Sterling Battery-Battery Maintainer 12V-12V, 3A

Sterling Battery-Battery Maintainer 12V-12V, 3A

£86.24

(£71.87 Exc. VAT)

(9 Reviews)

3 in stock

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Product code

P02157

Brand

Sterling Power

Voltage

12-12V

Current Rating

Description

The Sterling Battery-Battery Maintainer is a simple, low cost solution to preventing your battery self-discharging and becoming damaged; keeping it in optimum condition and extending service life.

The Maintainer works by allowing some of the charging current supplied to one battery by a 12V DC charging source (e.g. mains charger, alternator, solar, wind) to be diverted to a second battery to keep it maintained. A typical use for this device would be where you have a leisure/auxiliary battery being charged by a mains charger or solar charger and you wanted to keep a starter battery maintained using some of this power. It can be used with any combination of battery chemistries (lead-acid & lithium for example), providing they are both at a nominal system voltage of 12V DC, and supplies a 3A max. charge current once the source battery has reached 13.3V. When the source battery reduces to 12.8V the unit will go into standby mode.

The Maintainer is simple to install, being fitted in-line between the positive terminals of the two batteries with 10A fuses (recommend by Sterling). It also requires a negative connection that must be 'common' with both batteries.

Its IP65 rating and ignition-protected design make it particularly suitable for use in harsh marine environments.

Features

3A max. trickle charge between two 12V batteries (or banks of batteries)
Works with all battery chemistries and combinations
LED indicator lights to show charging & battery status
Over-temp, over-voltage and reverse-polarity protection
Aux battery low-voltage warning
Low self-consumption (uses FETs rather than relays)
IP65 rating and ignition-protected for marine use

Further information

This device is not intended to be used to 'bulk' charge a heavily depleted battery as it has no multi-stage charge capability and the current is too limited. It is for maintenance charging to support small loads (approx. 0.5A continuous drain) and prevent self-discharge.

Specifications

Compatible battery types: Lead-acid (wet, gel, AGM) & lithium
Nominal system voltage of 'source' battery: 12V DC
Nominal system voltage of battery being charged: 12V DC
Max. trickle charging current: 3A
Activation voltage: 13.3V DC
De-activation (standby) voltage: 12.8V DC
Current self-consumption: <2mA
Protection rating: IP65
Reverse polarity protection: Yes (via on-board fuses)
Over-temperature protection: Yes (unit shuts down at 80°C)
Over-voltage protection threshold: 15.5V DC (unit will shut down)
Aux battery low voltage warning threshold: 12.6V DC and below
Ignition protected: Yes
Supplied cable length: 1m
Cable cross-section: 3mm² (12 AWG)
Overall dims: 140 (L) x 45 (W) x 40 (D) mm

Part Number : BM12123

Manuals & Guides

Customer Reviews (9)

Write a Review and share your opinions!

9 Reviews:

Near-unique product, works!

Rating:

12 August 2024 | Janne

I use the BM1212 on my boat, which has a 160W solar panel and 300 Ah of main batteries, to keep the starter battery, reserve starter battery and a tiny on-the-go 8 Ah AGM battery charged/topped up. All have the same (CTEK) connectors available in one location, so I just swap the connection when required.

Doesn't drain the main batteries too much (nor steal too much solar power from charging them). Also, any larger current would kill the 8 Ah battery, but this charges it at a convenient rate...

Only negative thing is zero availability within the EU (brexit, meh), but the 12V Planet web shop worked well, dropping the VAT.

Success after a false start

Rating:

04 June 2024 | Simon

Purchase this item in September and only just got round to fitting it (June!). Seemed to be dead. Call 12v planet. They explained return arrangement ( you get a free label off their website - pretty simple and effective) and said they would honour the return deal even though I was out of time.
So I deinstalled the unit, checking the input wires as I did so, surprise surprise, no current to the input. Further investigation revealed the fuse I had fitted next to the battery on the input feed had blown. New fuse, reinstall unit and all is well. This is a long way of saying two things- don’t put the fuse in live feed until the wiring is complete - doubtless mine blew while I was fixing it up when the end of the wire found earth somewhere. The second thing is to congratulate 12v Planet. I Really didn’t expect they would make it painless to return the unit after so long but their phone support is was really good, swift and helpful. They accepted a return straight away and explained how to do it. I should apologise too for waisting the help line’s time and ordering a return label I don’t need!

Nice and compact

Rating:

28 March 2024 | Tim

Does what it says and works perfectly

Sterling batt maintainer

Rating:

18 March 2024 | Rob

Bought this to ensure vehicle battery stays charged from solar panels when parked up for weeks. It was this or the battery master both do the same thing. Have bought Sterling products before so had no issues with quality. Also sterling unit had a higher output. Does exactly what it said it should, been in use for
several weeks now, no issues I'm hoping it's going to be fit and forget.

Battery maintainer

Rating:

12 November 2023 | Rossalyn

Quick delivery and good value. Working well so far.

Response:

Thank you for the great review

Start battery protection

Rating:

27 February 2023 | Desiree

Installed on Friday 24 th Feb. Immediate increase in voltage. Probably saved the batter's life, and it will be ready for immediate use when we return.
Love it!

Response:

Thank you for the feedback Desiree!

Sterling B2B maintainer

Rating:

01 August 2022 | John

Bought this unit for our motor caravan to maintain the starter battery's drain while in winter storage via our Victron solar charged leisure bank and so far it's doing a great job.

Sterling Battery-Battery Maintainer

Rating:

27 February 2022 | David

After taking advice from your tech team purchased this maintainer. Simply easy to fit instructions and does the job. One technical info missing from the instructions is that as soon as dark falls or a grey day the coloured led stop working. This first created a headache and after contacting the tech help it appeared to correct. So if this bit of info could be included I think will help other purchasers.

Prompt delivery as always, quality product.

Rating:

10 June 2021 | David

Brilliant service as always, Sterling battery to battery maintainer being used to feed back/ maintain started battery via solar. Working perfectly.

Sterling Power Products is at the forefront of battery charging and power management technology for both the professional and recreational consumer, with many years’ experience. Providing a vast range of products and solutions, this UK-based company uses its award-winning charging technology to minimise re-charge times and maximise service life by ensuring the optimum charging profiles for your battery system. Sterling Power Products is an extremely well known and trusted brand within the marine electronics market and offers a large range of DC-DC charging solutions for the automotive sector.