Trojan Battery Terminal Selection

[Keajre]

Dear Fellow Boaters,

Soon to purchase 4x Trojan T145's.  This will be configured in series (to go from 6v to 12v), and parallel (to go from 260AH @ C20 to 520 AH @ C20).  So should give me approximately 250 AH usable capacity based on a 20 hour discharge assuming a 50% DoD.  Will be having new cables made up.  There are a selection of different terminal posts available.  Since I am cabling from scratch I can choose the best post type for the project.  Would be grateful to get feedback and opinions please.

 

Will be a short cable run, probably 70mm cables running 1.5 metres to a 3kWH inverter.  The manufacture recommends x2 50mm2 cables for connections (two for positive and two for negative) .  That is on the basis that the inverter would be pulling its full load (6kWH burst, 3kWH continuous @ 25 degrees C) , which in reality will never happen.  Therefore, I plan to get one 70mm2 cable which should more than suffice.  Presently using some tatty old 35mm2 cable.

This is just additional information in case its helpful.

 

Many Thanks

 

 

Edited November 30, 2017 by Athy
extension

[dmr]

Given a free choice I would go for 1 or 2.

Do you have a free choice though?, most warehouses/battery suppliers probably only stock one terminal style (usually 1) so if you want something different there might be delays and extra cost.

On that subject, why not use the Trojan T105? it is the most popular Trojan battery so is readily available at a good price due to economy of scale. If you do a little calculation of amp-hours per £ I suspect the 105 will be a lot better than the 145.

..............Dave

[nicknorman]

19 minutes ago, Keajre said:

Dear Fellow Boaters,

Soon to purchase 4x Trojan T145's.  This will be configured in series (to go from 6v to 12v), and parallel (to go from 260AH @ C20 to 520 AH @ C20).  So should give me approximately 250 AH usable capacity based on a 20 hour discharge assuming a 50% DoD.  Will be having new cables made up.  There are a selection of different terminal posts available.  Since I am cabling from scratch I can choose the best post type for the project.  Would be grateful to get feedback and opinions please.

 

Will be a short cable run, probably 70mm cables running 1.5 metres to a 3kWH inverter.  The manufacture recommends x2 50mm2 cables for connections (two for positive and two for negative) .  That is on the basis that the inverter would be pulling its full load (6kWH burst, 3kWH continuous @ 25 degrees C) , which in reality will never happen.  Therefore, I plan to get one 70mm2 cable which should more than suffice.  Presently using some tatty old 35mm2 cable.

This is just additional information in case its helpful.

 

Many Thanks

 

 

I’m not sure it matters too much if you are going to get new cable made up. Personally I went for either 1 or 2, can’t remember! I don’t particularly like the Automotive post type (3)  and for 4 you will have a separate nut and bolt instead of just a nut.

4 minutes ago, dmr said:

Given a free choice I would go for 1 or 2.

Do you have a free choice though?, most warehouses/battery suppliers probably only stock one terminal style (usually 1) so if you want something different there might be delays and extra cost.

On that subject, why not use the Trojan T105? it is the most popular Trojan battery so is readily available at a good price due to economy of scale. If you do a little calculation of amp-hours per £ I suspect the 105 will be a lot better than the 145.

..............Dave

Seem to be very similar price in fact - £0.65 per AH for the 145s, £0.62 for the 105s.

[dmr]

7 minutes ago, nicknorman said:

I’m not sure it matters too much if you are going to get new cable made up. Personally I went for either 1 or 2, can’t remember! I don’t particularly like the Automotive post type (3)  and for 4 you will have a separate nut and bolt instead of just a nut.

Seem to be very similar price in fact - £0.65 per AH for the 145s, £0.62 for the 105s.

I stand corrected and suitably humbled!  I did do this calculation when I got my last set of T105s and I thought there was quite a difference, but it was a few years ago.

Prices have shot up recently so I assume the 105's have increased by a bigger factor.

..............Dave

[WotEver]

I’d go for 1) or 2). 

[rusty69]

Just now, WotEver said:

I’d go for 1) or 2). 

Surely you and Nick are not in agreement? Sorry wrong thread!

[smileypete]

Just to backpedal a bit...

Somewhere in another topic I suggested three main scenarios for batt ownership:

    Plan A for most (95%?) of boaters would be decent brand leisure batts.

    Plan B would be Trojans but only if they can be provided with the correct charge and EQ voltages, and required maintenance and monitoring. I expect this needs a genuine long term interest in batteries, hmmm...

    Plan C is to use a less common battery make/type/chemistry/desulphators etc, but then you may be the guinea pig on that one.

I guess most second home type boats fall into Plan A, and most off grid liveaboards move towards Plan B at some point.

So...

If you're really set on Trojans, how do you plan to charge and equalise them to the required voltages, and how do you tell when to charge then and when they are fully charged?

