B2B would there be any advantage for me

[OllyHughes]

I have a 1997 Fiat based autotrail, all old tech, all working as it should. My question is could I improve leisure battery charging if I fitted B2B instead of split charging, bearing in mind i don't have a smart alternator. My understanding is that I wouldn't gain much if anything. Any advice would be most welcome

 

[nicholsong]

My Battery monitor tells me that when the engine first starts 20A are being delivered to 2 batterys, this drops off as the batteries charge, which is what you would expect. The way we use the van has changed as i get older, we used to stay a few days and move on, but we now tend to stay in one place for longer periods, some times we use EHU many times we don't and rely on solar to top up the batteries, if the sun shines that fine, if not we have a problem,as was the case last summer. It took 200 miles of driving before the batteries were up to 85%, which promted me to think about B2B. I think I will do as you suggestand beef up the wiring and the relays and see what effect that has and go from there. Thanks for your input

I think the reason for the drop-off in charge is that the set-up of the base van is that the standard voltage regulator is wired in to drop the alternator charge when the engine battery is topped-up, but the domestic batteries have not reached the same charge.

This is the problem that B2Bs are designed to overcome, by bypassing the standard voltage regulator and fooling the alternator into continuing to give a high charge rate to the domestic batteries.

Unless the cost of a B2B is beyond reach I would fit one straight away.

We are never on EHU and only have a 80w solar panel. We find that with the B2B we only have to run 1/2 to 3/4 of an hour to top- 1-2 days battery use, not 200 miles, but we do not use much electricity. Of course we may have a bigger alternator - I think ours is 80A.

Geoff

 

[RM_Marine]

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[OllyHughes]

I think the reason for the drop-off in charge is that the set-up of the base van is that the standard voltage regulator is wired in to drop the alternator charge when the engine battery is topped-up, but the domestic batteries have not reached the same charge.



Geoff

Thanks for that, something to think about

 

[OllyHughes]

We are never on EHU and only have a 80w solar panel. We find that with the B2B we only have to run 1/2 to 3/4 of an hour to top- 1-2 days battery use, not 200 miles, but we do not use much electricity. Of course we may have a bigger alternator - I think ours is 80A.

Geoff

Can I ask what size B2B you have fitted and the AHC of the batteries being charged
Thanks

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[mitzimad]

The question stems from a 3 week trip, no EHU, the first 2 weeks the sun shone so the solar kept the btys topped up, the final week no sun so btys very low, it took over 200 miles driving to fully charge them. Which made me think about B2B. If went down this road i would fit 30A charger as i doubt my alternator puts out much more

in that scenario yes a b2b would be better

 

[OllyHughes]

Hello folks. I've resurrected this thread to save time and so I don't need to rehash it. I decided to opt for a B2b charger
VCC 1212-30 Input Voltage 12 V Charging Capacity 12 V / 30 A. I have upgraded the cabling and every thing is in situ ready to be connected, exept for one thing. How do I connect the 12v side of the fridge to the B2B controler when I disconnect the split charger from the alternator. It must have a 'simple' solution .I would be grateful for any help. Thanks

 

[autorouter]

Hello folks. I've resurrected this thread to save time and so I don't need to rehash it. I decided to opt for a B2b charger
VCC 1212-30 Input Voltage 12 V Charging Capacity 12 V / 30 A. I have upgraded the cabling and every thing is in situ ready to be connected, exept for one thing. How do I connect the 12v side of the fridge to the B2B controler when I disconnect the split charger from the alternator. It must have a 'simple' solution .I would be grateful for any help. Thanks

I'm sure there is a simple solution, but it depends on the details of how everything is connected in the existing setup. Is there a control panel and fusebox, or maybe just a fusebox with some relays separate? Ideally you can disable the split charge relay without losing any of the other functions. I think a picture of the area around the split charge relay might help.

 

[msyd]

Going back to earlier posts, our Delaware has 20A fuse for the leisure battery, so you'll never see anywhere near 20A going into or out of the LB. So if you add a B2B (I added a 60A Sterling) you'll need much heavier cables and a separate fusing system. Apart from disabling the split charge relay (which you can do with another relay, operated by the D+ signal) you can leave all the factory wiring as-is.

 

[OllyHughes]

I'm sure there is a simple solution, but it depends on the details of how everything is connected in the existing setup. Is there a control panel and fusebox, or maybe just a fusebox with some relays separate? Ideally you can disable the split charge relay without losing any of the other functions. I think a picture of the area around the split charge relay might help.

The split charge relay/relays are next to the vehicle battery under the bonnet, 1 for the charging system, and 1 for the fridge nothing very complicated, I can disable either circuit by simply removing the relays, which is what I am intending to do when every thing is in situ for the B2B thereby leaving the factory wiring as it is. I'm wondering if I can leave the relay for the fridge as it is, and not wire it into the B2B unit, which would make my life much simpler. If not it means rewiring the fridge to connect to the B2B control unit D+and a relay. I hope that makes sense

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[OllyHughes]

Going back to earlier posts, our Delaware has 20A fuse for the leisure battery, so you'll never see anywhere near 20A going into or out of the LB. So if you add a B2B (I added a 60A Sterling) you'll need much heavier cables and a separate fusing system. Apart from disabling the split charge relay (which you can do with another relay, operated by the D+ signal) you can leave all the factory wiring as-is.

I have upgraded the wiring for the charging system to 16mm along with the necessary fuses. My problem is the fridge, the charging relay and the fridge relay are side by side next to the vehicle battery under the bonnet, I'm wondering if i can leave the fridge circuit as-is while upgrading the charging circuit

 

[Itsmcb]

I have upgraded the wiring for the charging system to 16mm along with the necessary fuses. My problem is the fridge, the charging relay and the fridge relay are side by side next to the vehicle battery under the bonnet, I'm wondering if i can leave the fridge circuit as-is while upgrading the charging circuit

I have the similar old two relay system. I can't see any reason you can't leave the fridge relay working as normal. The wiring is completely separate for fridge and charging. To check, just pull the charging relay and see if the fridge still works?

 

[OllyHughes]

I have the similar old two relay system. I can't see any reason you can't leave the fridge relay working as normal. The wiring is completely separate for fridge and charging. To check, just pull the charging relay and see if the fridge still works?

Thanks, the obvious thing to do really. Ive been seriously over thinking the problem