Upgrading Starter Battery - how to guide

Once we get to our 1st campsite we will stay there for 6 nights (will probably go out in a van 2-3 times), then we are traveling about 200 miles to different region (stay 3 nights), then travel up north towards Brittany 170 miles and stay 2-3 nights on different campsites and then travel 100 miles towards Normandy and stay 2 nights before sailing back to the UK. On the first two campsites (longest stays) we will have EHU when I can plug my CTEC battery charger anyway to top up the starter battery.

Definitely it has never dropped below 12v for the last 4 weeks according to the data in battery monitor. Lowest it went was 12.1v.
You have no worries with that battery to go to France, when you're back and have a couple of hundred pounds spare, drop in a 95Ah bosch AGM.
 
The battery testers are probably looking more at the cranking amps, over time batteries loose active surface area on the plates so with less surface for the chemical reaction the less current is generated.

I'd agree though that the other indicators look fine.

On the other hand it's 3.5 years old and not regularly charged and it's an EFB not AGM. A new battery from a trusted source isn't that much more than a full tank of fuel.

Personal view is you probably want to replace it before winter but I probably wouldn't risk disrupting things so close to a trip. Have a plan with your CTEK and I also endorse having a NoCo Boost - I started a train with mine...
 
The battery testers are probably looking more at the cranking amps, over time batteries loose active surface area on the plates so with less surface for the chemical reaction the less current is generated.

I'd agree though that the other indicators look fine.

On the other hand it's 3.5 years old and not regularly charged and it's an EFB not AGM. A new battery from a trusted source isn't that much more than a full tank of fuel.

Personal view is you probably want to replace it before winter but I probably wouldn't risk disrupting things so close to a trip. Have a plan with your CTEK and I also endorse having a NoCo Boost - I started a train with mine...

aha. I was just about to ask a question what's going on with my battery (all the parameters on the battery monitor look fine, its holing its charge, just had a look 5min ago since yesterday its on 12.45v, looked into the historic data for a month it settles between 12.3 -12.2v, starts fine, start-stop works fine) and then i saw that you replied clearly indicating that the battery tester is looking more at the cranking amps, which could then explain different results (battery monitor and the battery tester indicating different parameters).

I will definitely leave it until we get back and look into getting an replacement. Looked at Tyna website and entered my reg it just gives me an option for direct replacement EFB batteries, but other members get AGM as a replacement. Spoke to my local independent garage and they suggested going for like-for-like. I am wondering can replacement into AGM battery could disrupt the existing connection to my leisure battery (factory fitted underneath passenger seat which supplies the campervans lights/fridge etc), which trickle charges when driving. It was professional conversion by Rolling Homes from Shrewsbury and their vans come with factory fitted LBs)?

So, even if the battery has 12.4v charge it could find it not be able to start the engine due to the low cranking amps available, is that correct?

I saw your post where you started the train with your NoCo booster, hahahaha, well done, you don't hear that everyday to be honest. I looked into getting one, but there are so many to choose from and i am bit lost to be honest there is GBX45, 55 and 75. My campervan is 2L 150bhp TDI. So, which booster to go for?
 
So an EFB and an AGM are identical in terms of charging profile but generally the AGM is physically the better battery especially in demanding stop start situations.

If you have a stop start system but only the basic split charge relay then there are a couple more things to take into account when changing as the batteries are effectively ganged together as a bank. The factory system will use identical batteries which is the ideal. However rather than replacing both you'd be better spending the money on changing to a decent DC-DC charger (split charge will only be charging the leisure battery to 80%)

For the NoCo range experience on the forum suggests you want a 70 or above to reliably start a T6/6.1

So, even if the battery has 12.4v charge it could find it not be able to start the engine due to the low cranking amps available, is that correct?
Yep, the resting voltage is only telling you how much charge is stored in the electrolyte, how quickly that can be turned back into electricity is a factor of how much active plate area there is and you can only test that by putting the battery under reasonably heavy load.
 
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So an EFB and an AGM are identical in terms of charging profile but generally the AGM is physically the better battery especially in demanding stop start situations.

If you have a stop start system but only the basic split charge relay then there are a couple more things to take into account when changing as the batteries are effectively ganged together as a bank. The factory system will use identical batteries which is the ideal. However rather than replacing both you'd be better spending the money on changing to a decent DC-DC charger (split charge will only be charging the leisure battery to 80%)

For the NoCo range experience on the forum suggests you want a 70 or above to reliably start a T6/6.1


Yep, the resting voltage is only telling you how much charge is stored in the electrolyte, how quickly that can be turned back into electricity is a factor of how much active plate area there is and you can only test that by putting the battery under reasonably heavy load.
Just had a look at my LB (VW factory fitted under the passenger seat) and it's an AGM one. Could I then replace the SB with the same (AGM) so they would match then?IMG_20240711_100123528_HDR_AE.jpg
 
So the ideal is to have identical batteries and same age - but if you change the starter and leave the leisure system as is I'd recommend you get that model of Varta AGM for your starter.

