Bully Boy Battery Cables. 8th November

(Tech Post by Mick)

When I installed the new LiFePO4 lithium batteries back in the spring of this year, I had ordered cables that were too long. Better too long than too short! At the time, I didn’t have the right tool for cutting the big chunky cables (35mm²) nor a tool to crimp new terminals onto shortened cables. In my 40 year career in telecoms and IT, I didn’t work with thick wires, the wires I normally dealt with were only 0.2mm². So I left the battery cables long and tucked the surplus away in a corner of the engine bay.

Monitoring the charging of the batteries over the summer I noticed that the batteries rarely get above 27.3 volts while charging from the alternator and the current, whilst it starts off high at 80 amps or so, quickly drops to 30 amps and stays there for hours. The domestic alternator on Oleanna is a Beta original 24 volt 100 amp. Here is an example from a long day (for us) cruising. Ignore the big downward spikes, they are where we put the kettle on.

My suspicion is that the charging specification of the alternator doesn’t get up to the 28.4 volts that are required to quickly fully charge LiFePO4 batteries. But that is more complicated to deal with so as a first step I thought I’d shorten the cables. I purchased a pair of cutters and a crimping tool as well as some terminals. Tools (and pictures) from https://www.12voltplanet.co.uk/

Equipped with these tools I took a train ride down to Goole. I turned off the inverter and disconnected the incoming 230v supply. I turned off all the DC systems at the isolators. Both domestic batteries got disconnected at the terminals and from the positive bus bar. I pulled back the spare cables from the engine bay to the inside battery that is located in a cupboard just through the bulkhead, measured how much I needed to connect, took the plunge and cut the cables. I took just under a metre or so off each cable.

Time to repeat for the negative cable.

It was then on to the battery in the engine bay. The same length of each cable was cut off, stripped back, terminal applied, crimped, and heat shrunk.

I reconnected all the cables, thought about things for a while and turned everything on. No smoke or sparks so that was good.

The engine was started while I monitored the current going into the batteries.

The values were slightly higher than before but not hugely. Time will tell but for now that will do. I am going to investigate external alternator regulators to try to boost the charging voltage. A Mastervolt Alpha Pro III is top of the list but further investigation is required. I’m also wondering if I shouldn’t get a marine electrician to look at it and do the job.

Time to pack up and go home.

Oleanna tucked up in the marina

Since last posting we have enjoyed bonfire night in Scarborough. I, Pip now, have spent many of the last six years being busy on panto, normally painting the floor. Only able to hear the occasional pop bang whizzzzzzz of fireworks from Chippy stage, so this year I was determined to see some.

Scarborough has a tradition that people light fires on the beaches and along with that come fireworks, no need to go to the organised display. So we caught the Coastliner bus to Peasholme Park and walked down to the Corner to see how much beach close to high tide had left in the North Bay.

Freddie on Bonfire Night

There were hundreds of people, several fires all huddled onto the 20ft of sand. Plenty of people had fireworks, just how much do they spend?! But it did mean we got quite a good display once we’d decided to move away to a safer distance. There seemed to be a bit of a duel going on between the bottom of the castle cliff and up by the beach huts, We stopped to say hello to Freddie and check he was alright, before walking around Marine Drive where fishermen sat on the accropodes with head torches and luminous lines on their rods.

The South Bay with the Grand Hotel in the background

Round in the South Bay there was more beach with a huge fire. People huddled round as others set up rockets facing out towards the sea, a bit more of a comfortable space and the road to be able to watch from. The beach was strewn with spent fireworks, just how much had gone up in glittering whizzing bangs? Certainly none of them had come from the sort of selection box I grew up with. The Scarborough seafront more than made up for the last few years.

Quotes have been coming in for house and boat jobs. Most of them twice what we thought they’d be. Some careful consideration will be needed before we make our minds up.

The cavolo nero has lasted us over a week

Veg boxes have started again.

Mick has been tidying up the garden and making use of some two year matured compost, we’ll see how the wild flowers like it.

A visit to the Stephen Joseph Theatre to see The Whitby Rebels, the true story of Captain Jack Lammiman who took a crew of unlikely misfits on a voyage to the Arctic. Three of the actors are old friends so it was great to see them, they had the better parts in a show that we weren’t too convinced about, it felt as though several ideas had been put together and none of them managed to take the lead. But it’s a local story and the audience seemed to enjoy it along with the huge set.

Just a few ingredients!

A day was spent in the kitchen, a second go at the chicken, leek, ham dauphinoise pie. This was tasty but as I’d used soya cream it was nowhere near as tasty as when I’d used double cream. I’ll write the recipe up if anyone fancies a go at this self indulgent pie!

Left to Right.
Mary Berry crunchy top, yummy pie, River Cottage GF super nice lemon drizzle cake

There was to be a Leckenby get together and my job was to do pudding. A request was made that there should be a takeaway version for Josh to take back to University. So one gluten free posh lemon drizzle cake and a gluten filled lemon crunchy topped cake for Josh were made.