Edited November 28, 2017 by smileypete

[WotEver]

1 minute ago, rusty69 said:

Surely you and Nick are not in agreement? Sorry wrong thread!

Nick and I are in agreement on most things

Once he stops fannying around with theory and looks at the facts, we’ll agree over Peukert too

[nicknorman]

18 minutes ago, dmr said:

I stand corrected and suitably humbled!  I did do this calculation when I got my last set of T105s and I thought there was quite a difference, but it was a few years ago.

Prices have shot up recently so I assume the 105's have increased by a bigger factor.

..............Dave

They certainly used to be much cheaper, but not now it seems.

[Detling]

I would query the 70mm for the inverter my cable calc shows 0.5 volt drop for that 3meter run (1.5 each way) it recommends 90mm. that is for 300 A  so not quite full chat. I appreciate that you will have the engine running with a big alternator so not all amps come from the battery, but they all go up the feed and return.

[Tony Fuller]

When selecting battery cable sizes don't forget about 'heat'. Battery cables do tend to get very hot when passing high charging currents.

I have 90mm cables feeding into twin battery banks & they will burn your hands after passing 130 amps for half an hour.

So apart from the voltage drop question, the bigger the better.

I used multi strand welding cable for battery wiring, it is easy to use & bends nicely.

Tony

[Keajre]

15 hours ago, dmr said:

Given a free choice I would go for 1 or 2.

Do you have a free choice though?, most warehouses/battery suppliers probably only stock one terminal style (usually 1) so if you want something different there might be delays and extra cost.

On that subject, why not use the Trojan T105? it is the most popular Trojan battery so is readily available at a good price due to economy of scale. If you do a little calculation of amp-hours per £ I suspect the 105 will be a lot better than the 145.

..............Dave

Thanks Dave, I have emailed Tayna.co.uk to ask.  You at probably right, depends on what they stock.  Yes I had heard T105 was better value for money, but will address this in the below thread as its an interesting point.

 

 

15 hours ago, nicknorman said:

I’m not sure it matters too much if you are going to get new cable made up. Personally I went for either 1 or 2, can’t remember! I don’t particularly like the Automotive post type (3)  and for 4 you will have a separate nut and bolt instead of just a nut.

Seem to be very similar price in fact - £0.65 per AH for the 145s, £0.62 for the 105s.

I agree, based on the default 20 hour AH rate.  I am sure there was a bigger gap between them previously, so this is good to see and an important consideration.  Thank you

[Keajre]

14 hours ago, WotEver said:

I’d go for 1) or 2). 

Ye I agree, I am thinking 2, with the longer post, could be useful, 7mm higher

[Keajre]

15 hours ago, smileypete said:

Just to backpedal a bit...

Somewhere in another topic I suggested three main scenarios for batt ownership:

    Plan A for most (95%?) of boaters would be decent brand leisure batts.

    Plan B would be Trojans but only if they can be provided with the correct charge and EQ voltages, and required maintenance and monitoring. I expect this needs a genuine long term interest in batteries, hmmm...

    Plan C is to use a less common battery make/type/chemistry/desulphators etc, but then you may be the guinea pig on that one.

I guess most second home type boats fall into Plan A, and most off grid liveaboards move towards Plan B at some point.

So...

If you're really set on Trojans, how do you plan to charge and equalise them to the required voltages, and how do you tell when to charge then and when they are fully charged?

Well I used to a Plan A boater, 4 years of budget quality batts.  Also taken me 4 years to really appreciate battery chemistry and how to treat them.  The 1st set were lorry starter batts (yes oh dear), this is when I bought the boat.  They were shot already.  So I bought 3 cheapies, 110 AH leisure's, but I discharged them too much.  Down to 11.6 volts, cringe at the thought now looking back.  

So I am ready for Plan B.  I have a Victron Inverter / Charger which I can configure with my laptop with all the correct voltages for Bulk charge, float and equalization.  The only thing I cannot quite accommodate is the 16.2 equalization charge stipulated by Trojan in the manual (screenshot below).  My Victron just elevates the voltage based on the absorption voltage by 1v.  So in this case that would result in an equalization voltage of 15.8.  Don't plan on equalizing too often as if degrades the plates, having said that is it different with traction batteries? I presume you equalize based on the hydrometer reading after a full charge (well after full charge and then 12 hour wait)

The main benefit in my mind of going with 145s instead of 125s is that the extra AHs will mean I can avoid discharging them below say 70% (maybe 12.4 approx.).  This means the plates will gather far less sulphur and should last much longer. The method of checking the charge will be voltage after 24 hours rest, and by using a hydrometer.  Personally I love wet lead acid and I enjoy maintaining them.  I'm the kind of guy that does bar graphics of the specific gravity / strength of the sulphuric acid in Excel.  Shouldn't admit that, but its true.  Then I can see how fast they at degrading over time.  

