!
_________________
‘84 Westy, 2.1L with Digijet, 5.43 R+P, GT Gears
"Adding power makes you faster on the straights.
Subtracting weight makes you faster everywhere."
— Colin Chapman

[T3 Pilot]

https://www.gowesty.com/product/electrical/25082/lifepo_aux_battery?v=
_________________
1988 Vanagon

The most important part in every vehicle is the nut behind the wheel......

[E1]

An expensive lithium battery is not the solution here.

Proper wiring and isolation is.
_________________
‘84 Westy, 2.1L with Digijet, 5.43 R+P, GT Gears
"Adding power makes you faster on the straights.
Subtracting weight makes you faster everywhere."
— Colin Chapman

[davevickery]

[Maine]

I enlisted a friend to help look at the wiring and we may have found the problem. The original setup eventually worked its way to the fuse box and the down to battery #2 (under the drives seat).
We are going to rewire with a more direct route and replace and upgrade the original Go Westy wiring inducing a new and heavier ground wire. We will aslo replace the isolator.
We are also going to recharge the battery the right way as Dave suggested.
In a few days once we get done I will post the numbers.
Maine

[Paulbeard]

If it goes up to the fuse panel, it might mean some of your standard features (clock, map light, radio) are running from that. On my 87, fuse #3 is the aux circuit and everything connected to it draws from the aux battery.
_________________
Currently -> Frida: 87 Tizian Red (mostly) Vanagon GL Westfalia w/ 2.0L ABA conversion
Formerly -> Steward of a 73 Super Beetle (Beater) and 67 Beetle 1300 (Little Max) both names by POs

[Maine]

This is an update on my original auxiliary battery post. I added a second battery to support the Norcold fridge, lights, radio etc. when off the grid. The problem was the voltage readings seemed low: 12.4 when not running, 12.8 when driving and less when adding power drains, fridge, lights, radio etc.
Well we upgraded the wiring with higher quality heavier gauge and changed the isolator and fully charged the batteries. The original wiring was from the Go Westy Auxiliary Battery Kit.
Voltage readings now are:
12.8 at rest no draw
14.1 going down the road no draw
13.6 fridge on, radio on, lights on etc.
Above 12 for two days with engine off (off grid scenario) . fridge on, using lights and radio occasional.
Maine

[Paulbeard]

Score one for moving on from the GW kit.
_________________
Currently -> Frida: 87 Tizian Red (mostly) Vanagon GL Westfalia w/ 2.0L ABA conversion
Formerly -> Steward of a 73 Super Beetle (Beater) and 67 Beetle 1300 (Little Max) both names by POs

[SSWesty]

Glad you got it sorted out.