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New Product: The 4S 15.6Ah Lithium Ion Battery for the BlueROV2!

Originally published at: New Product: The 4S 15.6Ah Lithium-ion Battery for the BlueROV2! - Blue Robotics

Today we’re excited to announce a new product: the 4S 15.6Ah Lithium Ion Battery for the BlueROV2.


Unlike most of our products, this is one we never planned to make! We have the original lithium ion battery (with black wrapper) that does a perfectly great job of powering the BlueROV2 through long and tough missions. Those batteries are powering thousands of ROVs around the world!

So why a new battery, you ask? If you haven’t noticed, that original battery has been out of stock for a few months. That’s due to some craziness in the world’s supply chains right now – alongside the electronic chip shortages that have crippled many factories, there is a shortage of lithium ion battery cells. This problem has been getting worse and worse for us since 2020. At first, we were still able to get small quantities of Samsung 30Q cells, but at more than double the original price. We bought up all the cells we could find at that price, but now, we’re not able to get them at all, so we’ve had to pursue other options!


The new battery (left, white) and the original battery (right, black).

The new 4S 15.6Ah Lithium Ion Battery (with a white wrapper) is nearly identical to our original battery, but it uses a different cell: the Molicell P26A. This is one of the few high-discharge cells we’re still able to get at the moment. The resulting battery pack has the same discharge rating as the original battery, but a slightly lower capacity of 15.6Ah versus 18Ah (13% less capacity). The pack is UN38.3 certified for shipment and CE marked.

We tested this battery extensively in the lab and the field and we can confidently say that it’s a great fit for the BlueROV2. It can be used in exactly the same manner, including the same charger and charge settings. The only thing to keep in mind is that you should never connect batteries of different capacities in parallel, therefore never connect these batteries with the original black batteries in a parallel circuit!

Like our original battery, this battery is subject to international shipping restrictions and can only be shipped directly to certain countries. Many of our distributors around the world will have stock available in the future. Please see the product page for more details on shipping and availability in your country.

That’s all for today! Stay tuned for more updates in the future.

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Excellent job! It’s very beneficial to have an alternative battery to keep the BR community active.

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Hi Rusty ,
Hope you are doing well.
This message is just to get a clarity in paralleling batteries, I have seen your post about the new battery product and you have said that never connect batteries of different capacities in parallel, therefore never connect these batteries with the original black batteries in a parallel circuit! in your post. My question is ,whether paralleling is restricted just because of the battery chemistry difference ?

One more question is if i have an 18AH and 36AH batteries of same chemistry and same voltage (eg. Li ion ) , can I connect in parallel to get an endurance of 54AH ?

-Thanks

This page gives some insight into the important factors to consider when using batteries in parallel. The upshot is basically that even batteries of the same chemistry and brand can have different voltages if they’re different ages/have been used different amounts. If you measure their voltages and they’re exactly the same then it might be ok, but that also can’t be guaranteed over time because some batteries will lose capacity faster than others, even within the same pack.

This is part of why most Li-Ion battery packs come with a built in battery management system (BMS), to help ensure that the different battery cells are kept balanced and maximise battery performance and longevity. You might be interested in something like @seaview’s Multi-Battery Manager, although looking at their website it’s recently been discontinued in favour of their new/upcoming Power System Manager, which @gcelec might be able to provide some more information about :slight_smile:

Yes, we are about to release the Power System Manager (PSM). It has a higher voltage range than the Multi Battery Manager, switching capability and low voltage protection. Each battery requires a Power System Manager and you can parallel as many batteries as you like.
Basically, the power source with the highest voltage will be used until all power sources are balanced where they are drawn on equally.
You can also combine the PSM with an external power source to create a hybrid power system where the external power is used most of the time, while the battery cuts in during heavy current draw.

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