We caught the Coastliner across to York where we got a full tour of the London Leckenby’s holiday let that they have invested in this year. Andrew and I grew up in York and it’s been 11 years since we sold our family home, so it’s rather nice to be able to meet up in the city once again. Andrew and Jac have been taking advantage of gaps in bookings to have a few days in York and putting their mark on the flat. Standard pictures of York have been replaced with pencil sketches Dad did of the bar walls, I may even sneak in a painting of my own.

Set to work!

The letting agents had advised them to deck the flat with Christmas cheer as guests expect such things from now until Christmas, so illuminated trees were already in position. Left over baubles were handed over to me to make a wreath for the flat door, good job I’d taken my glue gun with me expecting I’d be given a making job.

Lovely Salad

A leg of lamb was enjoyed along with lots of wine to celebrate us all being together in York. Plans are afoot for a special get together next year, we may bring our own accommodation on Oleanna, though. The sofa bed was okay but has been put higher up the list of things to be replaced in the flat, we’d been guinea pigs. A lovely evening with the London Leckenbys and a very early start to Christmas. I hate to think what Granny would have thought!

Hello!

0 locks, 0 miles, 2 trains, 4 shorter cables, 2 bays of fireworks, 3 buses, 1 very wide boat, 2 boxes of things for Oleanna, 1 wreath, 2 lemony cakes, 1 special pie, 1 Leckenby get together, 1 river view, just.

14 thoughts on “Bully Boy Battery Cables. 8th November

  1. Tom

    Mick my 36V lithium battery has a 48V charger. I think your charging voltage is too low. It should be charging at 29.2V and Rested at 27.2V. Float is 27V. Looking at the size of your cables I don’t believe they are causing voltage drop. Your charge doesn’t show the % SOC. However if the batteries were already at 80% then 27.2 – 27.5V is close to correct.

    Reply
    1. Pip Post author

      I agree with you Tom. I didn’t expect the shorter cables to fix things but it was worth a try, not least to get rid of the surplus cable in the engine bay. I don’t think the Beta alternator puts out enough voltage. I also think that it’s not a faulty alternator but this is its spec. I’m pretty sure an external alternator regulator will be required.

      Mick

      Reply
  2. Barbara

    What a lovely surprise this morning to see your blog I love reading it while having my coffee. We replaced our batteries when we bought Jack we got AGM’s a bit pricey but we had them on the other boat and had no problems with them so decided to do the same. Hope you are both well thank you for saying hello to Scarborough for me. Take care xx

    Reply
  3. Brian Anthony Holt

    I would be very surprised if the terminal voltage of the batteries gets to 28Volts while charging, The load on a standard alternator will suppress the voltage. mine don’t hit that voltage until the BMS stops the charge. I also find that engine speed makes a bid difference in charge rate. It may be worth measuring the voltage on the back of the alternator and comparing it with the battery terminals while they are charging hard.

    Reply
    1. Pip Post author

      Thanks Brian. I did measure the voltage at the alternator a while back but I can’t now remember the results. I’ll do it again next time I’m down at the boat. The BMS is programmed to disconnect at 28v but it never gets there. I get an individual cell over voltage shutdown (at 3.5v) before the whole battery gets to 28. It takes ages though, like many hours of cruising. On initial startup I can see the alternator putting out 80 amps, even at idle speed, but within 10 minutes or so it drops to about 30 to 40 amps, even at cruising on the River Trent revs. On the 12v boating group on FB the suggestion is that a LiFePO4 will take all that the alternator can give until pretty much fully charged. Ours doesn’t do that but quickly drops to 30 amps or so then slowly drops even further down to between 5 and 10 amps. At that point the BMS cell overvoltage kicks in and shuts down the charging. Incidentally the bow thruster bank of 2 x 12v LA batteries (in series) is wired in parallel with the LiFePO4s. The bow thruster bank isn’t wired through the Victron shunt so some of the current will be going there. But the Victron monitor and the individual BMSs don’t show much difference in current draw.
      Mick

      Reply
  4. Dave (Scouts)

    Just printed the leek pie and will try during the week.

    As Mick bought the tools from 12vplanet, drop them an email and ask about charging. They are quite knowledgeable. They may recommend a battery to battery charger to boost your charge rate.

    Ps
    We walked around chippy today and went past the theatre but no photos as not open at the time.

    Reply
    1. Pip Post author

      Hope you like the pie.
      Saw that you’d been to Chippy. Suspect everyone was sleeping off the party after press night yesterday before a 2 show day!
      Should Mick and I now be watching Inspector Morse?

      Reply
      1. Dave (Scouts)

        Yes. Morse. Lewis then Endeavour.
        However Ludwig on BBC recently was very good. A cross between Morse and death in paradise

        Reply
        1. Pip Post author

          Tradition has it that we watch a couple of episodes of Morse once I’ve finished panto. Might watch a few over the next couple of days.
          Yes we enjoyed Ludwig, good puzzle solving as well as the murders!

          Reply
  5. Caroline Brent

    Hi Mick Ed Shears fitted our Alpa pro, for our Beta 43 24v, we are over the moon with the charging, he did a fantastic job and would recommend speaking to him/asking if he can do the job, caroline and Martin

    Reply

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