When I am out cruising I will use my 2.5kWH generator so that the Charger will perform the proper step charging phases, wont be relying just on the alternator as this is very ineffective unless you have  smart charger, and I don't have one.  I also have 250 watts of solar with an MPPT reg.

 

Cheers

 

Edited November 29, 2017 by Keajre

[nicknorman]

Ive never taken my Trojans above 16v. 15.5v is fine for equalising in summer (though rarely necessary) and 16v for winter.

[Keajre]

12 hours ago, Detling said:

I would query the 70mm for the inverter my cable calc shows 0.5 volt drop for that 3meter run (1.5 each way) it recommends 90mm. that is for 300 A  so not quite full chat. I appreciate that you will have the engine running with a big alternator so not all amps come from the battery, but they all go up the feed and return.

Isnt 70mm2 cable so thick its very hard to bend?

[rusty69]

2 minutes ago, Keajre said:

Isnt 70mm2 cable so thick its very hard to bend?

70mm2 welding cable is quite flexible. 

[Robbo]

5 minutes ago, rusty69 said:

70mm2 welding cable is quite flexible. 

I use OceanFlex cable for my battery cable and it's very flexible and would recommend. - http://www.iem-services.co.uk/search.asp?types=yes&type=CABLE+-+TINNED%2FMARINE+>+BATTERY+CABLE+''OCEAN+FLEX''

[nicknorman]

15 minutes ago, Keajre said:

Isnt 70mm2 cable so thick its very hard to bend?

No, especially if you get the welding cable type with multiple thinner strands. Very flexible.

[Keajre]

3 hours ago, Robbo said:

I use OceanFlex cable for my battery cable and it's very flexible and would recommend. - http://www.iem-services.co.uk/search.asp?types=yes&type=CABLE+-+TINNED%2FMARINE+>+BATTERY+CABLE+''OCEAN+FLEX''

Great, thanks for the link,  where / who did you get to do the crimping?  Hydraulic crimp presses for 70mm2 are pretty expensive to do it yourself. 

[rusty69]

3 minutes ago, Keajre said:

Great, thanks for the link,  where / who did you get to do the crimping?  Hydraulic crimp presses for 70mm2 are pretty expensive to do it yourself. 

About 20 quid on fleabay.

[Robbo]

5 minutes ago, Keajre said:

Great, thanks for the link,  where / who did you get to do the crimping?  Hydraulic crimp presses for 70mm2 are pretty expensive to do it yourself. 

I use my own Hydraulic crimper, about £25-40 on ebay..   I tend to use a size below on the crimp, but the correct size lugs.

https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313.TR12.TRC2.A0.H0.XHydraulic+crimper.TRS0&_nkw=Hydraulic+crimper&_sacat=0

 

I would also recommend using adhesive lined heatshrink as well to finish off. http://www.iem-services.co.uk/search.asp?types=yes&type=HEATSHRINK+SLEEVING+>+3-1+Adhesive+Lined

Edited November 29, 2017 by Robbo

[Keajre]

1 minute ago, Robbo said:

I use my own Hydraulic crimper, about £25-40 on ebay..   I tend to use a size below on the crimp, but the correct size lugs.

https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313.TR12.TRC2.A0.H0.XHydraulic+crimper.TRS0&_nkw=Hydraulic+crimper&_sacat=0

Ye I was about to reply, its above 70mm2 that gets expensive I think.  I used a 50mm2 crimp once, didnt look very neat when I did it.  Might be better to get it done professionally.

Trojan seem to suggest the crimping alone isn't sufficient:

Any thoughts?

 

[rusty69]

7 minutes ago, Robbo said:

I use my own Hydraulic crimper, about £25-40 on ebay..   I tend to use a size below on the crimp, but the correct size lugs.

https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313.TR12.TRC2.A0.H0.XHydraulic+crimper.TRS0&_nkw=Hydraulic+crimper&_sacat=0

 

I would also recommend using adhesive lined heatshrink as well to finish off. http://www.iem-services.co.uk/search.asp?types=yes&type=HEATSHRINK+SLEEVING+>+3-1+Adhesive+Lined

I notice Trojan recommend soldering too, but thought this was frowned on

WP_BatteryCableGuide_0512.pdf

 

Cross posted

Edited November 29, 2017 by rusty69

[Keajre]

4 hours ago, Keajre said:

Thanks Dave, I have emailed Tayna.co.uk to ask.  You at probably right, depends on what they stock.  Yes I had heard T105 was better value for money, but will address this in the below thread as its an interesting point

 

Ye, Tayna.co.uk replied and they only supply ELPT terminals, shame, wanted EHPT

7 minutes ago, rusty69 said:

I notice Trojan recommend soldering too, but thought this was frowned on

WP_BatteryCableGuide_0512.pdf

 

Cross posted

Ye the screenshot above is from that same PDF.  So, crimp it, then just add solder using a standard solder iron?