bs3911 compared to CCA for starter batteries
- Thread starter geem
- Start date
Refueler
Well-Known Member
Lithium batterys are capable of extreme power delivery BUT care must be taken to ensure the C rating is high enough. The problem actually for Lithium is not so much the cells (as long as C rating is high enough) - but the power leads and their ability to handle the loads.
Poey50
Well-Known Member
Delivery of a burst of high amps isn't LFP's strong suit and the limitation will be the capacity of the BMS which may not be high on drop-ins. It can be done but there is a reason that most people fitting LFP stay with lead acid for starting.
geem
Well-Known Member
I could replace one but I know from the last time that the second one failed only a month or 2 later. I have battery balancers on the batteries so mismatched batteries aren't really a problem. It's convenient to change them both now.
440cca isn't equivalent to Perkins BS 440. That's the reason for the post. I believe I need far more than 440cca. My guess is between 550 and 750 CCA each.
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Zing
Well-Known Member
There are many superior characteristics of lithium batteries and many that would apply in this situation. Longer life, so lower cost in the long run. Higher peak current discharge capability, so easier starting. Near zero peukert factor so easier starting. Almost no voltage drop, so faster engine turning and easier starting. Half the weight maybe - it all helps, even in a heavy cruiser. Zero maintenance compared to flooded, but less so vs AGM, where the cost disadvantage is less. Probably some more points. To be sure you don’t need one, lead works. I don’t have one yet for starting as my old ones work still, but will certainly think about it on replacement.
Zing
Well-Known Member
Yes, you would need one without an overcurrent monitoring BMS. That done with LFP the max discharge is far higher like for like.
Zing
Well-Known Member
Easy to fix.
geem
Well-Known Member
Where do you get this miracle lithium battery that can take the huge inrush current of starting a 4 4 litre diesel? People have enough problems finding drop in replacement lithium that will run windlasses, inverters and bow thrusters. I would be surprised if your miracle battery even exists
Tranona
Well-Known Member
Modern diesels start easily. I have had 2 Volvo 30hp and now a Beta 30. They all start instantly and then within minutes are fully recharged. Lithium is really a waste for this simple application. No need for deep discharging and quick recharging - the 2 great advantages of Lithium for use on a boat - but for domestic loads. As for weight, the Odyssey that I have ( in the right in post#16) weighs 9.5kgs.
I have yet to see a lithium battery recommended for engine start - they all emphasise that they are for deep cycle applications - and none I have looked at quota CCA - the critical measure for engine start. As for life, as i noted earlier the Red Flash in my Morgan did well over 19 years. Typical cycle for AGMs are around 2000, (compared with 3000 for lithium), although start cycles are very low discharge,
Horses for courses - best to identify the requirements for the application and match with the properties of the alternate products on offer.
PaulRainbow
Well-Known Member
Using Lithium to start engines is just nuts.
Can lithium battery be used as start battery?
There are some that claim to be suitable for engine starting: Antigravity H6/Group-48 Car Battery
£1,139 for a 60ah battery!!
A SLA engine starter battery for the typical small engined yacht costs about £50 and will last at least 5 years, most likely much longer. £1,139 will buy 22 SLA batteries. with a few coppers change. That's at least 110 years of engine starting !!!
Can lithium battery be used as start battery?
There are some that claim to be suitable for engine starting: Antigravity H6/Group-48 Car Battery
£1,139 for a 60ah battery!!
A SLA engine starter battery for the typical small engined yacht costs about £50 and will last at least 5 years, most likely much longer. £1,139 will buy 22 SLA batteries. with a few coppers change. That's at least 110 years of engine starting !!!
PaulRainbow
Well-Known Member
A pair of circa 450/500 CCA batteries might get you by, but, i'd still measure the existing batteries and look online to see what the CCA and Ah ratings are. .
PaulRainbow
Well-Known Member
The manual here: https://s7d2.scene7.com/is/content/Caterpillar/C10529242
Page 52 states : " Two 12V batteries in series, each 520 Amps BS3911 or 800 Amps SAE J537 "
That's for temps down to -15c.
From the Yuasa site:
SAE (J537 Jun 1994 American Standard)
This is the starting test according to the SAE (Society of Automotive Engineers). The test specifies that the battery at a temperature of –18°C will deliver a current equal to the Cold Cranking Amps for 30 seconds with the voltage staying above 7.2 volts (3.6 volts for a 6 volt battery).