Are you certain the EFB starter is the original battery, I would have expected identical batteries to be fitted at the factory.
 
So the ideal is to have identical batteries and same age - but if you change the starter and leave the leisure system as is I'd recommend you get that model of Varta AGM for your starter.

Are you certain the EFB starter is the original battery, I would have expected identical batteries to be fitted at the factory.

SB is Exide EFB (we had a campervan from brand new). Conversion started and then the 1st lockdown and all that. Unless, the original factory battery got drained and they (convertors) had to replace it and chose the cheapest one and fitted Exide one instead?
 
Sounds plausible and doesn't change any advice, was just a curiosity :thumbsup:

I was puzzled as well to be honest. So, on our return (fingers crossed) we should be looking for a Varta AGM one for a replacement.

I am just looking on Amazon for NoCo there is a GBX70 and GB70, what's the difference with the X model?
 
The X is the newer model so it has USBC charging (in and out) and apparently better lithium cells.

The older model has slower USB charging but also 12v in and out.

Both a GB70 and GBX75 will do the starting it depends what else you find useful as a power bank. If that's not interesting maybe get the cheapest (likely GB70), if you want to power 12v devices go GB70 if you want to power USBC devices go GBX75

@Dellmassive is the NoCo guru so may have an opinion either way.

If you have Amazon Prime might be worth waiting until next week as 16/17 is Prime Day and there are often offers on NoCo kit - but make a note of the prices today to be sure you're getting an actual bargain.
 
The X is the newer model so it has USBC charging (in and out) and apparently better lithium cells.

The older model has slower USB charging but also 12v in and out.

Both a GB70 and GBX75 will do the starting it depends what else you find useful as a power bank. If that's not interesting maybe get the cheapest (likely GB70), if you want to power 12v devices go GB70 if you want to power USBC devices go GBX75

@Dellmassive is the NoCo guru so may have an opinion either way.

If you have Amazon Prime might be worth waiting until next week as 16/17 is Prime Day and there are often offers on NoCo kit - but make a note of the prices today to be sure you're getting an actual bargain.
Aha, will wait for the next week to see if on offer. £264.99 today's price.

Honestly, I am well surprised about the state of my battery, but I haven't driven it a lot as I've been away.

Fingers crossed that it lasts when in France on our road trip.

Really appreciate your assistance and advice.
 
Hey all, the Varta EFB+ battery currently installed in my T6.1 is on its way out and I now want to replace it with an AGM equivalent. Can anyone confirm that the larger battery such as the Bosch /Varta G14/Exide EK950 will fit in a T6.1? I see most installations are concerning the T6 and I'm not sure if there's a difference in how these batteries fit between the two models?

I've also noticed on top of my battery is a little connector box with cables, I'm assuming these are factory installed? Will these cause issues with how it fits on top of the bigger battery?

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Just read through large part of the topic, hoping you can help me confirm;

Its a 2017 2.0 TSI Manual gearbox LWB with START-STOP

I want to replace this little thing, when I bought the Van it was supplied to it, bit in the bigger picture I never gave it much attention.
Having some issues with the Van as well and thought, well, lets atleast replace this one, because I think it shouldnt belong there.

If I am correct, I should be able to install, the following battery, correct?

Bosch S5 A11 12V 80Ah AGM 0092S5A110



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Fitted the larger Bosch AGM 95ah today. It's a squeeze but helped by taking out the sliding dividers. I replaced the jacket and stuff some foam at the back then wrapped it with shock cord.

Just an idea, I changed the battery serial number to YYYYMMDD00 so I know when it was last changed. I usually write that in marker on the top of the battery too. View attachment 243805View attachment 243806
Hi! What jacket is that? Upgraded to the same battery 3 years ago and couldn't find a jacket at the time.
 
Hi folks,
So just read through this whole topic.
Can anyone confirm that the 95Ah battery will fit into a t6.1, all be it with a bit of a squeeze and as markc84 said, the box on top fits ok onto the larger battery.
Apologies, if I've missed it.
 
The Bosch 95Ah battery fitted in to my 6.1, good arm wrestle though. Being a poverty issue Startline I don't have the fusebox on top to worry about, perfect size, no problems.
 
Thanks DW.
On another point regarding coding. I have VCDS but my current lead says I need to upgrade to hex-v2 @ £225.00
obd11 looks to be a cheaper option.
Is there a massive difference in functionality apart from battery coding?
 
The Bosch 95Ah battery fitted in to my 6.1, good arm wrestle though. Being a poverty issue Startline I don't have the fusebox on top to worry about, perfect size, no problems.
Has anyone found a jacket that’ll fit this size battery yet?
 
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