Replacement Leisure Battery and Split-Charge Advice

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UncleMatty
Apprentice Bongonaut
Posts: 8
Joined: Mon Mar 24, 2025 7:09 pm
Location: Edinburgh

Replacement Leisure Battery and Split-Charge Advice

Post by UncleMatty » Fri Nov 07, 2025 4:36 pm

HI all,

I'm very pleased to say my Bongo just passed its MOT with nothing more than an advisory on a brake pipe :)

While all good on that front, I've noticed when I've been away that the sink water pump seems under powered, and the fridge doesn't seem to do much. I've been able to use the lights, and power/charge my phone and tablet, so it hasn't really bothered me.

I plan to do some longer trips in the new year, so am looking to replace the Leisure battery; I finally got round to testing it today and it's showing 10.5v under no load.

The current set up I have is:

Starter Battery
Yuasa YBX5335
YBX5335 12V 100Ah 830A Yuasa Silver High Performance Battery
Lead-Acid

Leisure Battery
Yuasa M26-80S Lead-Acid
YBX Active Marine Battery 12V 80Ah 600A
Lead-Acid

Split Charge Relay
Durite 0-727-70

The starter battery seems perfectly fine, I've had no issues starting.

I've done some research, and the impression I get is that I should be looking at a deep-cycle battery as a replacement, and preferably AGM technology?
I appreciate LiFePO4 is an option, but understand I would need a whole new split-charge setup for that.

The main question I have is, would the current split-charge setup be suitable if I was to replace the current leisure battery with an AGM. I'm considering something like this:

Powerplus LP100
Advanced AGM LP100 Leisure Battery 100ah 12v
https://advancedbatterysupplies.co.uk/p ... 100ah-12v/

Also, as far as I can see the current split-charge setup doesn't have any inline fuses, so wondered if it would be advisable to invest in a replacement kit while I'm at it, such as this:
https://www.ebay.co.uk/itm/136060951012 ... 5129060642

TIA
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Matt
95 2.5 Diesel, AFT, Side Conversion
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g8dhe
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Joined: Sun Apr 13, 2008 10:06 pm
Location: Worthing, West Sussex.

Re: Replacement Leisure Battery and Split-Charge Advice

Post by g8dhe » Fri Nov 07, 2025 5:41 pm

Yes the relay and current setup is fine for any type of Lead Acid battery, AGM is probably the best style, I've just had to replace mine and went for the https://www.tayna.co.uk/leisure-batteri ... ne/xv31mf/ which just fits under the bonnet on my tray but DO CHECK your dimensions width, depth and height as the battery trays all vary being non-standard in most cases.

The fuses will normally be close to each battery, they protect the wiring from each battery to the relay hence need to be close to the battery not close to the relay.
Geoff
2001 Aero V6, AFT, full side conversion.
UncleMatty
Apprentice Bongonaut
Posts: 8
Joined: Mon Mar 24, 2025 7:09 pm
Location: Edinburgh

Re: Replacement Leisure Battery and Split-Charge Advice

Post by UncleMatty » Fri Nov 07, 2025 10:15 pm

g8dhe wrote: Fri Nov 07, 2025 5:41 pm Yes the relay and current setup is fine for any type of Lead Acid battery, AGM is probably the best style, I've just had to replace mine and went for the https://www.tayna.co.uk/leisure-batteri ... ne/xv31mf/ which just fits under the bonnet on my tray but DO CHECK your dimensions width, depth and height as the battery trays all vary being non-standard in most cases.

The fuses will normally be close to each battery, they protect the wiring from each battery to the relay hence need to be close to the battery not close to the relay.
Hi Geoff,

Thanks very much for this. It's good to hear I will be fine with the charging setup. Thanks for sharing the battery info too, an extra 10Ah and a good price too. I will definitely check on the sizing. I am planning on picking up a new tray, as the DIY one that is in at the moment is showing its age. I found one on eBay that'll do 345mm x 200 x 230 which is just shy of the 240mm height of the one you shared, but will accomodate the one I've been looking at.

Thanks again :D
Matt
95 2.5 Diesel, AFT, Side Conversion
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