Although subject to battery design, an approximation of SAE to DIN CCA relationship is:- SAE = (DIN x 1.5) + 40.
Battery performance drops off quickly with temperature, so this test is a good check of a battery’s starting ability. With a 10 second voltage of EN rating and its need to support 30 seconds to 7.2V, the SAE test gives a good view of high rate capacity capability of the battery.
I'd still measure the existing batteries
Page 52 states : " Two 12V batteries in series, each 520 Amps BS3911 or 800 Amps SAE J537 "
That's for temps down to -15c.
From the Yuasa site:
SAE (J537 Jun 1994 American Standard)
This is the starting test according to the SAE (Society of Automotive Engineers). The test specifies that the battery at a temperature of –18°C will deliver a current equal to the Cold Cranking Amps for 30 seconds with the voltage staying above 7.2 volts (3.6 volts for a 6 volt battery).
Although subject to battery design, an approximation of SAE to DIN CCA relationship is:- SAE = (DIN x 1.5) + 40.
Battery performance drops off quickly with temperature, so this test is a good check of a battery’s starting ability. With a 10 second voltage of EN rating and its need to support 30 seconds to 7.2V, the SAE test gives a good view of high rate capacity capability of the battery.
I'd still measure the existing batteries
Tranona
Well-Known Member
Yes, the 30Ah version is £900 - nearly 6 times the price of the similar capacity Red Flash I have just bought for the Morgan tayna.co.uk/car-batteries/red-flash/750/ which lasted 19 years
PaulRainbow
Well-Known Member
Buy the Lithium, you'll be breaking even in 114 years ?
Tranona
Well-Known Member
Now, there's n incentive to try and live longer! Did question the "investment" in the Red Flash as it will almost certainly outlast me, but not the car so my grandchildren can benefit.
geem
Well-Known Member
Last batteries were a 'buy what you could get' solution in Colombia. I have two miss matched batteries as a result. The previous one came from Panama on a similar basis. It's easy to forget how well supplied the UK is for stuff we all take for granted. In the third world it's a completely different experience.
If I was in the UK I would fit some AGM stop start batteries. I have of those for the generator. They are not expensive in the UK. Here they are unobtainable. Even crappy batteries here are twice the price of UK.
fushion julz
Member
I have a 24V system on my Perkins T6.354
I use a pair of Exide ER550 batteries as starter power....760A CCA & 115Ah
I use a pair of Exide ER550 batteries as starter power....760A CCA & 115Ah
Refueler
Well-Known Member
Only on Lithium banks designed for such work. Where basically standard Lead Acid Style casing used so that heavy duty cables can be connected. Outside of that design - you'd be hard to find suitable and definitely not an easy fix.
Refueler
Well-Known Member
Until locally they stopped selling 2nd hand batterys from crashed cars ... I always bought those. They all lasted more than 4 years .. in fact the last set I bought from Breakers Yard on Hayling Island around 2004 (ceased trading years ago) were still going strong in 2007 when boat came to Latvia. Replaced about 2012 ish .... next set of 2nd hand lasted till about 2019 ... when a power failure to the boat allowed the charge to drop and they froze during the -25C ....
Present set are one new battery and one 2nd hand ....
My reasoning being that the cost of such .... was about 20 - 30 euros for a 80 to 100A/hr .... I could buy 2 or 3 for price of a new branded one. AND still get decent life out of it.
Present set are one new battery and one 2nd hand ....
My reasoning being that the cost of such .... was about 20 - 30 euros for a 80 to 100A/hr .... I could buy 2 or 3 for price of a new branded one. AND still get decent life out of it.
Zing
Well-Known Member
No, it’s not nuts. You are over arguing your position. If initial expense is the priority then sure, they are no use. If other things are important like whole life cycle cost including hassle and reliability risk issues then just from a cost perspective they are awash. Then you have the other advantages I pointed out.
If it’s nuts to start engines with them then why do Ducati and Aprilia amongst other manufacturers fit them as standard to their motorbikes?
I think four of these would be a good choice. Note $ 212 not £1,139 and if you want the hassle they are available delivered direct from China for a quarter less. I bought something similar.
WINSTON WB-LYP40AHA LiFeYPO4, 3.3V, 40Ah | shop.GWL.eu
