Has anyone figured out how to get to the bottom of what I can only describe as outrageous overstated specs on some of the top rated Lithium Battery Boosters for 2018?

Most specs suggest their product will turn over a specific Engine Size: "cu in" or "litres" plus indicate how many starts the product might provide on one charge ... useful? maybe, provided that all you want to use the product for is to be an emergency battery booster. Most of these products provide DC various accessory ports for charging and or powering most of your common toys ... in that respect, what I was looking for is the rated Ah capacity of these products ultimately to compare apples with apples

Noco has various models with all of them specifying Capacity in Joules (seem to have highest prices)
Gooloo suggests one of their products provides a Capacity of 20,000mAh (at 1/3 cost of Noco)
Beatit specify Capacities of 18,000mAh
Some noname brands are specifying Capacity in Wh
most brands appear to provide limited if any Capacity specs.

Given that most of these products appear to be approximately the same physical size and weight (in around 2-3lbs), my guess is they are likely to be using the same quantity of batteries with variations in the single cell capacities which normally rang from 600mAh up to as high as 2700mAh ... further, if a dedicated Smart Battery, Lithium Ion with a Capacity of 20Ah 12V battery weighs in between 5 and 7lbs how could these 1 to 2 lb devices manage to provide up to 20Ah of energy?

At best, without having one of these in hand, reading between the lines of the specs, I wonder if these products could provide any more then 4Ah of Capacity? Applying a weight ratio: 1.5 lb * 20Ah / 7lb = 4.3Ah

As a Sailor, I am looking for an alternative to carrying around heavy/huge SLA's to provide backup power to laptops and transceivers ... I am currently looking at a Smart 20Ah 12V Product but these boosters momentarily caught my eye with what appears to be a to good to be true specification???

Thoughts?

 

@bxdobs I see nobody has responded to your question. I think I'm even less qualified to answer than those who, before me, have not answered. So I'm wondering if you're confusing how many amps a battery booster can deliver. For instance, and I speak from ignorance, a 4Ah battery might be able to deliver 16 amps for 15 minutes. The WattHours is the same 4 amps in one hour, 16 amps in 15 minutes.

From what little I know about batteries, if a battery can deliver 4Ah then that's all you're going to get. I've seen people start cars using super capacitors. Can't tell you how many Ah's they hold, but the sudden max current available for the brief moment the engine is being turned over, a super cap can deliver more energy than a battery. It's just that they have very little reservoir to them.

The SLA is probably your best choice. Especially if it's a "Marine" battery, designed for deep cycling. Car SLA's don't like dropping voltages very low at all, and can be harmed if repeatedly taken to low voltages. The deep cycle battery (again from ignorance) can be discharged to a lower voltage than a car battery without suffering the same harm.

 

Methinks the booster makers are "slightly" exaggerating their product's capabilities.

The SLA is probably your best choice. Especially if it's a "Marine" battery, designed for deep cycling.

The problem with marine batteries is that they are not designed to deliver the high current required by a starter.

 

The Thread Starter said:

As a Sailor, I am looking for an alternative to carrying around heavy/huge SLA's to provide backup power to laptops and transceivers ... I am currently looking at a Smart 20Ah 12V Product but these boosters momentarily caught my eye with what appears to be a to good to be true specification???

I don't think he's looking to start a motor. And if sailing in the truest sense of the word, Sails, not motors is the key operative. If starting a motor boat (not something with a V8 engine) I'd have to imagine their starting needs are smaller. But I'm not a sailor, and the most experience I have with marine engines is an old aluminum Mercury that seized up. The starter on that was pretty small.

 

I don't think he's looking to start a motor.

True.
I missed where he said he wants it as backup power for electronics.

 

You are looking for a battery to turn over an engine ... this requires cells which can tolerate a very heavy drain . (high 'C' rating )..

This battery is 6 AHr... weighs less than than a pound , cost $25... can tolerate current of 40C that's 240A only for 1 minute before drained

If 240 amps is not enough buy two and put in parellel for 480A ... this is suitable for 12V systems